The 100 most-cited articles in ACS Applied Materials & Interfaces, 2023

The rapid development of wearable electronic devices and virtual reality technology has revived interest in flexible sensing and control devices. Here, we report an ionic hydrogel (PTSM) prepared from polypropylene amine (PAM), tannic acid (TA), sodium alginate (SA), and MXene. Based on the multiple weak H-bonds, this hydrogel exhibits excellent stretchability (strain >4600%), adhesion, and self-healing. The introduction of MXene nanosheets endows the hydrogel sensor with a high gauge factor (GF) of 6.6. Meanwhile, it also enables triboelectric nanogenerators (PTSM-TENGs) fabricated from silicone rubber-encapsulated hydrogels to have excellent energy harvesting efficiency, with an instantaneous output power density of 54.24 mW/m 2 . We build a glove-based human–computer interaction (HMI) system using PTSM-TENGs. The multidimensional signal features of PTSM-TENG are extracted and analyzed by the HMI system, and the functions of gesture visualization and robot hand control are realized. In addition, triboelectric signals can be used for object recognition with the help of machine…

Wearable non-invasive sensors facilitate the continuous measurement of glucose in sweat for the treatment and management of diabetes. However, the catalysis of glucose and sweat sampling are challenges in the development of efficient wearable glucose sensors. Herein, we report a flexible wearable non-enzymatic electrochemical sensor for continuous glucose detection in sweat. We synthesized a catalyst (Pt/MXene) by the hybridization of Pt nanoparticles onto MXene (Ti 3 C 2 T x ) nanosheets with a broad linear range of glucose detection (0–8 mmol/L) under neutral conditions. Furthermore, we optimized the structure of the sensor by immobilizing Pt/MXene with a conductive hydrogel to enhance the stability of the sensor. Based on Pt/MXene and the optimized structure, we fabricated a flexible wearable glucose sensor by integrating a microfluidic patch for sweat collection onto a flexible sensor. We evaluated the utility of the sensor for the detection of glucose in sweat, and the sensor could detect the glucose change with the replenishment and consumption of energy by the body, and a…

Flexible strain sensors have significant progress in the fields of human-computer interaction, medical monitoring, and handwriting recognition, but they also face many challenges such as the capture of weak signals, comprehensive acquisition of the information, and accurate recognition. Flexible strain sensors can sense externally applied deformations, accurately measure human motion and physiological signals, and record signal characteristics of handwritten text. Herein, we prepare a sandwich-structured flexible strain sensor based on an MXene/polypyrrole/hydroxyethyl cellulose (MXene/PPy/HEC) conductive material and a PDMS flexible substrate. The sensor features a wide linear strain detection range (0-94%), high sensitivity (gauge factor 357.5), reliable repeatability (>1300 cycles), ultrafast response-recovery time (300 ms), and other excellent sensing properties. The MXene/PPy/HEC sensor can detect human physiological activities, exhibiting excellent performance in measuring external strain changes and real-time motion detection. In addition, the signals of English words, Arabic…

A Pt/MoS 2 /polyaniline (Pt/MoS 2 /PANI) nanocomposite is successfully synthesized by the hydrothermal process combined with the in situ polymerization method, and then Pt particles are decorated on its surface. The Pt/MoS 2 /PANI nanocomposite is deposited on a flexible Au-interdigitated electrode of a polyimide (PI) film. The flexible sensor exhibits a higher response value and fast response/recovery time to NH 3 at room temperature (RT). It results in 2.32-fold and 1.13-fold improvement in the gas-sensing response toward 50 ppm NH 3 compared to those of PANI and MoS 2 /PANI-based gas sensors. The detection limit is 250 ppb. The enhancement sensing mechanisms are attributed to the p–n heterojunction and the Schottky barrier between the three components, which has been confirmed by the current–voltage ( I – V ) curves. A satisfactory selectivity to NH 3 against trimethylamine (TMA) and triethylamine (TEA) is obtained according to density functional theory (DFT), Bader’s analysis, and differential charge density to illustrate the adsorption behavior and charge transfer of gas…

Polymers that integrate multiple functions into one system broaden the application range of materials, but it remains a great challenge to obtain polymer materials with simultaneously high strength, high toughness, and high self-healing rate. In this work, we prepared waterborne polyurethane (WPU) elastomers using Schiff bases containing disulfide and acylhydrazone bonds (PD) as chain extenders. Acylhydrazone forming a hydrogen bond not only acts as a physical cross-linking point, which promotes the microphase separation of polyurethane to increase the thermal stability, tensile strength, and toughness of the elastomer, but also serves as a “clip” to integrate various dynamic bonds together to synergistically reduce the activation energy of the polymer chain movement and endow the molecular chain with faster fluidity. Therefore, WPU-PD exhibits excellent mechanical properties at room temperature, such as a tensile strength and a fracture energy of 25.91 MPa and 121.66 kJ m –2, respectively, and a high self-healing efficiency of 93.7% in a short time under moderate heating…

Conductive hydrogels are ideal for flexible sensors, but it is still a challenge to produce such hydrogels with combined toughness, self-adhesion, self-healing, anti-freezing, moisturizing, and biocompatibility properties. Herein, inspired by natural skin, a highly stretchable, strain-sensitive, and multi-environmental stable collagen-based conductive organohydrogel was constructed by using collagen (Col), acrylic acid, dialdehyde carboxymethyl cellulose, 1,3-propylene glycol, and AlCl 3 . The resulting organohydrogel exhibited excellent tensile (strain >800%), repeatable adhesion (>10 times), self-healing [self-healing efficiency (SHE) ≈ 100%], anti-freezing (−60 °C), moisturizing (>20 d), and biocompatible properties. This organohydrogel also possessed good electrical conductivity (σ = 3.4 S/m) and strain-sensitive properties [GF (gauge factor) = 13.65 with the maximal strain of 400%]. Notably, the organohydrogel had a considerable low-temperature self-healing performance (SHE = 88% at −24 °C) and rapid underwater self-healing property (SHE = 92%, self-healing time <20 min). This…

Bacterial infection and excess reactive oxygen species are key factors that lead to slow or substantially delayed wound healing. It is crucial to design and develop new nanomaterials with antibacterial and antioxidative capabilities for wound healing. Here, positively charged carbon dots (CDs) are rationally designed and synthesized from p -phenylenediamine and polyethyleneimine by a facile one-pot solvothermal method, which show good biocompatibility in in vitro cytotoxicity, hemolysis assays, and in vivo toxicity evaluation. The positively charged CDs show superior antimicrobial effect against Staphylococcus aureus ( S. aureus ) at very low concentrations, reducing the risk of wound infection. At the same time, CDs with surface defects and unpaired electrons can effectively scavenge excess free radicals to reduce oxidative stress damage, accelerate wound inflammation–proliferation transition, and promote wound healing. The mouse model of skin infection demonstrates that CDs can effectively promote the wound healing of skin infection without obvious side effects by simply dropping…

Lanthanide-doped upconversion nanoparticles (UCNPs) possess the remarkable ability to convert multiple near-infrared (NIR) photons into higher energy ultraviolet-visible (UV-vis) photons, making them a prime candidate for several advanced applications within the realm of nanotechnology. Compared to traditional organic fluorophores and quantum dots (QDs), UCNPs possess narrower emission bands (fwhm of 10-50 nm), large anti-Stokes shifts, low toxicity, high chemical stability, and resistance to photobleaching and blinking. In addition, unlike UV-vis excitation, NIR excitation is nondestructive at lower power intensities and has high tissue penetration depths (up to 2 mm) with low autofluorescence and scattering. Together, these properties make UCNPs exceedingly favored for advanced bioanalytical and theranostic applications, where these systems have been well-explored. UCNPs are also well-suited for bioimaging, optically modulating chemistries, forensic science, and other state-of-the-art research applications. In this review, an up-to-date account of emerging applications in UCNP…

Exploring electromagnetic interference (EMI) shielding materials with ultra-efficient EMI shielding effectiveness (SE) and an absorption-dominated mechanism is urgently required for fundamentally tackling EMI radiation pollution. Herein, zeolitic imidazolate framework-67 (ZIF-67)/MXene/cellulose aerogels were first prepared via a simple solution mixing-regeneration and freeze-drying process. Subsequently, they are converted into electric/magnetic hybrid carbon aerogels (Co/C/MXene/cellulose-derived carbon aerogels) through a facile pyrolysis strategy. ZIF-67-derived porous Co/C could provide the additional magnetic loss capacity. The resultant electric/magnetic hybrid carbon aerogels exhibit a hierarchically porous structure, complementary electromagnetic waves (EMWs) loss mechanisms, and abundant heterointerfaces. The construction of a porous architecture and the synergy of electric/magnetic loss could greatly alleviate the impedance mismatching at the air–specimen interface, which enables more EMWs to enter into the materials for consumption. Moreover, numerous heterointerfaces…

Bioactive hydrogels self-assembled from naturally occurring herbal small molecules are attracting growing interest for applications in wound healing, due to their versatile intrinsic biological activities, excellent biocompatibility, as well as facile, sustainable, and eco-friendly processes. However, the development of supramolecular herb hydrogels with sufficient strength and multifunctionality as an ideal wound dressing in clinical practice remains a challenge. In this work, inspired by the efficient clinic therapy and directed self-assembly of natural saponin glycyrrhizic acid (GA), we create a novel GA-based hybrid hydrogel to promote full-thickness wound healing and bacterial-infected wound healing. This hydrogel possesses excellent stability and mechanical performance and multifunctional properties, including injectable, shape-adaptation and remodeling, self-healing, and adhesive abilities. This is attributed to the hierarchical dual-network that comprises the self-assembled hydrogen-bond fibrillar network of aldehyde-contained GA (AGA) and the dynamic covalent network…

Green and environment-friendly preparation are of the utmost relevance to the development of transparent antismudge coatings. To prepare a waterborne polyurethane (WPU) coating with antismudge property, it is challenging to balance the stability of dispersion and the antismudge property of coating. Herein, we prepare a transparent bio-based WPU coating grafted with a minor proportion of poly(dimethylsiloxane) (WPU- g -PDMS) using renewable castor oil, monocarbinol-terminated PDMS, hexamethylene diisocyanate trimer, and 2,2-bis(hydroxymethyl)propionic acid as raw materials. Effects of the dosage of monocarbinol-terminated PDMS, the curing temperature, and the curing time on the antismudge performance were studied. Results showed that rigorous stirring (3000 rpm) is necessary to obtain a stable WPU- g -PDMS dispersion with a storage time longer than 6 months. A high curing temperature (>160 °C) and a period of curing time (>1 h) are indispensable to obtain the excellent antismudge property because they would facilitate the grafted low-surface-tension PDMS chains to migrate from the…

It is essential and challenging to develop advanced ceramic materials with thermal stability and high reflectivity for optical fields. Encouragingly, recent breakthroughs and significant advances in high-entropy ceramics have made high-entropy oxides a potential candidate material for optical applications. Therefore, in this study, we analyzed the effect of lattice distortion on the design of high-reflectivity, high-entropy oxides using first-principles calculations and aberration-corrected microscopy. In order to optimize the optical properties of the materials, a series of novel perovskite-type high-entropy oxides, (La x K 0.4– x Ca 0.2 Sr 0.2 Ba 0.2 )TiO 3+δ ( x = 0.1, 0.15, 0.2, 0.25, 0.3), were designed and synthesized using solid-state sintering based on the charge conservation principle and bond energy principle. When the content of La in the A-site element was 30%, the optical reflectivity reached 94% by suppressing the oxygen vacancy. Furthermore, we have successfully prepared a series of coatings by air spraying based on the regulation of the mass ratio of resin and…

The maskless and chemical-free conversion and patterning of synthetic polymer precursors into laser-induced graphene (LIG) via laser-induced pyrolysis is a relatively new but growing field. Bioderived precursors from lignocellulosic materials can also be converted to LIG, opening a path to sustainable and environmentally friendly applications. This review is designed as a starting point for researchers who are not familiar with LIG and/or who wish to switch to sustainable bioderived precursors for their applications. Bioderived precursors are described, and their performances (mainly crystallinity and sheet resistance of the obtained LIG) are compared. The three main fields of application are reviewed: supercapacitors and electrochemical and physical sensors. The key advantages and disadvantages of each precursor for each application are discussed and compared to those of a benchmark of polymer-derived LIG. LIG from bioderived precursors can match, or even outperform, its synthetic analogue and represents a viable and sometimes better alternative, also considering its low cost and…

Antibiotic resistance reduces the effectiveness of infected wound healing, and it is necessary to develop a new strategy to promote infected wound healing without using antibiotics. Here, we develop a Chlorin e6 (Ce6)-loaded zinc-metal-organic framework (MOF) thermosensitive hydrogel (Ce6@MOF-Gel) based on alginate and poly(propylene glycol) 407, which enhances antibacterial effects and promotes infected wound healing by a novel strategy of combining zinc-MOF with photodynamic therapy (PDT). Zinc-MOF can realize acid-responsive release of Ce6 and improve antibacterial performance without drug resistance by destroying the integrity of bacterial cell membranes and enhancing the production of bacterial reactive oxygen species (ROS). Additionally, Ce6@MOF-Gel enhances the stability, solubility, and photodynamic properties of Ce6. More importantly, Ce6@MOF-Gel reduces inflammation and promotes collagen deposition and re-epithelialization to facilitate infected wound healing. Collectively, the photodynamic MOF-based hydrogel provides a new, efficient, and safe way for accelerated healing…

Thermochromic smart windows are considered to be promising energy-saving devices for reducing energy consumption in buildings. The ideal materials for thermochromic smart windows should have high transmittance, high solar modulation, low phase-transition temperature, and excellent high-temperature thermal stability, which are difficult to achieve simultaneously. This work reports a simple one-step low-temperature polymerization method to prepare a thermo-responsive poly( N -isopropylacrylamide)/hydroxypropylmethyl cellulose (PNIPAM/HPMC) hydrogel achieving the above performances simultaneously. The low-temperature polymerization environment endowed the hydrogel with a high luminous transmittance ( T lum ) of 90.82%. HPMC as a functional material effectively enhanced the mechanical properties and thermal stability of the hydrogel. Meanwhile, the PNIPAM/HPMC hydrogel showed a low phase-transition temperature (∼32 °C) and high solar modulation (Δ T sol = 81.52%), which proved that it is an ideal material for thermochromic smart windows. Moreover, a PNIPAM/HPMC smart window exhibited…

Flexible sensors have attracted increasing attention owing to their important applications in human activity monitoring, medical diagnosis, and human–machine interaction. However, the rational design of low-cost sensors with desirable properties (e.g., high sensitivity and excellent stability) and extended applications is still a great challenge. Herein, a simple and cost-effective strategy is reported by immersing polyurethane (PU) sponge in graphene oxide solution followed by in situ chemical reduction to construct a reduced graphene oxide (RGO)-wrapped PU sponge sensor. Ascribed to the excellent compressive resilience of PU sponge and an electrically conductive RGO layer, the constructed flexible sensor exhibits satisfactory sensing performance with high sensitivity (17.65 kPa –1 ) in a low-load range (0–3.2 kPa), a wide compression strain range (0–80%), and reliable stability (8000 cycles). In addition, these sensors can be successfully applied to monitor human movements and identify the weight of objects. Through the use of a sensor array integrated with a signal acquisition…

Solar-powered interfacial evaporation has been recognized to be a promising and sustainable technology for seawater desalination, in view of the challenge of freshwater scarcity and fossil energy storage. Nevertheless, current cutting-edge interfacial evaporation systems mostly ignore the issues of intermittent solar irradiation and bacterial contamination. We have hereby developed a novel type of an interfacial evaporator equipped with carbon black (CB)/chitosan (CS)-decorated phase-change microcapsules as a multifunctional photothermal material for solar-powered seawater desalination, based on a highly efficient, antibacterial, and salt-resistant multipurpose strategy. In the developed microcapsules, an n -docosane phase-change material (PCM) core was engulfed in a TiO 2 shell, followed by surface decorating a CB/CS nanocomposite layer. A high thermal energy-storage capacity of more than 140 J g –1 was achieved, thanks to tight sealing of n -docosane as a PCM core in the perfect core–shell structured microcapsules. Moreover, a rational combination of CS and CB nanoparticles not…

Conductive hydrogels have attracted tremendous interest in the construction of flexible strain sensors and triboelectric nanogenerators (TENGs) owing to their good stretchability and adjustable properties. Nevertheless, how to simultaneously achieve high transparency, self-healing, adhesion, antibacterial, anti-freezing, anti-drying, and biocompatibility properties through a simple method remains a challenge. Herein, a transparent, freezing-tolerant, and multifunctional organohydrogel (PAOAM-PDO) as electrode for strain sensors and TENGs was constructed through a free radical polymerization in the 1,3-propanediol (PDO)/water binary solvent system, in which oxide sodium alginate, aminated gelatin, acrylic acid, and AlCl 3 were used as raw materials. The obtained PAOAM-PDO exhibited good transparency (>90%), self-healing, adhesiveness, antibacterial property, good conductivity (1.13 S/m), and long-term environmental stability. The introduction of PDO endowed PAOAM-PDO with freezing resistance with a low freezing point of −60 °C, and PAOAM-PDO could serve as a protective skin barrier…

Ideal periosteum materials are required to participate in a sequence of bone repair-related physiological events, including the initial immune response, endogenous stem cell recruitment, angiogenesis, and osteogenesis. However, conventional tissue-engineered periosteal materials have difficulty achieving these functions by simply mimicking the periosteum via structural design or by loading exogenous stem cells, cytokines, or growth factors. Herein, we present a novel biomimetic periosteum preparation strategy to comprehensively enhance the bone regeneration effect using functionalized piezoelectric materials. The resulting biomimetic periosteum possessing an excellent piezoelectric effect and improved physicochemical properties was prepared using a biocompatible and biodegradable poly(3-hydroxybutyric acid- co -3-hydrovaleric acid) (PHBV) polymer matrix, antioxidized polydopamine-modified hydroxyapatite (PHA), and barium titanate (PBT), which were further incorporated into the polymer matrix to fabricate a multifunctional piezoelectric periosteum by a simple one-step spin-coating…

Overcoming ice accretion on external aircraft wing surfaces plays a crucial role in aviation, and developing environmentally friendly passive anti-icing surfaces is considered to be a promising strategy. Superhydrophobic surfaces (SHSs) have attracted increasing attention due to their potential advantages of keeping the airframe dry without causing additional aerodynamic losses. However, the passive anti-icing performances of SHSs reported to date varied a lot under different icing test conditions. Therefore, a systematic investigation is necessary to elucidate the icing conditions where SHSs can remain effective and pave the way for SHSs toward practical anti-icing applications. Herein, we designed and fabricated a typical type of SHS featuring dual-scale hierarchical structures with arrayed micromountains (with both spacings and heights of tens of micrometers) covered by single-scale sandy-corrugation-like periodic structures (with both spacings and heights of only several micrometers) (termed SS1). Its anti-icing performances under three representative icing conditions, including…

Flexible strain sensors based on self-adhesive, high-tensile, super-sensitive conductive hydrogels have promising application in human-computer interaction and motion monitoring. Traditional strain sensors have difficulty in balancing mechanical strength, detection function, and sensitivity, which brings challenges to their practical applications. In this work, the double network hydrogel composed of polyacrylamide (PAM) and sodium alginate (SA) was prepared, and MXene and sucrose were used as conductive materials and network reinforcing materials, respectively. Sucrose can effectively enhance the mechanical performance of the hydrogels and improve the ability to withstand harsh conditions. The hydrogel strain sensor has excellent tensile properties (strain >2500%), high sensitivity with a gauge factor of 3.76 at 1400% strain, reliable repeatability, self-adhesion, and anti-freezing ability. Highly sensitive hydrogels can be assembled into motion detection sensors that can distinguish between various strong or subtle movements of the human body, such as joint flexion and throat…

The advent of near-infrared (NIR) afterglow in Cr 3+ -doped materials has stimulated considerable interest in technological applications owing to the sustainable emission of light with good penetrability. However, the development of Cr 3+ -free NIR afterglow phosphors with high efficiency, low cost, and precise spectral tunability is still an open question. Herein, we report a novel Fe 3+ -activated NIR long afterglow phosphor composed of Mg 2 SnO 4 (MSO), in which Fe 3+ ions occupy the tetrahedral [Mg–O 4 ] and octahedral [Sn/Mg–O 6 ] sites, giving rise to a broadband NIR emission spanning 720–789 nm. On account of energy-level alignment, the electrons released from the traps show a preferential return to the excited energy level of Fe 3+ in tetrahedral sites through tunneling, leading to a single-peak NIR afterglow centered at 789 nm with a full-width at half-maximum (fwhm) of 140 nm. The high-efficiency NIR afterglow, showing a record persistent time lasting over 31 h among Fe 3+ -based phosphors, is demonstrated as a self-sustainable light source for night vision applications.…

It has been confirmed that substantial vascularization is an effective strategy to heal large-scale bone defects in the field of bone tissue engineering. The local application of deferoxamine (DFO) is among the most common and effective methods for promoting the formation of blood vessels, although its short half-life in plasma, rapid clearance, and poor biocompatibility limit its therapeutic suitability. Herein, zeolitic imidazolate framework-8 (ZIF-8) was selected as a vehicle to extend the half-life of DFO. In the present study, a nano DFO-loaded ZIF-8 (DFO@ZIF-8) drug delivery system was established to promote angiogenesis–osteogenesis coupling. The nanoparticles were characterized, and their drug loading efficiency was examined to confirm the successful synthesis of nano DFO@ZIF-8. Additionally, due to the sustained release of DFO and Zn 2+, DFO@ZIF-8 NPs were able to promote angiogenesis in human umbilical vein endothelial cells (HUVECs) culture and osteogenesis in bone marrow stem cells (BMSCs) in vitro. Furthermore, the DFO@ZIF-8 NPs promoted vascularization by enhancing the…

Antibacterial hydrogel wound dressings with adhesive and antioxidant activity are desirable for treating skin injuries in clinical care. Hereby, a series of multifunctional hydrogel wound dressings with high adhesive, self-healing, antioxidant, and antibacterial activity were designed and fabricated using dopamine (DA) and quercetin (QT). The multifunctional hydrogels were constructed by the interpenetrated quaternized chitosan chain segments and polyacrylamide network. The catechol groups on DA, QT, and the quaternary ammonium groups in the hydrogel system endow hydrogels with high strength, excellent adhesion, and self-healing ability. The results confirmed the admirable hemocompatibility and remarkable antibacterial activity of the multifunction hydrogels against Staphylococcus aureus and Escherichia coli . Consequently, multifunction hydrogels with satisfactory adhesive and antibacterial activity are appropriate alternative materials in the fields of tissue adhesive and wound dressing applications.

The present work focuses on the synthesis and properties of a novel multifunctional cerium(III) MOF, [Ce 2 (data) 3 (DMF) 4 ]·DMF (data 2–: 2,5-diaminoterephthalate), abbreviated as NH 2 -Ce-MUM-2. Its crystal structure reveals an intricate 3D 4,5-connected framework with a xah topology. This MOF features unique properties, such as open metal sites, presence of free amino groups, and high stability. Two main applications of NH 2 -Ce-MUM-2 were investigated: (i) as a heterogeneous catalyst in the CO 2 fixation into cyclic carbonates and (ii) as a material with third-order nonlinear optical activity. As a model reaction, the cycloaddition of CO 2 to propylene oxide to give the corresponding cyclic carbonate was explored under mild conditions, at the atmospheric pressure of carbon dioxide and in the absence of cocatalyst and added solvent. Various reaction parameters were investigated toward optimization and exploration of substrate scope, revealing up to 99% product yields of cyclic carbonate products. Besides, the structure of NH 2 -Ce-MUM-2 is highly stable, permitting its…

Triethylamine (TEA) is a flammable and highly toxic gas, and the fast, accurate, and sensitive detection of gas TEA remains greatly challenging. Herein, we report a ZnO nanorod anchored with a single-atom Pt catalyst (Pt 1 /ZnO) as a gas sensor for TEA detection. The sensor shows high selectivity and high response to gas TEA with a response value of 4170 at 200 °C, which is 92 times higher than that of pure ZnO. Moreover, the Pt 1 /ZnO sensor has very short response and recovery times of only 34 and 76 s, respectively, and also has a high response to ppb-level TEA gas (100 ppb-21.6). The gas-sensing enhancement mechanism of the Pt 1 /ZnO sensor to gas TEA was systematically investigated using band structure analysis, in situ diffuse reflectance infrared Fourier transformation spectroscopy, and density functional theory calculations. The results show that the oxygen vacancies on Pt 1 /ZnO can effectively activate the adsorbed oxygen. Moreover, chemical bonds can be formed between Pt single atoms and N atoms in TEA to achieve effective adsorption and activation of TEA molecules,…

Aerogel fibers inherit the merits of aerogel and fibrous materials, such as high porosity and satisfactory knittability, demonstrating great potential as thermal protective materials applied in harsh environments. Nevertheless, the inferior mechanical property resulting from the porous structure immensely hampers the practical application of aerogel fibers. Herein, we develop robust and thermally insulating long polyimide fiber-reinforced polyimide composite aerogel fibers (LPF-PAFs). The porous crosslinked polyimide aerogel as the sheath endows LPF-PAFs with good thermal insulation performance, while the long polyimide fibers as the core provide LPF-PAFs with superior mechanical strength. Due to the introduction of the high-strength long polyimide fibers to undertake significant stress, LPF-PAFs display outstanding strength surpassing 150 MPa without obvious mechanical performance degeneration in a wide range of temperatures from -100 to 300 °C. Moreover, the textile woven by LPF-PAFs exhibits a superior thermal insulation ability and stability to cotton textile at 200 and -100 °C,…

Detection of ultralow concentrations of ammonia is very important in many applications such as fishing, poultry, agriculture, industry, biomedicine, and clinical diagnosis. However, detecting sub-ppm NH 3 remains a challenge for chemiresistive-type gas sensors. Two-dimensional (2D) materials display tremendous potential for effective gas detectors that can be used in these applications. The as-developed MXene/SnS 2 heterojunction-based chemiresistive-type sensor presents superior gas-sensing performance toward sub-ppm ammonia at room temperature. The sensor can detect NH 3 concentrations down to 10 ppb at room temperature. It also displays excellent long-term stability, with a decline in the response at ∼3.4% for 20 days. The developed sensor also displays good selectivity toward NH 3 relative to some potential interferents, such as HCHO, C 2 H 5 OH, CH 3 OH, C 3 H 6 O, benzene, and NO 2 . The measured in situ diffuse-reflectance infrared Fourier transform (DRIFT) spectra confirm that the products of nitric oxides during the chemical reactions occurred at the surface of MXene/SnS 2…

Although mutually independent, simultaneous sound absorption and superior mechanical properties are often sought after in a material. One main challenge in achieving such a material will be on how to design it. Herein, we propose a bamboo-inspired design strategy to overcome the aforementioned challenges. Building on top of the basic octet-truss design, we introduce a hollow-tube architecture to achieve lightweight property and mechanical robustness and a septum-chamber architecture to introduce acoustic resonant cells. The concept is experimentally verified through samples fabricated using selective laser melting with the Inconel 718 alloy. High sound absorption coefficients (>0.99) with broadband spectra, damage-tolerant behavior, high specific strength (up to 81.2 MPa·cm 3 /g), and high specific energy absorption of 40.1 J/g have been realized in this design. The sound absorption capability is attributed to Helmholtz resonance through the pore-and-cavity morphology of the structure. Microscopically speaking, dissipation primarily occurs via the viscous frictional flow and thermal…

O3-type layered oxides with high initial sodium content are promising cathode candidates for Na-ion batteries. However, affected by the undesired transition metal slab sliding and reaction with H 2 O/CO 2, their further application is typically hindered by unsatisfactory cycling stability upon charging to high voltage and poor storage stability under humid air. Herein, we demonstrate a Fe/Ti cosubstitution strategy to simultaneously enhance the electrochemical performance and storage stability of pristine O3-NaNi 0.5 Mn 0.5 O 2 cathode material, via employing high redox potential and inactive stabilized dopants. The resultant Fe/Ti cosubstituted Na 0.95 Ni 0.40 Fe 0.15 Mn 0.3 Ti 0.15 O 2 undergoes highly reversible O3–P3–OP2 phase transitions with a small cell volume change of 2.8%, instead of complex O3–O′3–P3–P′3–P3′–O1 phase transitions in NaNi 0.5 Mn 0.5 O 2 . Consequently, the cathode displays a high specific capacity of 161.6 mAh g –1 with an average working voltage of 3.28 V and 81.8% capacity retention after 200 cycles at 5 C . Furthermore, the cathode material remains very…

Passive radiative cooling textiles can reflect sunlight and dissipate heat directly to the outside space without any energy input. However, radiative cooling textiles with high performance, large scalability, cost effectiveness, and high biodegradability are still uncommon. Herein, we exploit a porous fiber-based radiative cooling textile (PRCT) via nonsolvent-induced phase separation and scalable roll-to-roll electrospinning technology. Nanopores are introduced into single fibers, and the pore size can be accurately optimized by managing the relative humidity of the spinning environment. The anti-ultraviolet radiation and superhydrophobicity of textiles were improved by the introduction of core–shell silica microspheres. An optimized PRCT yields a strong solar reflectivity of 98.8% and atmospheric window emissivity of 97%, which results in a sub-ambient temperature drop of 4.5 °C, with the solar intensity over 960 W·m –2 and 5.5 °C at night. For personal thermal management, it is demonstrated that the PRCT can obtain a temperature drop of 7.1 °C compared to the bare skin under…

Photocatalytic reduction of CO 2 into valuable hydrocarbon fuels is one of the green ways to solve the energy problem and achieve carbon neutrality. Exploring photocatalyst with low toxicity and high-efficiency is the key to realize it. Here we report a lead-free halide perovskite-based 0D/2D Cs 3 Bi 2 Br 9 /Bi 2 WO 6 (CBB/BWO) S-scheme heterojunction for CO 2 photoreduction, prepared by a facile electrostatic self-assembly approach. The CBB/BWO shows superior photoreduction of CO 2 under visible light with CO generation rate of 220.1 μmol·g –1 ·h –1, which is ∼115.8 and ∼18.5 times higher than that of Cs 3 Bi 2 Br 9 perovskite quantum dots (CBB PQDS) and Bi 2 WO 6 nanosheets (BWO NS), respectively. The improved photocatalytic activity can be attributed to the tight 0D/2D structure and S-scheme charge transfer pathway between the Cs 3 Bi 2 Br 9 PQDS and atomic layers of the Bi 2 WO 6 NS, which shortens transmission distance of photogenerated carriers and boosts efficient separation and transfer of the carriers. This work provides insight in manufacturing potential lead-free…

It is important to have sustainable and edible scaffolds to produce cultivated meat. In this research, three-dimensional (3D) porous scaffolds were developed by soy protein amyloid fibrils for cultivated meat applications. Food-safe biological and physical cross-linking methods using microbial transglutaminase and temperature-controlled water vapor annealing technique were employed to crosslink soy protein amyloid fibrils, resulting in the production of 3D scaffolds. The generated 3D scaffolds had pores with sizes ranging from 50 to 250 μm, porosities of 72-83%, and compressive moduli of 3.8-4.2 kPa, depending on the type of soy protein used in the process (β-conglycinin (7S), glycinin (11S) and soy protein isolate (SPI)). When present with pepsin, these scaffolds can degrade within an hour but remain stable in phosphate-buffered saline for at least 30 days. The soy protein amyloid fibril scaffolds enabled C2C12 mouse skeletal myoblasts proliferate and differentiate without adding cell adhesive proteins or other coatings. The results demonstrate the potential of abundant and…

The mechanical durability of superhydrophobic surfaces is of significance for their practical applications. However, few reports about superhydrophobic coating on certain substrates took into consideration both the mechanical stability of the superhydrophobic coating and adhesion stability between the coating and the substrate. Herein, we put forward a facile and efficient strategy to construct robust superhydrophobic coatings by simply spray-coating a composite suspension of SiO 2 nanoparticles, polydimethylsiloxane (PDMS), and epoxy resin (EP) on substrates pretreated with an EP base-coating. The as-obtained coating exhibited excellent superhydrophobicity with water contact angle of 163° and sliding angle of 3.5°, which could endure UV irradiation of 180 h, immersion in acidic or basic solutions for 168 h, and outdoor exposure for over 30 days. Notably, the coating surface retained superhydrophobicity after being successively impacted with faucet water for 1 h, impinged with 360 g sand grains, and abraded with sandpaper of 120 grid under a load of 500 g for 5 m distance. The…

Flexible pressure sensors can be used in human–computer interaction and wearable electronic devices, but one main challenge is to fabricate capacitive sensors with a wide pressure range and high sensitivity. Here, we designed a capacitive pressure sensor based on a bionic cheetah leg microstructure, validated the benefits of the bionic microstructure design, and optimized the structural feature parameters using 3D printing technology. The pressure sensor inspired by the cheetah leg shape has a high sensitivity (0.75 kPa –1 ), a wide linear sensing range (0–280 kPa), a fast response time of roughly 80 ms, and outstanding durability (24,000 cycles). Furthermore, the sensor can recognize a finger-operated mouse, monitor human motion, and transmit Morse code information. This work demonstrates that bionic capacitive pressure sensors hold considerable promise for use in wearable devices.

Blue InGaN chip-pumped short-wave infrared (SWIR) emitters have aroused tremendous attention and shown emerging applications in diverse fields such as healthcare, retail, and agriculture. However, discovering blue light-emitting diode (LED)-pumped SWIR phosphors with a central emission wavelength over 1000 nm remains a significant challenge. Herein, we demonstrate the efficient broadband SWIR luminescence of Ni 2+ by simultaneously incorporating Cr 3+ and Ni 2+ ions into the MgGa 2 O 4 lattice, with Cr 3+ as the sensitizer and Ni 2+ as the emitter. Because of the strong blue light absorption of Cr 3+ and high energy transfer efficiency to Ni 2+, the obtained MgGa 2 O 4:Cr 3+, Ni 2+ phosphors show intense SWIR luminescence with a peak wavelength at 1260 nm and a full width at half maximum (FWHM) of 222 nm under the excitation of blue light. The optimized SWIR phosphor presents an ultra-high SWIR photoluminescence quantum efficiency of 96.5% and outstanding luminescence thermal stability (67.9%@150 °C). A SWIR light source has been fabricated through a combination of the prepared MgGa…

High Resolution Image Download MS PowerPoint Slide Cost-effective and high-performance H 2 S sensors are required for human health and environmental monitoring. 2D transition-metal carbides and nitrides (MXenes) are appealing candidates for gas sensing due to good conductivity and abundant surface functional groups but have been studied primarily for detecting NH 3 and VOCs, with generally positive responses that are not highly selective to the target gases. Here, we report on a negative response of pristine Ti 3 C 2 T x thin films for H 2 S gas sensing (in contrast to the other tested gases) and further optimization of the sensor performance using a composite of Ti 3 C 2 T x flakes and conjugated polymers (poly[3,6-diamino-10-methylacridinium chloride- co -3,6-diaminoacridine-squaraine], PDS-Cl) with polar charged nitrogen. The composite, preserving the high selectivity of pristine Ti 3 C 2 T x, exhibits an H 2 S sensing response of 2% at 5 ppm (a thirtyfold sensing enhancement) and a low limit of detection of 500 ppb. In addition, our density functional theory calculations…

Pesticide residues are a global threat to human health, and conventional sensors fail to simultaneously detect pesticide residues on the surface and inside agricultural products. In this work, we present a new microneedle (MN) patch-based surface-enhanced Raman spectroscopy (SERS) sensor. The needles and the basement of MNs can simultaneously detect pesticide residues on the surface and inside agricultural products. The Ag nanoparticles and sodium hyaluronate/poly(vinyl alcohol) (HA/PVA) hydrogel used in this MN patch-based sensor efficiently amplify the Raman signals of the pesticide residues. In addition, the HA/PVA hydrogel can effectively and quickly collect the residues, allowing this sensor to detect pesticide residues more conveniently. Furthermore, the stepped structure of the MNs increases the sensor’s surface area. Experimental results show that the sensor can detect thiram and thiabendazole (TBZ) pesticide residues with detection limits of 10 –7 and 10 –8 M, respectively. The detection process is minimally invasive and not harmful to agricultural products. The application…

Inspired by the interlocked biological geometry of human skin, herein, we design a flexible and transparent sensor with interlocked square column arrays with composites of Ag nanoparticles (AgNPs), citric acid (CA), and poly(vinyl alcohol) (PVA), which exhibit multisensory capabilities for pressure, temperature, and humidity. As a flexible pressure sensor, the interlocked AgNPs/CA/PVA sensor possesses a high sensitivity (−1.82 kPa –1 ), low detection limit (10 Pa), fast response (75 ms), and outstanding stability due to the high sensitivity of the contact resistance of the interlocked square column arrays to pressure. Because of the rigid dependence of the resistance of the AgNPs/CA/PVA composite on temperature, the interlocked AgNPs/CA/PVA sensor can also act as a temperature sensor, which exhibits high resolution (0.1 °C) and reliability in detecting ambient temperature. In addition, it is found that the amount of water molecules adsorbed by PVA and CA changes with the ambient humidity. Therefore, the interlocked AgNPs/CA/PVA sensor is also able to detect humidity in real time.…

Although relaxor ferroelectrics have been widely investigated owing to their various advantages, there are still impediments to boosting their energy-storage density ( W rec ) and energy-storage efficiency ( η ). In this paper, we propose a cooperative optimization strategy for achieving comprehensive outstanding energy-storage performance in (Na 0.5 Bi 0.5 ) 0.7 Sr 0.3 TiO 3 (NBST)-based ceramics by triggering a nonergodic-to-ergodic transformation and optimizing the forming process. The first step of substituting NaNbO 3 (NN) for NBST generated an ergodic state and induced polar nanoregions under the guidance of a phase-field simulation. The second step was to apply a viscous polymer process (VPP) to the 0.85NBST-0.15NN ceramics, which reduced porosity and increased compactness, resulting in a significant polarization difference and high breakdown strength. Consequently, 0.85NBST-0.15NN-VPP ceramics optimized by this cooperative two-step strategy possessed improved energy-storage characteristics ( W rec = 7.6 J/cm 3, η = 90%) under 410 kV/cm as well as reliable temperature…

Cotton fabrics with superhydrophobic, antibacterial, UV protection, and photothermal properties were developed using Ag/PDMS coatings, and the role of coating formulations on the obtained functionalities was studied. Specific attention was paid to understanding the relationships between the fabrics’ superhydrophobicity and antibacterial activity against Escherichia coli ( E. coli ) bacteria. UV protection performance of Ag/PDMS coatings was thoroughly evaluated based on the variation of UV transmission rate through coated fabrics and photoinduced chemiluminescence spectra. Moreover, the effect of silver nanoparticles (Ag NPs) and PDMS on developing a photothermal effect on fabrics was discussed. It was found that the content of Ag NPs and PDMS played critical roles in determining the water contact angle (WCA) on modified fabrics. The largest WCA was 171.31°, which was durable even after numerous accelerated wash cycles and abrasions. Antibacterial activity of fabrics showed the positive effect of pure PDMS in bacterial growth inhibition. Moreover, it was found that the antibacterial…

An ultralight Ni-MOF-rGO aerogel which possess the merits of not only broad bandwidth and strong absorption but also lightweight and thin matching thickness is fabricated through a hydrothermal treatment, freeze-drying, and annealing procedure. The Ni@C microspheres are dispersed randomly and evenly on the graphene oxide (GO) nanosheets, which can be proved through SEM and TEM results. The electromagnetic parameters of the composite can be adjusted by changing the mass ratio of the MOF and GO to endow the material with both good impedance matching and superior electromagnetic wave absorption performances. Consequently, the resulting composite shows outstanding microwave absorption performance, which achieves strong absorption (-51.19 dB) and broad effective absorption bandwidth (6.32 GHz) with a thickness of 1.9 mm while the filling content is only 2 wt %. In addition, the multiple loss mechanisms of the Ni-MOF-rGO aerogel are illustrated, including conduction loss, dipolar polarization, interfacial polarization, magnetic resonance, and eddy current loss. In a word, the…

This study investigates the mechanism behind the enhanced photocatalytic performance of carbon quantum dot (CQD)-induced photocatalysts. Red luminescent CQDs (R-CQDs) were synthesized using a microwave ultrafast synthesis strategy, exhibiting similar optical and structural properties but varying in surface functional group sites. Model photocatalysts were synthesized by combining R-CQDs with graphitic carbon nitride (CN) using a facile coupling technique, and the effects of different functionalized R-CQDs on CO 2 reduction were investigated. This coupling technique narrowed the band gap of R1-CQDs/CN, made the conduction band potentials more negative, and made photogenerated electrons and holes less likely to recombine. These improvements greatly enhanced the deoxygenation ability of the photoinduced carriers, increased light absorption of solar energy, and raised the carrier concentration, resulting in excellent stability and remarkable CO production. R1-CQDs/CN demonstrated the highest photocatalytic activity, with CO production up to 77 μmol g –1 within 4 h, which is…

A supramolecular self-assembly method was used to prepare melamine cyanurate/α-ZrP nanosheets (MCA@α-ZrP) as a novel hybrid flame retardant for thermoplastic polyurethane (TPU). Microstructure characterization showed a uniform dispersion with strong interfacial strength of the MCA@α-ZrP hybrid within the TPU matrix, leading to simultaneous enhancements in both mechanical and fire-safety properties. The TPU/MCA@α-ZrP nanocomposite exhibited 43.1 and 47.0% increments in tensile strength and fracture energy, respectively. Thanks to the platelike structure of α-ZrP coupled with the dilution effect of MCA (releasing nonflammable gases), the hybrid MCA@α-ZrP reduced the peak heat release rate of TPU by 49.7% in comparison with 15.8 and 35.4% for TPU/MCA and TPU/ α-ZrP composites, respectively. The fire performance index of TPU is significantly promoted by 90% upon adding the MCA@α-ZrP hybrid. Additionally, LOI and UL-94 tests showed high flame-retarding characteristics for the MCA@α-ZrP hybrid. For example, LOI increased from 20.0% for neat TPU to 25.5% for the MCA@α-ZrP hybrid system,…

High-efficiency electromagnetic interference (EMI) shielding and heat dissipation synergy materials with flexible, robust, and environmental stability are urgently demanded in next-generation integration electronic devices. In this work, we report the lamellar MXene/Aramid nanofiber (ANF) composite films, which establish a nacre-like structure for EMI shielding and heat dissipation by using the intermittent filtration strategy. The MXene/ANF composite film filled with 50 wt % MXene demonstrates enhanced mechanical properties with a strength of 230.5 MPa, an elongation at break of 6.2%, and a toughness of 11.8 MJ·m 3 (50 wt % MXene). These remarkable properties are attributed to the hydrogen bonding and highly oriented structure. Furthermore, due to the formation of the MXene conductive network, the MXene/ANF composite film shows an outstanding conductivity of 624.6 S/cm, an EMI shielding effectiveness (EMI SE) of 44.0 dB, and a superior specific SE value (SSE/ t ) of 18847.6 dB·cm 2 /g, which is better than the vacuum filtration film. Moreover, the MXene/ANF composite film also…

High-entropy oxide (HEO) is an emerging type of anode material for lithium-ion batteries with excellent properties, where high-concentration oxygen vacancies can effectively enhance the diffusion coefficient of lithium ions. In this study, Ni-free spinel-type HEOs ((FeCoCrMnZn) 3 O 4 and (FeCoCrMnMg) 3 O 4 ) were prepared via ball milling, and the effects of zinc and magnesium on the concentration of oxygen vacancy (O V ), lithium-ion diffusion coefficient ( D Li + ), and electrochemical performance of HEOs were investigated. Ab initio calculations show that the addition of zinc narrows down the band gap and thus improves the electrical conductivity. X-ray photoelectron spectroscopy (XPS) results show that (FeCoCrMnZn) 3 O 4 (42.7%) and (FeCoCrMnMg) 3 O 4 (42.5%) have high O V concentration. During charge/discharge, the O V concentration of (FeCoCrMnZn) 3 O 4 is higher than that of (FeCoCrMnMg) 3 O 4 . The galvanostatic intermittent titration technique (GITT) results show that the D Li + value of (FeCoCrMnZn) 3 O 4 is higher than that of (FeCoCrMnMg) 3 O 4 during charge and…

Layered double hydroxides (LDHs) are perceived as a hopeful capacitive deionization (CDI) faradic electrode for Cl – insertion due to its tunable composition, excellent anion exchange capacity, and fast redox activity. Nevertheless, the self-stacking and inferior electrical conductivity of the two-dimensional structure of LDH lead to unsatisfactory CDI performance. Herein, the three-dimensional (3D) hollow nanocage structure of CoNi-layered double hydroxide/carbon composites is well designed as a CDI anode by cation etching of the pre-carbonized ZIF-67 template. C/CoNi-LDH has a unique 3D hollow nanocage structure and abundant pore features, which can effectively suppress the self-stacking of LDH sheets and facilitate the transport of ions. Moreover, the introduced amorphous carbon layer can act as a conductive network. When employed as the CDI anode, C/CoNi-LDH exhibited a high Cl – removal capacity of 60.88 mg g –1 and a fast Cl – removal rate of 18.09 mg g –1 min –1 at 1.4 V in 1000 mg L –1 NaCl solution. The mechanism of the Cl – intercalation pseudo-capacitance reaction of…

Waterborne polyurethane has drawn extensive attention due to its environmental friendliness and is widely used in many areas. However, it is still a great challenge to synthesize waterborne polyurethanes with flame retardancy and fast room-temperature self-healing ability, along with excellent mechanical performance and emulsion stability due to the mutually contradictory nature of these properties. Herein, waterborne polyurethanes containing organic selenium (SWPU- x ) from 0.67 to 3.28 wt % were synthesized, which could simultaneously realize flame retardancy and self-healing ability based on the ability to scavenge active free radicals at high temperature and the dynamic switch of diselenide. All these SWPU- x films self-extinguished within 1 s after the ignition in the vertical combustion tests. The limiting oxygen index of SWPU-4 was improved to 28.5% with excellent UL-94 level (V-0) and self-healing efficiency (91.25%, after being healed in the photoreactor for 30 min at room temperature), together with high mechanical properties (tensile strength was 18.5 MPa and elongation…

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) offer numerous advantages, including compact size, tunable emission spectra, energy efficiency, and high integration potential. These features make them highly promising for various applications, such as night vision monitoring, food safety inspection, biomedical imaging, and theragnostics. All-inorganic halide double-perovskite materials, known for their large absorption cross section, excellent defect tolerance, and long carrier diffusion radius, serve as unique matrices for constructing near-infrared fluorescent materials. In this study, we successfully prepared the all-inorganic metal halide double-perovskite Cs 2 NaYCl 6:Cr 3+ using a grinding–sintering method. A small fraction of the [YCl 6 ] octahedra within the host material’s lattice was substituted with Cr 3+ ions, resulting in the creation of the Cs 2 NaYCl 6:Cr 3+ phosphor. When excited with λ = 310 nm UV light, the phosphor exhibited a broad emission range spanning from 800 to 1400 nm, covering the NIR-I and NIR-II regions. It had a broad bandwidth…

Magnetic tunnel junctions (MTJs) based on van der Waals (vdW) heterostructures with sharp and clean interfaces on the atomic scale are essential for the application of next-generation spintronics. However, the lack of room-temperature intrinsic ferromagnetic crystals with perpendicular magnetic anisotropy has greatly hindered the development of vertical MTJs. The discovery of room-temperature intrinsic ferromagnetic two-dimensional (2D) crystal Fe 3 GaTe 2 has solved the problem and greatly facilitated the realization of practical spintronic devices. Here, we demonstrate a room-temperature MTJ based on a Fe 3 GaTe 2 /WS 2 /Fe 3 GaTe 2 heterostructure for the first time. The tunneling magnetoresistance (TMR) ratio is up to 213% with a high spin polarization of 72% at 10 K, the highest ever reported in Fe 3 GaTe 2 -based MTJs up to now. A tunneling spin-valve signal robustly persists at room temperature (300 K) with a bias current down to 10 nA. Moreover, the spin polarization can be modulated by bias current and the TMR shows a sign reversal at a large bias current. Our work sheds…

Cost reduction and fast scale-up of electrolyzer technologies are essential for decarbonizing several crucial branches of industry. For polymer electrolyte water electrolysis, this requires a dramatic reduction of the expensive and scarce iridium-based catalyst, making its efficient utilization a key factor. The interfacial properties between the porous transport layer (PTL) and the catalyst layer (CL) are crucial for optimal catalyst utilization. Therefore, it is essential to understand the relationship between this interface and electrochemical performance. In this study, we fabricated a matrix of two-dimensional interface layers with a well-known model structure, integrating them as an additional layer between the PTL and the CL. By characterizing the performance and conducting an in-depth analysis of the overpotentials, we were able to estimate the catalyst utilization at different current densities, correlating them to the geometric properties of the model PTLs. We found that large areas of the CL become inactive at increasing current density either due to dry-out, oxygen…

Poor selectivity is a common problem faced by gas sensors. In particular, the contribution of each gas cannot be reasonably distributed when a binary mixture gas is co-adsorbed. In this paper, taking CO 2 and N 2 as an example, density functional theory is used to reveal the mechanism of selective adsorption of a transition metal (Fe, Co, Ni, and Cu)-decorated InN monolayer. The results show that Ni decoration can improve the conductivity of the InN monolayer while at the same time demonstrating an unexpected affinity for binding N 2 instead of CO 2 . Compared with the pristine InN monolayer, the adsorption energies of N 2 and CO 2 on the Ni-decorated InN are dramatically increased from −0.1 to −1.93 eV and from −0.2 to −0.66 eV, respectively. Interestingly, for the first time, the density of states demonstrates that the Ni-decorated InN monolayer achieves a single electrical response to N 2, eliminating the interference of CO 2 . Furthermore, the d-band center theory explains the advantage of Ni decorated in gas adsorption over Fe, Co, and Cu atoms. We also highlight the necessity…

The fast-growing motion capturing/monitoring technique has raised a great demand for flexible strain sensors. For capturing complex motions (e.g., facial motion), both the strain amplitude and direction should be accurately detected. Although some reported sensors based on anisotropic conductive networks are proved to show accurate localization of strain directions, it is still a great challenge to achieve both high sensitivity and a high sensing range in these designs. Here, a self-assembled Ti 3 C 2 T x MXene film with parallel and periodic wrinkles is fabricated on a stretchable poly(dimethylsiloxane) substrate for constructing multi-directional strain sensors. During stretching, relative slip and crack will occur between the stacked MXene nanosheets, which contribute to high structural sensitivity in the MXene film. Meanwhile, the wrinkled structure contributes to high stretchability. As a result, the sensor based on the film with one-dimensional periodic wrinkles shows a large sensing range (>50%) and a gauge factor of 45. Furthermore, the sensor can accurately detect both the…

Pressure sensing is highly demanding in wearable devices, robotics, and artificial intelligence, whereas it is still a big challenge to develop a pressure sensor with an excellent linear response in a broad detection range. Herein, a flexible and porous carbon nanotube (CNT)/carbon black (CB)/carbonyl iron powder (CIP)/silicone composite is proposed by a simple strategy of mixing, curing, and washing. Due to the porous structure induced by the sacrifice of sugar particles, an excellent linear response ( R 2 = 0.999) is achieved for the composite sensor by manipulating the contributions of contact resistance and tunnel resistance to the sensing performance via the alternation of CB and CNT contents. Moreover, the porous structure donates the composite sensor a low compressive modulus at a low pressure level, while the CIPs introduced lead to a high compressive modulus at a high pressure level with the assistance of an external magnetic field. As a result, the sensor produced has a wide linear response range of 80 Pa to 220 kPa, much wider than most of the linear response pressure…

Memristive devices are among the most emerging electronic elements to realize artificial synapses for neuromorphic computing (NC) applications and have potential to replace the traditional von-Neumann computing architecture in recent times. In this work, pulsed laser deposition-manufactured Ag/TiO 2 /Pt memristor devices exhibiting digital and analog switching behavior are considered for NC. The TiO 2 memristor shows excellent performance of digital resistive switching with a memory window of order ∼10 3 . Furthermore, the analog resistive switching offers multiple conductance levels supporting the development of the bioinspired synapse. A possible mechanism for digital and analog switching behavior in our device is proposed. Remarkably, essential synaptic functions such as pair-pulse facilitation, long-term potentiation (LTP), and long-term depression (LTD) are successfully realized based on the change in conductance through analog memory characteristics. Based on the LTP-LTD, a neural network simulation for the pattern recognition task using the MNIST data set is investigated,…

Tuning surface oxygen vacancies is important for oxide catalysts. Doping elements with different chemical valence states or different atomic radii into host oxides is a common method to create oxygen vacancies. However, the concentration of oxygen vacancies in oxide catalysts is still limited to the amount of foreign dopants that can be tolerated (generally less than 10% atoms). Herein, a principle of engineering the configurational entropy to tune oxygen vacancies was proposed. First, the positive relationship between the configuration entropy and the formation energy of oxygen vacancies ( E ov ) in 16 model oxides was estimated by a DFT calculation. To verify this, single binary oxides and high-entropy quinary oxides (HEOs) were prepared. Indeed, the concentration of oxygen vacancies in HEOs (O β/α = 3.66) was higher compared to those of single or binary oxides (O β/α = 0.22–0.75) by O 1s XPS, O 2 -TPD, and EPR. Interestingly, the reduction temperatures of transition metal ions in HEOs were generally lower than that in single-metal oxides by H 2 -TPR. The lower E ov of HEOs may…

Newly emerged two-dimensional transition metal carbides and/or nitrides (MXenes) have attracted considerable interest in the field of electromagnetic wave absorption, but their excessive conductivity and single loss mechanism limit their applicability. Herein, an MXene decorated with SiC NWs @Co/C was prepared by in situ growth and carbonization processes, followed by electrostatic self-assembly. The electromagnetic wave absorption performance of MXene@SiC NWs @Co/C with a bird-nest-like structure could be effectively regulated and optimized by changing the proportion of MXene and SiC NWs @Co/C. The prepared MXene@SiC NWs @Co/C hybrid absorbers reveal superior impedance matching, complementary dissipation mechanism, and plentiful heterointerfaces. Profiting from the synergy of abovementioned factors, the resultant MXene@SiC NWs @Co/C absorber exhibits an optimum reflection loss (RL) value of −76.5 dB at 6.36 GHz under a thickness of 3.9 mm and broad effective absorption bandwidth (EAB, RL ≤ −10 dB) of 6.2 GHz (11.8–18.0 GHz) with a thickness of only 2.0 mm, covering the entire Ku…

Periodontal disease is a multifactorial, bacterially induced inflammatory condition characterized by the progressive destruction of periodontal tissues. The successful nonsurgical treatment of periodontitis requires multifunctional technologies offering antibacterial therapies and promotion of bone regeneration simultaneously. For the first time, in this study, an injectable piezoelectric hydrogel (PiezoGEL) was developed after combining gelatin methacryloyl (GelMA) with biocompatible piezoelectric fillers of barium titanate (BTO) that produce electrical charges when stimulated by biomechanical vibrations (e.g., mastication, movements). We harnessed the benefits of hydrogels (injectable, light curable, conforms to pocket spaces, biocompatible) with the bioactive effects of piezoelectric charges. A thorough biomaterial characterization confirmed piezoelectric fillers’ successful integration with the hydrogel, photopolymerizability, injectability for clinical use, and electrical charge generation to enable bioactive effects (antibacterial and bone tissue regeneration). PiezoGEL showed…

Increasing the security of anticounterfeiting materials has been the most important challenge in recent years, and the development of dual-color photoluminescent inks with multi-level security, static/dynamic emission, and dynamic color change is an important solution to overcome this problem. In this study, the multi-functionalized copolymer nanoparticles containing different functional groups (with a concentration of 20 wt %), including ester, carboxylic acid, hydroxyl, epoxide, amide, and amine groups were synthesized successfully by the emulsion polymerization method. The results showed that the particle size and morphology of nanoparticles are affected by the polarity of functional groups. The prepared multi-functionalized copolymer nanoparticles were modified physically with spiropyran (photochromic and red fluorescence emission) and coumarin (cyan emission) derivatives to develop dual-color photoluminescent polymer nanoparticles with application in static-dynamic photoluminescent anticounterfeiting inks, which have multi-level security. The investigation of optical properties…

Hospital-acquired (nosocomial) infections account for the majority of adverse health effects during care delivery, placing an immense financial strain on healthcare systems around the world. For the first time, the present article provides evidence of a straightforward pollution-free technique to fabricate a heteroatom-doped carbon dot immobilized fluorescent biopolymer composite for the development of functional textiles with antioxidant and antimicrobial properties. A simple, facile, and eco-friendly approach was devised to prepare heteroatom-doped carbon dots from waste green tea and a biopolymer. The carbon dots showed an excitation-dependent emission behavior, and the XPS data unveiled that they are co-doped with nitrogen and sulfur. A facile physical compounding strategy was adopted to fabricate a carbon dot reinforced biopolymeric composite followed by immobilization onto the textile. The composite textiles revealed excellent antioxidant activity, determined by 1,1-diphenyl-2-picrylhydrazyl (>80%) and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid assays (>90%). The…

Critical-size bone defects are an important problem in clinical practice, which usually occurs in severe trauma, or tumor resection, and cannot heal completely and autonomously. Implantation of grafts is often required to promote the regeneration of critical-size bone defects. Metal ions play an important role in human health, as they affect the body’s metabolism and the tissue function. Strontium ions (Sr 2+ ) can promote osteogenesis and angiogenesis. Herein, we prepared nano-hydroxyapatite (nHA)/chitosan (CS) composite microspheres with a uniform particle size distribution and an extracellular matrix-like nanofiber structure using microfluidic technology and direct alkali-induced gelation. Strontium ions were stably added into the microspheres by using polydopamine (PDA) to chelate metal ions forming a bone repair material (nHA/CS@PDA-Sr) with good bioactivity. The coordination reaction of PDA can effectively control the release of strontium ions and avoid the negative effects caused by the high strontium concentration. Our in vitro experiments showed that the composite…

Although the application of nanozymes has been widely studied, it is still a huge challenge to develop highly active and multifunctional nanozyme catalysts with a wider application prospect. Co 3 O 4 /CoFe 2 O 4 hollow nanocubes (HNCs) with oxygen vacancies were proposed in this study, which had a porous oxide heterostructure with CoFe 2 O 4 as the core and Co 3 O 4 as the shell. The Co 3 O 4 /CoFe 2 O 4 HNCs had three enzyme activities: peroxidase-like, oxidase-like, and catalase-like. Combining XPS depth profiling with density functional theory (DFT), the catalytic mechanism of peroxidase-like activity was explored in depth, which was mainly originated from ·OH produced by the synergistic effect between the outer oxygen and inner oxygen and electron transfer between Co and Fe. A colorimetry/smartphone dual sensing platform was designed based on the peroxidase-like activity. Especially, a multifunctional intelligent sensing platform based on deep learning-YOLO v3 algorithm-assisted smartphone was constructed to realize real-time and rapid in situ detection of l -cysteine,…

Two major issues are currently hindering the clinical practice of titanium dental implants for the lack of biological activities: immediate/early loading risks and peri-implantitis. To solve these issues, it is urgent to develop multifunctional implants modified with effective osteogenic and antibacterial properties. Zinc oxide nanoparticles (ZnO NPs) possess superior antibacterial activity; however, they can rapidly release Zn 2+, causing cytotoxicity. In this study, a potential dental implant modification was creatively developed as ZnO nanoparticle-loaded mesoporous TiO 2 coatings (nZnO/MTC-Ti) via the evaporation-induced self-assembly method (EISA) and one-step spin coating. The mesoporous TiO 2 coatings (MTCs) regulated the synthesis and loading of ZnO NPs inside the nanosized pores. The synergistic effects of MTC and ZnO NPs on nZnO/MTC-Ti not only controlled the long-term steady-state release of Zn 2+ but also optimized the charge distribution on the surface. Therefore, the cytotoxicity of ZnO NPs was resolved without triggering excessive reactive oxygen species (ROS). The…

To coordinate the trade-off between the separation and permeation of the nanofiltration membrane for the separation of Mg 2+ /Li +, we regulated poly(ethyleneimine)/piperazine interface polymerization parameters to construct a positively/negatively charged ultrathin Janus nanofiltration membrane at a free aqueous–organic interface. At the optimized interfacial polymerization parameters, 0.03 wt % of piperazine reacted with trimethylbenzene chloride prior to poly(ethyleneimine), forming a primary polyamide layer with fewer defects or limiting large-scale defects of the polyamide layer. The controlled subsequent reaction of poly(ethyleneimine) and trimethylbenzene chloride results in a Janus nanofiltration membrane, with one side enriched with the carboxyl groups, the other side enriched with the amine groups, and a dense polyamide structure in the middle. Under the optimum conditions, the positive potential of the rear surface of the prepared membrane was 14.57 mV, and the water contact angle reached 71.31°, while the negative potential of the front surface was −25.48 mV, and the…

Given the inherent features of open tunnel-like structures, moderate lithiation potential (1.0–3.0 V vs Li/Li + ), and reversible redox couples (Nb 5+ /Nb 4+ and Nb 4+ /Nb 3+ redox couples), niobium-based oxides with Wadsley–Roth crystallographic shear structure are promising anode materials. However, their practical rate capability and cycling stability are still hindered by low intrinsic electronic conductivity and structural stability. Herein, ultrathin carbon-confined Nb 12 O 29 materials with rich oxygen vacancies (Nb 12 O 29– x @C) were designed and synthesized to address above-mentioned challenges. Computational simulations combined with experiments reveal that the oxygen vacancies can regulate the electronic structure to increase intrinsic electronic conductivity and reduce the Li + diffusion barrier. Meanwhile, the carbon coating can enhance structural stability and further improve the electronic conductivity of the Nb 12 O 29 material. As a result, the as-prepared Nb 12 O 29– x @C exhibits high reversible capacity (226 mAh g –1 at 0.1 A g –1 ), excellent high-rate…

It is an exigent need for the development of hydrogel dressings with desirable injectability, good adhesive, antibacterial, and wound healing promotion properties. Herein, the multifunctional injectable hydrogels with good tissue adhesion are designed based on Ag-doped Mo 2 C-derived polyoxometalate (AgPOM) nanoparticles, urea, gelatin, and tea polyphenols (TPs) for antibacterial and wound healing acceleration. After being injected into the tissue, urea diffuses out under the concentration gradient, and TPs and gelatin chains recombine to trigger the in situ formation of hydrogel with excellent adhesiveness. AgPOM fixed in the hydrogel could not only react with hydrogen peroxide in the infection site to generate singlet oxygen to kill the bacteria but also convert near-infrared light into heat under 1060 nm laser irradiation to realize sterilization. In vitro studies display the high bactericidal ability of the hydrogel against drug-resistant Staphylococcus aureus and also exhibit a prominent therapeutic effect on infected wounds through synergistic photothermal/chemodynamic therapy…

Rapid development of flexible pressure sensors is indispensable in electronic skin to have the sensing capability to static and dynamic pressures. Besides high sensitivity and low hysteresis, the high flexibility and stability of these sensors are of paramount importance owing to the application requirement of conformable pressure mapping and rugged structure. Here, we describe a novel approach for highly flexible capacitive pressure sensors with engineered stable interfaces employing PDMS-based substrates and a micropyramidal dielectric layer, Au electrodes, and molecular adhesive. The sensor/matrix stack consists of five interfaces with strong interfacial adhesion achieved using MPTMS molecular adhesive and a partially cured PDMS lamination layer. A highly flexible capacitive pressure sensor capable of a wide pressure sensing range (up to 550 kPa) is developed with a high sensitivity (46.6 MPa –1 in ≤1 kPa), capability to sense pressure as low as 27 Pa, low hysteresis (4.05%), and high stability for large pressures (11,400 cycles @ 250 kPa). The sensor is successfully demonstrated…

Stimuli-responsive hydrogels have attracted much attention over the past decade for potential bioengineering applications such as wound dressing and drug delivery. In this work, a pH and temperature dual-responsive microgel-embedded hydrogel has been fabricated by incorporating poly( N -isopropylacrylamide- co -acrylic acid) (PNIPAAm- co -AAc) based microgel particles into polyacrylamide (PAAm)/chitosan (CS) semi-interpenetrating polymer network (semi-IPN), denoted as microgel@PAM/CS. The resultant hydrogel possesses excellent mechanical properties including stretchability, compressibility, and elasticity. In addition, the microgel@PAM/CS hydrogels can tightly adhere to the surfaces of a variety of tissues such as porcine skin, kidney, intestine, liver, and heart. Moreover, it shows controlled dual-drug release profile of both bovine serum albumin (BSA) (as a model protein) and sulfamethoxazole (SMZ), an antibiotic. Excellent antimicrobial properties are obtained for SMZ-loaded microgel@PAM/CS hydrogels. Compared with traditional drug administration methods such as by mouth,…

The emergence of wide and ultrawide bandgap semiconductors has revolutionized the advancement of next-generation power, radio frequency, and opto- electronics, paving the way for chargers, renewable energy inverters, 5G base stations, satellite communications, radars, and light-emitting diodes. However, the thermal boundary resistance at semiconductor interfaces accounts for a large portion of the near-junction thermal resistance, impeding heat dissipation and becoming a bottleneck in the devices' development. Over the past two decades, many new ultrahigh thermal conductivity materials have emerged as potential substrates, and numerous novel growth, integration, and characterization techniques have emerged to improve the TBC, holding great promise for efficient cooling. At the same time, numerous simulation methods have been developed to advance the understanding and prediction of TBC. Despite these advancements, the existing literature reports are widely dispersed, presenting varying TBC results even on the same heterostructure, and there is a large gap between experiments and…

Incorporating passive radiative cooling into textiles is an effective way to improve individual personalized thermophysiological comfort for the human body. Based on radiative cooling textile design, rational functionalization further facilitates practical applications, especially for medical protective products with customized requirements. Herein, we present a hierarchical polyurethane/metal-organic framework (MOF) composite nanofiber membrane with an integrated radiative cooling effect and photocatalytic antibacterial property. Fabricated by a scalable electrospinning method, the hierarchical nanofiber membrane shows high solar reflectance of 97% and improved thermal emissivity of 93% attributed to the abundant chemical bonds in ZIF-8 nanoparticles, rendering a temperature drop of ∼7.2 °C under direct sunlight and ∼5.5 °C at night. In addition, the photocatalytic activity of ZIF-8 ensures a 96% bacterial mortality rate for preventing bacterial infection. In practical application, our composite fabric can prevent superheating by 4.4 °C compared with the traditional protective suit…

Recent advancements in wearable electronic technology demand advanced power sources to be flexible, deformable, durable, and sustainable. An ionic-solution-modified conductive hydrogel-based triboelectric nanogenerator (TENG) has advantages in wearable devices. However, fabricating a conductive hydrogel with better mechanical and electrical properties is still a challenge. Herein, a simple approach is developed to insert ion-rich pores inside the hydrogel, followed by ionic solution soaking. The suggested ionic conductive hydrogel is obtained by cross-linking the polyvinyl alcohol (PVA) hydrogel and carboxymethyl cellulose sodium salt (CMC), followed by soaking in the ionic solution. Furthermore, a flexible and shape-adaptable single-electrode TENG (S-TENG) is fabricated by combinations of ionic-solution-modified dual-cross-linked CMC/PVA hydrogel and silicone rubber. Additionally, the effects of the CMC concentration, type of ionic solution, and concentration of optimized ionic solutions on the hydrogel properties and S-TENG output performance are studied systematically. The…

Wound dressings are important for wound repair. The morphology of the biomaterials used in these dressings, and in particular, the pore structure affects tissue regeneration by facilitating attachment and proliferation of cells due to the hierarchical multiscale, water absorbance, and nutrient transport. In the present study, silk fibroin (SF) sponges with walls containing nanopores (SFNS) were prepared from SF nanoparticles generated during the autoclaving of SF solutions, followed by leaching the SF nanoparticles from the freeze-dried sponges of SF. The nano/microporous structure, biofluid absorbance, and porosity of the SF sponges with and without nanopores were characterized. In vitro cell proliferation, in vivo biocompatibility, and wound healing were evaluated with the sponges. The results demonstrated that SFNS had significantly increased porosity and water permeability, as well as cell attachment and proliferation when compared with SF sponges without the nanopores (SFS). Wound dressings were assessed in a rat skin wound model, and SFNS was superior to SFS in accelerating…

Conductive hydrogels have shown great promise in flexible electronics, but their practical applications may be impeded by the time-consuming and energy-consuming polymerization process. We proposed a sodium lignosulfonate–Fe (SLS–Fe) strategy to address this challenge and took advantage of carboxymethyl cellulose (CMC) and poly(acrylic acid) to prepare the CMC/PAA/Fe 3+ /LiCl interpenetrating conductive hydrogels with good self-healing properties, antifreezing properties, and a 6-fold increase in conductivity in this study. The hydrogel-based flexible strain sensors demonstrated a broad detection range (400%), high sensitivity (GF = 6.19 at 200–400%), and human motion detection capability. The hydrogel-based supercapacitor exhibited a single-electrode specific capacitance of 122.36 F g –1 which successfully powered LEDs. Furthermore, the supercapacitor showed a single-electrode specific capacitance of 83.16 F g –1 at −23 °C (68% of the one exhibited at 25 °C). Therefore, the multifunctional performance of the CMC/PAA/Fe 3+ /LiCl hydrogel is anticipated to play an exemplary role in a…

High Resolution Image Download MS PowerPoint Slide CO 2 is a prominent example for an exhaust gas, and it is known for its high impact on global warming. Therefore, carbon capture from CO 2 emissions of industrial processes is increasingly important to halt and prevent the disruptive consequences of global warming. Covalent organic frameworks (COFs) as porous nanomaterials have been shown to selectively adsorb CO 2 in high quantities and with high CO 2 /N 2 selectivity. Interactions with amines are recognized to selectively adsorb CO 2 and help capture it from exhaust emissions. Herein, a novel COF (Me 3 TFB-(NH 2 ) 2 BD), which was not accessible via a direct condensation reaction, was synthetized by dynamic linker exchange starting with Me 3 TFB-BD. Despite the linker exchange, the porosity of the COF was largely maintained, resulting in a high BET surface area of 1624 ± 89 m 2 /g. The CO 2 and N 2 adsorption isotherms at 273 and 295 K were studied to determine the performance in carbon capture at flue gas conditions. Me 3 TFB-(NH 2 ) 2 BD adsorbs 1.12 ± 0.26 and 0.72 ± 0.07…

High Resolution Image Download MS PowerPoint Slide Optically active luminescent materials based on lanthanide ions attract significant attention due to their unique spectroscopic properties, nonlinear optical activity, and the possibility of application as contactless sensors. Lanthanide metal-organic frameworks (Ln-MOFs) that exhibit strong second-harmonic generation (SHG) and are optically active in the NIR region are unexpectedly underrepresented. Moreover, such Ln-MOFs require ligands that are chiral and/or need multistep synthetic procedures. Here, we show that the NIR pulsed laser irradiation of the noncentrosymmetric, isostructural Ln-MOF materials (MOF-Er 3+ (1) and codoped MOF-Yb 3+ /Er 3+ (2)) that are constructed from simple, achiral organic substrates in a one-step procedure results in strong and tunable SHG activity. The SHG signals could be easily collected, exciting the materials in a broad NIR spectral range, from ≈800 to 1500 nm, resulting in the intense color of emission, observed in the entire visible spectral region. Moreover, upon excitation in the range of ≈900…

Double perovskite oxide PrBaFe 2 O 5+δ is a potential cathode material for intermediate-temperature solid oxide fuel cells. To improve its electrochemical performance, the trivalent element Ga is investigated to partially replace Fe, forming PrBaFe 2– x Ga x O 5+δ (PBFG x, x = 0.05, 0.1, and 0.15). The doping effects on physicochemical properties and electrochemical properties are analyzed regarding the phase structures, element valence states, amount of oxygen vacancies, content of oxygen species, oxygen surface exchange coefficients ( k chem ), electrochemical polarization resistance, and single-cell performance. Specifically, PBFG0.1 exhibits improved k chem, such as a 19% improvement from 4.09 × 10 –4 to 4.86 × 10 –4 cm s –1 at 750 °C, due to the increased concentration of reactive oxygen species and oxygen vacancies. Consequently, the interfacial polarization resistance is decreased by 28% from 0.057 to 0.041 Ω cm 2 at 800 °C. The subreaction steps of the oxygen reduction reaction in the PBFG0.1 cathode are further investigated, which suggests that the oxygen dissociation…

Energy-free radiative cooling is a green and ideal solution to replace air conditioning by reflecting sunlight spontaneously and radiating excess heat through atmospheric transparency windows to outer space for passive cooling. However, most radiative cooling materials are susceptible to contamination by dust, rain, etc., which reduces the cooling capacity in outdoor environments. Herein, we report on a superhydrophobic daytime radiative cooling coating based on SiO 2- coated glass bubble (SiO 2 -GB) powder that achieves strong sunlight reflectivity (96%) and high mid-infrared emissivity (98%), effectively producing an ambient temperature drop of 11.1 °C in direct outdoor sunlight. More importantly, the coating has good superhydrophobic properties with a water contact angle of 157°, which allows the coating to be self-cleaning to keep the coating free from contamination and effectively maintain good radiation cooling performance. In addition, the prepared coatings remain hydrophobic and keep good radiative cooling properties when exposed to different pH solutions and long-term…

Androgenetic alopecia (AGA) is the most common type of progressive hair loss in both men and women that severely reduces life quality and affects patients’ self-esteem. Due to the shortcomings of traditional therapeutic formulations (e.g., topical minoxidil and oral finasteride), such as low bioavailability, frequent dosing, and significant side effects, there is an urgent need to develop a safe and effective strategy for AGA treatment. Here, we report a water-soluble microneedle (MN) patch integrated with biodegradable minoxidil (MXD)-loaded microspheres for long-acting AGA treatment with reduced administration frequency and improved patient compliance. When the patch pierces the skin, the MNs rapidly dissolve and deliver MXD-encapsulated polylactic- co -glycolic acid (PLGA) microspheres into the skin, which, subsequently act as drug reservoirs for the sustained release of the therapeutics for over 2 weeks. Additionally, the application of the MN patch provided a mechanical stimulation on mouse skin, which was also helpful for hair regrowth. Compared with the topical MXD solutions…

High Resolution Image Download MS PowerPoint Slide Polymer-based nanocomposites containing inorganic ferroelectric inclusions, typically ABO 3 perovskites, have emerged as innovative dielectric materials for energy storage and electric insulation, potentially coupling the high breakdown strength (BDS) and easy processing of polymers with the enhancement of dielectric constant provided by the ferroelectric phase. In this paper, experimental data and three-dimensional finite element method (3D FEM) simulations were combined to shed some light on the effect of microstructures on the dielectric properties of poly(vinylidene fluoride) (PVDF)-BaTiO 3 composites. The existence of particle aggregates or touching particles has a strong effect on the effective dielectric constant and determines an increase of the local field in the neck region of the ferroelectric phase with a detrimental effect on the BDS. The distribution of the field and the effective permittivity are very sensitive to the specific microstructure considered. The degradation of the BDS can be overcome by coating the…

Thermal interface materials (TIMs), as typical thermal functional materials, are highly required to possess both high thermal conductivity and low Young's modulus. However, the naturally synchronized change in the thermal and mechanical properties seriously hinders the development of high-performance TIMs. To tackle such a dilemma, a strategy of codoping solid fillers and liquid metal fillers into polymer substrates is proposed in this study. This strategy includes a large amount of liquid metals that play the role of thermal paths and a small amount of uniformly dispersed solid fillers that further enhance heat conduction. Through the synergistic effect of the liquid metal and solid fillers, the thermal conductivity can be improved, and Young's modulus can be kept small simultaneously. A typical TIM with a volume of 55% gallium-based liquid metal and 15% copper particles as fillers has a thermal conductivity of 3.94 W/(m·K) and a Young's modulus of 699 kPa, which had the maximum thermomechanical performance coefficient compared with liquid metal TIMs and solid filler-doped TIMs. In…

Zero-dimensional (0D) Mn 2+ -based metal halides used as luminescent materials and scintillators have become a research hotspot in the field of photoelectric materials and devices due to their unique composition, structure, and fluorescence properties. It is of great value to explore new Mn 2+ -based metal halides to achieve multifunctional applications. Herein, the novel 0D Mn 2+ -based metal halide single crystal (BPTP) 2 MnBr 4 is synthesized by a simple solvent–antisolvent recrystallization method. Under excitation at 468 nm, the (BPTP) 2 MnBr 4 single crystal shows a pronounced narrow-band green luminescence centered at 515 nm derived from the d – d transition of the Mn 2+ ion. This emission has a relatively narrow full width at half maximum of 43 nm and a high photoluminescence quantum yield (PLQY) of 82%. In addition, (BPTP) 2 MnBr 4 exhibits good thermal stability at 393 K with a retention of 79% of the initial photoluminescence intensity at 298 K. Benefiting from its strong blue light excitation, high PLQY, and good thermal stability, we manufacture an ideal white…

Organic–inorganic metal halides (OIMHs) have abundant optical properties and potential applications, such as light-emitting diodes, displays, solar cells, and photodetectors. Herein, we report zero-dimensional Mn-based OIMH (C 8 H 20 N) 2 MnCl 4 single crystals synthesized by a simple slow evaporation method, which exhibit intense green emission at 520 nm originating from 4 T 1 – 6 A 1 transition of Mn 2+ ions. Large organic cations in the crystal structure result in the isolated [MnCl 4 ] 2– tetrahedrons, and the closest Mn–Mn distance reaches 9.07 Å, which effectively inhibits the migration of excitation energy between adjacent Mn 2+ emission centers, thus achieving a high quantum yield (∼87%) and a long photoluminescence (PL) lifetime (3.42 ms). The different optical and structural properties at low and high temperatures are revealed by temperature-dependent PL and X-ray diffraction spectra. The PL spectra and lifetimes under the heating and cooling processes indicate that the optical property transitions are reversible at 220/240 K. Our work provides a promising strategy for…

With the rapid development of Internet of Things (IoT) technology in recent years, self-actuated sensor systems without an external power supply such as flexible triboelectric nanogenerator (TENG)-based strain sensors have received wide attention due to their simple structure and self-powered active sensing properties. However, to satisfy the practical applications of human wearable biointegration, flexible TENGs impose higher requirements for establishing a balance between material flexibility and good electrical properties. In this work, the strength of the MXene/substrate interface was greatly improved by utilizing leather with a unique surface structure as the substrate material, resulting in a mechanically strong and electrically conductive MXene film. Due to the natural fiber structure of the leather surface, the surface of the MXene film with a rough structure was obtained, which improved the electrical output performance of the TENG. The electrode output voltage of MXene film on leather based on single-electrode TENG can reach 199.56 V and the maximum output power density…

With the rapid development of electronic information technology, composite materials with outstanding performance in terms of electromagnetic interference (EMI) shielding and strain sensing are crucial for next-generation smart wearable electronic devices. However, the fabrication of flexible composite films with dual functionality remains a significant challenge. Herein, multifunctional flexible composite films with exciting EMI shielding and strain sensing properties were constructed using a facile vacuum-assisted filtration process and transfer method. The films consisted of ultrathin AgNW/MXene (Ti 3 C 2 T x )/AgNW conductive networks (1 μm) attached to a flexible polydimethylsiloxane (PDMS) substrate. The obtained AgNW/MXene/PDMS composite film exhibited an exceptional EMI shielding effectiveness of 50.82 dB and good flexibility (retaining 93.67 and 90.18% of its original value after 1000 bending and stretching cycles, respectively), which are attributed to the enhanced multilayer internal reflection network created by the AgNWs and MXene as well as the synergistic effect of…

Fiber-reinforced polymer composites as a structural material have garnered tremendous interest over the past few decades. In particular, carbon fiber-reinforced epoxy (CFRE) laminates have seen extensive use in the aircraft and aerospace industry. The role of the interface between the matrix and fiber is critical and dictates the overall structural properties of the CFRE laminate. Herein, we attempt to use a commercially viable, green, and facile approach, electrophoretic deposition (EPD), to deposit covalently coupled multiscale graphene oxide (GO)/carbon nanotube (CNT) nanoconstructs onto carbon fiber (CF) fabric. The rationale behind using these hybrid conjugates is to exploit the positive synergistic effect of combining two-dimensional (2D) GO and one-dimensional (1D) CNT nanoparticles, which provide strengthening through different mechanisms resulting in a stronger matrix/fiber interface. The modified laminate with just 0.1 wt % GO/CNT content exhibited an improvement in flexural strength (FS) by 24% and interlaminar shear strength (ILSS) by 30% compared to the neat CFRE.…

Bloodstream infection (BSI) is characterized by the presence of viable microorganisms in the bloodstream and may induce systemic immune responses. Early and appropriate antibiotic usage is crucial to effectively treating BSI. However, conventional culture-based microbiological diagnostics are time-consuming and cannot provide timely bacterial identification for subsequent antimicrobial susceptibility test (AST) and clinical decision-making. To address this issue, modern microbiological diagnostics have been developed, such as surface-enhanced Raman scattering (SERS), which is a sensitive, label-free, and quick bacterial detection method measuring specific bacterial metabolites. In this study, we aim to integrate a new deep learning (DL) method, Vision Transformer (ViT), with bacterial SERS spectral analysis to build the SERS-DL model for rapid identification of Gram type, species, and resistant strains. To demonstrate the feasibility of our approach, we used 11,774 SERS spectra obtained directly from eight common bacterial species in clinical blood samples without artificial…

In recent years, two-dimensional (2D) nonlayered Bi 2 O 2 Se-based electronics and optoelectronics have drawn enormous attention owing to their high electron mobility, facile synthetic process, stability to the atmosphere, and moderate narrow band gaps. However, 2D Bi 2 O 2 Se-based photodetectors typically present large dark current, relatively slow response speed, and persistent photoconductivity effect, limiting further improvement in fast-response imaging sensors and low-consumption broadband detection. Herein, a Bi 2 O 2 Se/2H-MoTe 2 van der Waals (vdWs) heterostructure obtained from the chemical vapor deposition (CVD) approach and vertical stacking is reported. The proposed type-II staggered band alignment desirable for suppression of dark current and separation of photoinduced carriers is confirmed by density functional theory (DFT) calculations, accompanied by strong interlayer coupling and efficient built-in potential at the junction. Consequently, a stable visible (405 nm) to near-infrared (1310 nm) response capability, a self-driven prominent responsivity ( R ) of 1.24…

Flexible strain sensors have recently attracted great attention due to their promising applications in human motion detection, healthcare monitoring, human-machine interfaces, and so forth. However, traditional uniaxial strain sensors can only detect strain in a single direction. Herein, an anisotropic flexible strain sensor is fabricated based on conductive and highly aligned cellulose composite nanofibers, via facile electrospinning cellulose acetate, deacetylation, and in situ polymerization of pyrrole, to detect complex multidimensional strains. Benefiting from the unique well-ordered structure of conductive composite nanofibers, the obtained strain sensor shows extraordinary anisotropic sensing performance with a sensitivity of 0.73 and 0.01 for the tensile applied perpendicular and parallel to the nanofiber alignment, respectively. The sensor also exhibits outstanding durability (2000 cycles) due to the strong hydrogen bonding between cellulose nanofibers and polypyrrole. Moreover, the flexible strain sensors exhibit promising potentials for application in motion detection, as…

Chronic wound healing is often impaired by bacterial infection and weak trans-epithelial potential. Patches with electrical stimulation and bactericidal activity may solve this problem. However, inconvenient power and resistant antibiotics limit their application. Here, we proposed a self-powered and intrinsic bactericidal patch based on a triboelectric nanogenerator (TENG). Electrospun polymer tribo-layers and a chemical vapor-deposited polypyrrole electrode are assembled as the TENG, offering the patch excellent flexibility, breathability, and wettability. Electrical stimulations by harvesting mechanical motions and positive charges on the polypyrrole surface kill over 96% of bacteria due to their synergistic effects on cell membrane disruption. Moreover, the TENG patch promotes infected diabetic rat skin wounds to heal within 2 weeks. Cell culture and animal tests suggest that electrical stimulation enhances gene expression of growth factors for accelerated wound healing. This work provides new insights into the design of wearable and multifunctional electrotherapy devices for…

The residues of organophosphorus pesticides (OPs) have drawn worldwide increasing attention because of their potential fatal effects on human health and ecological systems. It is of great significance to develop an efficient and portable method for in-field detection of OPs. Herein, a novel core–shell nanocomposite of prussian blue@Fe-covalent organic framework@Au (PB@Fe-COF@Au) was constructed. Fe 2+ and Fe 3+ in PB nanoparticle (PBNP) cores, Fe-porphyrin in COF shells, and AuNPs grown on shells all acted as peroxidase-like catalytic active sites, enabling PB@Fe-COF@Au to possess triplet peroxidase-like activity. A colorimetric, affordable, sensitive, and selective strategy was designed to detect OPs. Compared with previous reports, this sensor realized a wider linear range for chlorpyrifos of 10–800 ng mL –1 with a relatively lower detection limit of 0.61 ng mL –1, which was attributed to the overlapping triple catalytic sites of PB@Fe-COF@Au and triple response sites to OPs. The assay was successfully employed to detect chlorpyrifos in food and environmental samples. Moreover, to…

Dual-state emitters (DSEs) are entities that exhibit fluorescence in both the solution and solid state, which open up a wide range of possibilities for their utilization in various fields. The development of detection platforms using intrinsic luminescent metal–organic frameworks (LMOFs) is highly desirable for a variety of applications. DSE MOFs as a subclass of intrinsic LMOFs are highly attractive due to no need for encapsulation/functionalization by fluorophores and/or using luminescent linkers. Herein, a highly stable intrinsic dual-state blue emission (λ em = 425 nm) zinc-based MOF with rodlike nanostructures (denoted as UoZ-2) was synthesized and characterized. To the best of our knowledge, intrinsic DSE of Zn-MOFs with blue emission in the dispersed form in solution and solid-state fluorescence have not been reported yet. When tetracycline (TC) was added, a continuous color evolution from blue to greenish-yellow with dramatic enhancement was observed due to aggregation induced emission (AIE). Thus, a sensitive ratiometry-based visual detection platform, in solution and on…

Transmission near-infrared (NIR) imaging technology has great potential for biomedical imaging because of its lower water absorption coefficient and highly reduced photon scattering effect in biological tissues compared to visible light. The extent of biological tissue photon scattering is inversely proportional to wavelength; therefore, in principle, imaging with long-wavelength NIR helps improve the resolution of the optical image, but deep tissue high-resolution luminescence imaging is still very challenging technically. Here, we report the discovery of a Ba 2 MgWO 6:Ni 2+ double perovskite phosphor that emits broadband long-wavelength NIR (1200–2000 nm) under 365 nm near-ultraviolet (UV) excitation, with a full width at half-maximum of 255 nm. The luminescence quantum efficiency of the phosphor with optimized composition reached 16.67%. The analysis of the crystal structure of Ba 2 MgWO 6:Ni 2+ suggests that Ni 2+ ions preferentially occupy the W 6+ site in octahedrons with a weak crystal field, which leads to a large Stokes shift. An as-prepared long-wavelength NIR pc-LED…

Self-powered photodetectors have triggered widespread attention because of the requirement of Internet of Things (IoT) application and low power consumption. However, it is challenging to simultaneously implement miniaturization, high quantum efficiency, and multifunctionalization. Here, we report a high-efficiency and polarization-sensitive photodetector enabled by two-dimensional (2D) WSe 2 /Ta 2 NiSe 5 /WSe 2 van der Waals (vdW) dual heterojunctions (DHJ) along with a sandwich-like electrode pair. On account of enhanced light collection efficiency and two opposite built-in electric fields at the hetero-interfaces, the DHJ device achieves not only a broadband spectral response of 400–1550 nm but outstanding performance under 635 nm light illumination including an ultrahigh external quantum efficiency (EQE) of 85.5%, a pronounced power conversion efficiency (PCE) of 1.9%, and a fast response speed of 420/640 μs, which is much better than that of the WSe 2 /Ta 2 NiSe 5 single heterojunction (SHJ). Significantly, based on the strong in-plane anisotropy of 2D Ta 2 NiSe 5 nanosheets,…

Antibacterial conductive hydrogels have been extensively utilized in tissue repair and regeneration on account of their unique electrochemical performances and advantages of anti-pathogenic bacterial infection. Here, multi-functional collagen-based hydrogels (CHLY) with adhesivity, conductivity, and antibacterial and antioxidant activities were developed by introducing cysteine-modified ε-poly(l-lysine) (ε-PL-SH) and in situ-polymerized polypyrrole (PPy) nanoparticles to induce full-thickness wound healing. CHLY hydrogels have a low swelling ratio, good compressive strength, and viscoelasticity due to chemical crosslinking, chelation, physical interaction, and nano-reinforcements in the matrix network of hydrogels. CHLY hydrogels possess excellent tissue adhesion ability, low cytotoxicity, enhanced cell migration ability, and good blood coagulation performance without causing hemolysis. Interestingly, the chemical conjugation of ε-PL-SH in the hydrogel matrix gives hydrogels an inherently robust and broad-spectrum antibacterial activity, while the introduction of PPy endows…

Lithium-ion batteries (LIBs) have achieved a triumph in the market of portable electronic devices since their commercialization in the 1990s due to their high energy density. However, safety issue originating from the flammable, volatile, and toxic organic liquid electrolytes remains a long-standing problem to be solved. Alternatively, composite solid electrolytes (CSEs) have gradually become one of the most promising candidates due to their higher safety and stable electrochemical performance. However, the uniform dispersity of ceramic filler within the polymer matrix remains to be addressed. Generally, all-solid-state lithium metal batteries without any liquid components suffer from poor interfacial contact and low ionic conductivity, which seriously affect the electrochemical performance. Here we report a CSE consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), polydopamine (PDA) coated Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) (denoted as PDA@LLZTO) microfiller, polyacrylonitrile (PAN), and poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP). Introducing…

Along with hypoxia, severe bacterial infection, and abnormal pH, continuous inflammatory response hinders diabetic wounds from healing. It leads to the accumulation of large amounts of reactive oxygen species (ROS) and therefore prevents the transition of diabetic wounds from the inflammatory phase to the proliferative phase. In this work, a nanohybrid double network hydrogel with injectable, self-healing, and tissue adhesion properties based on a platinum nanozyme composite (PFOB@PLGA@Pt) was constructed to manage diabetic wound healing. PFOB@PLGA@Pt exhibited oxygen supply capacity and enzyme catalytic performance accompanied by pH self-regulation in the entire phases of wound healing. In the first stage, the oxygen carried by perfluorooctyl bromide (PFOB) can ameliorate the hypoxia and boost the glucose oxidase-like catalyzed reaction of Pt NPs, leading to a lowered pH environment with gluconic acid. As a result, the NADH oxidase-like, peroxidase-like, and oxidase-like multiple enzyme activities were activated successively, leading to synergistic antibacterial effects through the…

New conductive materials for tissue engineering are needed for the development of regenerative strategies for nervous, muscular, and heart tissues. Polycaprolactone (PCL) is used to obtain biocompatible and biodegradable nanofiber scaffolds by electrospinning. MXenes, a large class of biocompatible 2D nanomaterials, can make polymer scaffolds conductive and hydrophilic. However, an understanding of how their physical properties affect potential biomedical applications is still lacking. We immobilized Ti 3 C 2 T x MXene in several layers on the electrospun PCL membranes and used positron annihilation analysis combined with other techniques to elucidate the defect structure and porosity of nanofiber scaffolds. The polymer base was characterized by the presence of nanopores. The MXene surface layers had abundant vacancies at temperatures of 305–355 K, and a voltage resonance at 8 × 10 4 Hz with the relaxation time of 6.5 × 10 6 s was found in the 20–355 K temperature interval. The appearance of a long-lived component of the positron lifetime was observed, which was dependent on the…

The compelling integration of superhydrophobic coatings with light-to-heat conversion capabilities has garnered substantial interest due to their dual functionality encompassing passive anti-icing and deicing attributes. However, the insufficient mechanical stability and the environmental and human health concerns stemming from the extensive use of organic solvents limit their practical application. In this study, an all-waterborne superhydrophobic photothermal coating (PCPAS) was prepared through the synergy of composite micro–nanoparticles derived from carbon nanotubes (CNT), polydopamine (PDA), and Ag particles with fluorine-containing polyacrylic emulsion (PFA). The PDA provided active sites for Ag + reduction reaction and enhanced the interfacial interaction between CNT and Ag particles. The interfacial enhancement enabled the coating to maintain stable superhydrophobicity after 260 times sandpaper abrasion and 240 times tape peeling. Simultaneously, the composite micro–nanoparticle’s light-to-heat conversion ability gave the coating excellent anti-icing/deicing capabilities.…

Implant-associated infection (IAI) caused by pathogens colonizing on the implant surface is a serious issue in the trauma-orthopedic surgery, which often leads to implant failure. The complications of IAI bring a big threat to the clinical practice of implants, accompanied by significant economic cost and long hospitalization time. In this study, we propose an antibiotics-free strategy to address IAI-related challenges by using a biodegradable and cytocompatible hydrogel coating. To achieve this, a novel hydrogel system was developed to combine the synergistic effects of good cell affinity and antibacterial properties. The hydrogel material was prepared by modifying a photocross-linkable gelatin-based polymer (GelMA) with cationic quaternary ammonium salt (QAS) groups via a mild and simple synthesis procedure. By engineering the length of the hydrophobic carbon chain on the QAS group and the degree of functionalization, the resulting GelMA-octylQAS hydrogel exhibited an integration of good mechanical properties, biodegradability, excellent bactericidal activity against various types…

Scintillators enable invisible X-ray to be converted into ultraviolet (UV)/visible light that can be collected using a sensor array and is the core component of the X-ray imaging system. However, combining the excellent properties of high light output, high spatial resolution, flexibility, non-toxicity, and cost effectiveness into a single X-ray scintillator remains a great challenge. Herein, a novel scintillator based on benzyltriphenylphosphonium manganese(II) bromide (BTP 2 MnBr 4 ) nanocrystal (NC) membranes was developed by the in situ fabrication strategy. The long Mn–Mn distance provided by the large BTP cation allows the nonradiative energy dissipation in this manganese(II) halide to be significantly suppressed. As a result, the flexible BTP 2 MnBr 4 NC scintillator shows an excellent linear response to the X-ray dose rate, a high light yield of ∼71,000 photon/MeV, a low detection limit of 86.2 nGy air /s at a signal-to-noise ratio of 3, a strong radiation hardness, and a long-term thermal stability. Thanks to the low Rayleigh scattering associated with the dense…