With rapid advances in nanotechnology and materials science, the development of high-performance humidity sensors has become a research hotspot. In this work, the porous carbon nanofibers (PCNFs) with controllable nanopore structure were prepared from polyacrylonitrile (PAN)/poly(vinylidene fluoride) (PVDF) blended polymers by electrospinning technique and carbonization method. The low-cost and easily available PCNFs were introduced into the polyvinyl alcohol (PVA) humidity-sensitive system, and the PVA/PCNFs composite nanofibrous humidity-sensitive layer was fabricated on the surface of quartz crystal microbalance (QCM) sensors. The PVA/PCNFs composite nanofiber-modified QCM moisture-sensitive element had good moisture-sensitive response characteristics with a maximum frequency response of -3114 Hz (11%-98% RH), a fitted correlation coefficient of R-2 = 0.9981, and response/recovery times of 36 s/< 1 s and 60 s/< 1 s under low and high humidity conditions, respectively. In addition, the QCM sensor based on PVA/PCNFs nanofibers showed good reproducibility and long-term stability. Compared with other moisture-sensitive elements, the PVA/PCNFs moisture-sensitive element has the characteristics of fast response and easy fabrication, which provides a solution for the preparation of low-cost, high-performance and environmentally friendly moisture-sensitive elements.

SnCl2 & centerdot;2H(2)O was introduced into polyacrylonitrile (PAN) nanofibers through a simple electrospinning method, and composite Sn nanoparticle-carbonized (Sn@C) nanofibers were prepared by two-stage calcination. After dispersing different amounts of composite nanofibers in a 2.5 wt% chitosan (CS) solution via ultrasonication, a series of CS/Sn@C composite humidity-sensitive layers were spin-coated on quartz crystal microbalance (QCM) sensor surfaces. The morphology, structure, and composition of Sn@C nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption isotherm analysis combined with the Brunauer-Emmett-Teller (BET) method. The diameter of Sn@C nanofibers decreased from 180 nm to 95 nm upon decreasing the PAN content from 90% to 60%. The presence of metallic Sn nanoparticles, formed on the surface of Sn@C nanofibers, resulted in an increase in specific surface area from 5.1 m & sup2;& centerdot;g(-)& sup1; to 106.5 m & sup2;& centerdot;g(-)& sup1; . Using an electrospinning solution with PAN:SnCl2 & centerdot;2H(2)O (8:2 w/w) and a Sn@C dispersion (0.05 mg/mL) in 2.5 wt% CS solution, a QCM sensor with a fitting correlation coefficient of 0.9998 was fabricated. The sensor parameters were optimized through QCM testing under varying conditions. The sensor demonstrated fast response/recovery times: < 1.2 s (response)/50 s (recovery) in 11-33% RH and 67 s/37 s in 11-98% RH. Additionally, the CS/Sn@C-modified QCM sensor exhibited high repeatability, reversibility, and low humidity hysteresis.

Conductive hydrogels have attracted significant interest due to their potential applications in human motion monitoring, health diagnostics, and beyond. However, integrating ultra-stretchability, strain sensitivity, and freeze resistance into hydrogel strain sensors remains a challenge. In this study, polyacrylamide/polyvinyl alcohol/quaternized chitosan (PAM/PVA/QCS, PPQ) hydrogel was fabricated via a one-pot in situ free radical copolymerization process, followed by freeze-thaw treatment and immersion. The hydrogel matrix consists of acrylamide (AAm) chemically crosslinked by N, N '-methylenebisacrylamide (MBA) and PVA, forming a physically crosslinked hydrogen-bonded network, with QCS serving as the reinforcing phase. Under the Hofmeister effect, introduction of citrate ions (Cit3-) as salting-out ions facilitates hydrogen bond formation through amino groups (-NH2) in PAM, while establishing electrostatic interactions with the quaternary ammonium groups in QCS. Concurrently, Cit3- anions regulate the hydration chemistry of PVA by adsorbing water molecules within the polymer chains. The ionic hydrogel demonstrates a maximum elongation of 1,014% and ionic conductivity of 1.43 S/m while maintaining stable performance at -20 degrees C. It exhibits exceptional mechanical properties, frost resistance, and electrical conductivity. Notably, when deployed as a flexible strain sensor, the hydrogel achieves outstanding tensile strain sensitivity (GF = 1.812), rapid response, and stable electrical signal output over 500 cyclic loading-unloading tests.

Adsorption technology plays a vital role in addressing water pollution issues stemming from dyes. Adsorption materials are the key, yet conventional graphene-based adsorbents are constrained by multi-step synthesis, high energy demand, and the use of hazardous etchants. In this study, a straightforward, swift, and eco-friendly laser-induced method is employed to transform commercially available polystyrene and ferroferric oxide into core-shell structured graphene magnetic adsorbents. Graphene provides abundant porous structures and surface adsorption sites, while ferroferric oxide provides magnetic functions. This magnetic adsorbent exhibits excellent adsorption performance for methylene blue solutions, with a saturated adsorption capacity of up to 156 mg/g and good recycling stability. Its adsorption behavior conforms to the pseudo-second-order kinetic model, indicating that chemical adsorption dominates the process, which is mainly synergistically driven by electrostatic attraction, pi-pi stacking interaction, and hydrogen bonding. The isothermal adsorption data fit the Langmuir model, revealing that it is dominated by uniform monolayer adsorption. This approach not only transcends the constraints of conventional polymer carbonization techniques but also successfully engineers a recyclable system for adsorption and recovery grounded on such methodology. The research also elucidates the mechanism behind polymer in-situ carbonization under laser irradiation, offering a novel approach to the treatment of dye-contaminated wastewater.

With the rapid development of wearable electronic devices and flexible energy storage devices, planar micro-supercapacitors (MSCs) have attracted great attention as a new type of energy storage devices in industrial applications and scientific research. However, the complex fabrication process, weak substrate stability, and low specific capacitance of MSCs hinder their widespread application. In this work, we proposed a simple laser-induced graphene (LIG) to create rectangular electrode patterns on polyimide (PI) film substrate, succeeding in fabricating high-performance flexible planar MSCs. This approach offers a more convenient process flow and lower fabrication costs. Surprisingly, the MSCs exhibit good cycling characteristics and durability, with the area ratio of supercapacitors up to 25.18 mF cm-2 at a current density of 0.1 mA cm-2. Furthermore, with increased energy density, the complex of supercapacitor devices was able to light a square alarm clock for about two minutes. Thanks to the high specific surface area and high conductivity of the unique crystal structure, the MSCs exhibit great potential applications in electronic information, flexible electronics, storage energy and other fields.

Hydrogel-based functional materials have garnered widespread attentions across various fields due to their unique three-dimensional network microstructure and versatile, tunable properties. However, owing to the absence of a systematic analysis of the application mechanisms of hydrogels in diverse fields, accurately choosing the suitable type of hydrogel and its preparation method for specific application scenarios still presents challenges. This review explores the latest advances and continuing challenges for hydrogel-based functional materials, covering a variety of preparation methods, including chemical cross-linking, physical cross-linking, and radiation cross-linking, and applications in different fields, such as separation processing, agriculture, smart device, and biomedical engineering. Furthermore, the future research directions of hydrogel-based functional materials are outlined, which may focus on the development of environmentally friendly hydrogel materials, the study of high-precision and high-sensitivity hydrogels, and the in-depth exploration of the interaction mechanisms between hydrogels and biological systems. This review aims to provide comprehensive theoretical references and technical insights for the development of innovative hydrogel materials with more potential applications.

As an important packaging material, linear low-density polyethylene (LLDPE) faces a key industrial bottleneck: producing clear, high-contrast permanent laser markings on its surface. Existing studies adopt laser-sensitive fillers including carbon black, carbon nanotubes and metal oxides like Bi2O3 and ZnO to improve polymer laser sensitivity, yet these substances bring dust risks and biological toxicity. Herein, non-toxic titanium dioxide (TiO2) is used as laser-sensitive additive. Uniformly dispersed TiO2 converts laser energy into heat through photothermal effect, inducing localized LLDPE carbonization to form adjustable high-contrast black marks. Optimal marking parameters (12 W, 1000 mm/s, 0.5 wt

A coating of polyacrylonitrile (PAN) nanofibers was prepared onto gold-coated quartz crystal microbalance (QCM) sensors using an electrospinning method. Different deposition amounts of these nanofibers were obtained by controlling the deposition time. Subsequently, chitosan (CS) was spin coated onto these modified QCM sensors to obtain coatings of CS-PAN composite nanofibers. The resulting construct was employed as a QCM humidity sensor. Scanning electron microscopy (SEM), atomic force microscopy (AFM), laser scanning confocal microscopy (LSCM), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize CS-PAN composite nanofibers in terms of their surface structure, morphology, roughness, dispersion, and composition. The humidity sensing characteristics of the CS-PAN composite nanofibers were studied in detail by QCM. The CS-PAN composite nanofiber modified QCM sensor responds strongly and reversibly to humidity, with a maximum frequency response of -1470 Hz (11-98 % RH), a high fitting correlation coefficient (R-2 = 0.9998), and a fast response/ recovery time of < 4 s/33 s and 21 s/63 s at low and high humidity level, respectively. In addition, the QCM sensor based on CS-PAN nanofibers show high selectivity, high repeatability and long-term stability. The twostep electrospin/spin-coating fabrication of the high-correlation CS-PAN humidity sensor is not only facile and cost effective, but also versatile in terms of nanofiber functionalization.

A self‐healing polyurethane elastomer (IPDA 0.5 ‐PPGTD 1.0 ‐Urea 0.5 ) with good mechanical properties is prepared by changing the dynamic properties and hydrogen bond density of the hard segment units through a facile one‐pot poly‐condensation approach. Comprehensive characterization techniques are utilized to analyze the structure, performance, and self‐healing mechanism of IPDA 0.5 ‐PPGTD 1.0 ‐Urea 0.5 . The findings reveal that the amorphous structure of the polymer network, coupled with the rapid dissociation–reassociation dynamics of hydrogen bonds and the inherent mobility of hard segment units, imparted IPDA 0.5 ‐PPGTD 1.0 ‐Urea 0.5 with exceptional mechanical properties, including a tensile strength of 1.92 MPa and an elongation at break exceeding 1600%. Notably, the mechanical performance achieves complete recovery within 12 h, accompanied by outstanding puncture and tear resistance. The types of hydrogen bonds in hard phase units are studied by two‐dimensional correlation Fourier‐transform infrared spectra, the dynamics of hydrogen bonds are investigated by variable‐temperature infrared and the dynamics of polymer chain segments are investigated by Arrhenius equation. Due to its excellent mechanical properties and self‐healing properties, IPDA 0.5 ‐PPGTD 1.0 ‐Urea 0.5 shows excellent application potential in self‐healing flexible conductors.

Transparent polymer films face critical limitations in dynamic information encryption, including irreversible transparency loss, simplistic encrypted patterns, and the absence of active security mechanisms. To overcome these, this study proposes a laser-programming strategy using polyvinyl alcohol composites synergistically doped with carbon nanotubes (50 ppm) and glucose monohydrate (4 wt%). This system maintains > 60% transmittance while enabling cross-dimensional structural and chromatic responses: low-energy irradiation induces 2D translucent whitening via grain-boundary scattering (Delta E = 3.04-14.96); medium energy triggers milky-white 3D foaming with 1162 mu m height differential; high energy drives gradient carbonization (from charred yellow to brown, Delta E = 26.66-42.98). Leveraging precise energy-threshold control, this study develops dual encryption paradigms: 1) Hydro-triggered concealment/laser decryption enables water-driven reversible erasure (>95% transmittance recovery) with selective background whitening for "opaque-background/transparent-message" revelation; 2) Dual-laser-threshold encryption combines sub-threshold invisible writing (<5% transmittance variation) and localized foaming/carbonization development. Both integrate auto-destruct security, where supra-critical energy irreversibly destroys data. The film exhibits exceptional stability (abrasion/bending/aging resistance) and dynamic optical/tactile feedback, providing mask-free single-step fabrication of high-security anti-counterfeiting features that bridge transparent-substrate encryption from concept to practical applications.

Solar-driven interfacial water evaporation technology offers a green solution for sustainable seawater desalination and wastewater treatment. However, existing materials face challenges such as low photothermal conversion efficiency, performance degradation due to salt accumulation, and high-cost fabrication processes. This study developed a bilayer solar evaporator based on laser-irradiated graphene oxide (GO) coatings and natural bamboo, achieving efficient, stable, and low-cost desalination and wastewater purification. Through one-step laser irradiation, GO coatings were simultaneously reduced, porosified, and functionalized, forming an evaporation interface with high photothermal conversion efficiency and hierarchical mesoporous structures. Integrated with bamboo's vertically aligned microchannels, the device enabled synergistic water transport-evaporation, delivering an evaporation rate of 2.03 kgm(-)(2)h(-)(1) under 1 sun intensity. It maintained a stable rate of 1.5 kgm(-)(2)h(-)(1) during prolonged seawater desalination, demonstrating exceptional salt resistance. Additionally, the evaporator exhibited outstanding purification capabilities (>99.8 %) for dye- and metal-laden wastewater. Notably, the device can be scaled up by adjusting the number of bamboo units and maintains stable performance during prolonged outdoor water evaporation experiments. Compared to conventional biomass-based evaporators, this work provides a novel strategy for designing high-performance solar evaporators with superior efficiency, cost-effectiveness, and simplicity, paving the way for practical applications in sustainable water purification.

Metal powder injection molding (MIM) has been a popular technique in production of alloy materials. Through this technique, near-net-shape alloy products can be molded with one-step production. Stainless steel 316 L (SS 316 L) is an important material in aerospace and marine industry for its excellent material strength and resistance to corrosion. As the industry grows with upgraded techniques, the standard for next generation material strength has improved tremendously. Here we present a practical method strengthening SS 316 L via MIM technique, which might provide a pathway for exploration of high strength materials. TiC was introduced into SS 316 matrix with polyoxymethylene (POM) binder. The metallography indicates that the introduction of TiC facilitates the refinement of the 316 L grain. As the TiC content increases from 0 wt% to 3 wt%, the material properties improve significantly, including a rise in hardness from 151 HV to 301 HV, tensile strength from 689 MPa to 792 MPa, and yield strength from 221 MPa to 339 MPa. Additionally, there is a noticeable reduction in the coefficient of friction and the wear cross-section.

Solar seawater evaporation is a sustainable seawater desalination technology. However, how to convert low‐cost waste general plastics into highly efficient photothermal materials remains a challenge. By using the idea of “near‐infrared laser‐induced carbonization” at room temperature and in air atmosphere, polystyrene (PS) can be easily converted into graphene. Bismuth oxide (Bi 2 O 3 ) catalyst is proven to efficiently convert laser energy into thermal energy and transmit it to the surrounding PS matrix, promoting carbonization. On this basis, by adjusting the catalyst content and the laser energy density per unit area, laser‐induced graphene (LIG) materials with high specific surface area, fast water transport, and high solar energy absorption efficiency can be obtained. Furthermore, the LIG materials are coated on the surface of natural bamboo with a capillary structure. This bilayer evaporation device has an evaporation rate of 1.51 kg m −2 h −1 and an energy conversion efficiency of 87.1% under irradiation of 1 sun. This work not only reveals the possibility of preparing high‐value‐added graphene materials from waste general‐purpose plastics, but also proves the application prospects of LIG materials in the field of solar seawater evaporation. This will provide a feasible approach for promoting the development of carbonization of waste general plastics.

Solar water evaporation technology is of great significance in alleviating the problem of clean water shortage. However, interface evaporation materials are crucial for solar evaporator and are hindered by high costs, complex processes, and environmental issues. In this work, a simple, fast, and environmentally friendly laserinduced carbonization strategy was used to convert commercial polypropylene into porous carbon materials in a one-step process, and assembled with natural bamboo to form an efficient dual-layer evaporator. The residual carbon nanotubes catalyst in the carbonized products further enhance its evaporation performance. The water evaporation rate of the evaporator under one sun is 1.93 kg center dot m- 2 center dot h- 1 . In addition, the evaporator has an evaporation rate of 1.62 to 1.85 kg center dot m- 2 center dot h- 1 for wastewater containing methylene blue, carmine, CuCl 2 and FeCl 3 . This strategy not only overcomes the limitations of traditional polymer carbonization methods but also allows for size adjustment based on the quantity of bamboo, and has been successfully applied to wastewater evaporation experiments under cold outdoor weather conditions. The proposed strategy not only elucidates the carbonization mechanism of polymers under laser irradiation, but also provides a new approach for the field of solar water evaporation.

Currently, the use of metal-organic framework (MOF)-based peroxidase (POD) mimics has been attempted for the development of colorimetric biothiol detection sensors. Furthermore, Ni/Co layered double hydroxides (NiCo-LDH), as sourced from MOF, have attracted increasing interest as enzyme mimics for colorimetric detection due to their low cost, adjustable layered structure, and composition. Herein, the hollow cubes of NiCo-LDH were synthesized with zeolitic imidazolate framework-67 (ZIF-67) as a sacrificial template. NiCo-LDH nanosheets were used to construct the hollow cubes with additional active sites exposed by the hollow structure. A series of experiments were conducted to confirm the superior catalytic activities of NiCo-LDH nanozymes as peroxidase (POD)-like inhibitors to horseradish peroxidase. The enzymatic kinetic constant Km values for NiCo-LDH nanozyme were 0.70 mM (H2O2) and 0.16 mM (TMB). Glutathione (GSH) was determined with a detection limit of 0.263 mu M and a detection range from 5 to 60 mu M. Meanwhile, the platform exhibited exceptional selectivity and stability. The mechanism and application of NiCo-LDH nanozymes were explored to promote the development of nanozymes with multi-metal active sites.

Hydrogen production via electrocatalytic water splitting is generally considered as an efficient and eco-friendly strategy for energy storage. The exploration of novel electrocatalytic cathode material towards hydrogen evolution reaction (HER) has never ended. Laser induced graphene (LIG), as a cheap and porous material with large surface area, not only can be used as a carrier of active substances for collaborative catalysis towards hydrogen evolution, but also can be directly used as catalytic electrode via heteroatoms doping. We synthesized Fe _3 O _4 embedded LIG via laser ablation of polyimide (PI)/Fe(acac) _3 film and tested its HER electrocatalytic performance. An overpotential of 269 mV was obtained under the current density of 10 mA cm ^−2 with a slight current decay in the 10 h chronoamperometric examination in 1 M KOH electrolyte. This work provides an insight into methods of optimizing electrochemical properties and improving catalytic activity of LIG based materials. The performance of our Fe _3 O _4 embedded LIG demonstrates the potential of LIG based materials as next generation HER electrocatalyst.

VOCs has serious impacts on the environment and humans due to its volatility. Activated carbon, as an adsorption material, has a rich pore structure and is widely used. This study uses fast-growing bamboo as a precursor and water vapor as a high-temperature activating agent to prepare environmentally friendly and green activated carbon adsorbent materials with high specific surface area and high adsorption performance. Microscopic observations show that natural bamboo has a regular porous fiber structure, which is conducive to the penetration of water vapor and the occurrence of activation reactions at high temperatures. BET tests show that the activation temperature has a significant impact on the specific surface area and pore size distribution of the final activated carbon product. When the activation temperature is 850 o C, the specific surface area can reach up to 1315 m²/g, and it exhibits high VOCs adsorption capacity and cyclic adsorption performance. This study provides a new approach for the environmentally friendly preparation of biomass carbon materials and expands the application prospects of carbon materials in the field of adsorption.

As the global epidemic eases today (2023), the high economic and environmental costs brought about by excessive production of masks are further disrupting global society. This study explores a unique approach to endow common commercial surgical masks with efficient volatile organic compounds (VOCs) adsorption properties as well as recyclability. A near-infrared laser irradiation method was developed for the formation of laser-induced porous graphene oxide coating on polypropylene masks. Graphene oxide coating can absorb laser energy and "explode", thus realizing the transition from smooth coating to porous coating. This mask with porous graphene oxide coating can be directly used as an excellent VOCs filter material. The laser irradiation process in the air environment endows the porous coating with rich oxygen-containing groups, which makes the mask highly hydrophilic and breathable. In addition, the excellent absorbance of graphene oxide coating enables it to rapidly heat up under solar, allowing the mask to be desorbed and reused. Compared to traditional powder spraying methods, the coating of porous graphene oxide is more stable as a whole. This method can not only solve the problem of excess masks after the epidemic, but also provide a new idea for wearable protective textiles for VOCs.

The patterning of transparent PET film plays an indispensable role in the application of packaging materials. However, traditional processes such as ink printing limit the pattern to a 2D plane. Recently, laser irradiation technology has been demonstrated as a potential strategy for achieving surface patterning of polymer materials. Here, we found that metallic oxide substrate can absorb laser energy and transfer it to transparent PET film through the interface, thereby improving the absorption of laser by PET. The preparation process of metallic oxide substrate is low-cost, scalable, and easy to prepare. Irradiation experiments were conducted at different energy densities, and the results show that the laser-induced patterns on the surface of PET film can be arbitrarily transformed between 2D and 3D. The PET film absorbs a large amount of heat through the interface with the substrate, which is the main factor regulating the pattern morphology. In addition, the controllability of photothermal conversion between interfaces enables laser-induced patterns to be designed locally and arbitrarily, thus achieving practical applications. The present method may open a new avenue for the application of laser patterning and meet the extensive requirements of transparent polymer materials in the fields related to surface 2D/3D pattern design.

The composite microgels were synthesized from N-Isopropylacrylamide (NIPAM) and acrylic acid (AA) monomers in the presence of graphene oxide (GO) using an in situ radical copolymerization method. The successful preparation of these composite microgels was investigated through Fourier transform infrared spectroscopy (FTIR), ultraviolet visible absorption spectroscopy (UV-vis), and Raman spectroscopy. Due to the hydrophilic properties of GO and the microgels containing oxygenated groups (-OH, -COOH, and -CONH2), quartz crystal microbalance (QCM) sensors can be fabricated by spraying the GO/P(NIPAM-co-AA) dispersion onto QCM sensors as sensitive coating materials. The results indicate a notable enhancement in the performance of GO/P(NIPAM-co-AA) modified QCM humidity sensor, compared to QCM sensors modified with either GO or P(NIPAM-co-AA) microgels alone. This improvement is mainly evidenced by higher sensitivity and reduced moisture hysteresis. The humidity sensing mechanism is based on the combined effect of GO and P(NIPAM-co-AA) microgels, which synergistically enhance the sensor's performance. Additionally, the results from water contact angle measurements, laser scanning confocal microscopy (LSCM), and scanning electron microscope (SEM) show that GO/P(NIPAM-co-AA) exhibits greater roughness and stronger hydrophilicity than either GO or P(NIPAM-co-AA) microgels alone. These properties make GO/P(NIPAM-co-AA) an effective moisture-sensitive material for QCM sensors.