Synergistic Stain Removal Achieved by Controlling the Fractions of Light and Thermo Responsive Components in the Dual-Responsive Copolymer Immobilized on Cotton Fabrics by Cross-Linker

Ionic Liquid Modification of Acidic Dyes for Impermeable Inkjet Printing on Untreated Polyamide Fabrics

This study introduces a novel approach to inkjet printing on untreated polyamide fabrics (Nylon-66), leveraging the power of ionic liquids to enhance acid dye performance. By replacing sodium ions in Acid Big Red G and Acid Carmine dyes with 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), ink impermeability and dye-fiber bonding on nonpretreated fabric were improved significant on unpretested Nylon-66. The modified inks demonstrate reductions in line widths (24.75% for Dye G and 33.95% for Dye R) and substantial increases in K/S values (43.24% and 24.83%, respectively), while maintaining consistent CIE color coordinates. The innovation lies in the superior performance of imidazolium cations over traditional sodium ions, resulting in enhanced ionic bonding and reduced ink bleeding. This discovery is attributed to the larger ionic radius and increased positive charge density of the ionic liquid, facilitating stronger interactions with polyamide fibers. Crucially, the method eliminates the need for fabric pretreatment, simplifying the printing process and significantly reducing environmental impact by minimizing wastewater generation. This innovation not only advances digital inkjet printing technology but also offers a more sustainable and efficient solution for high-quality textile printing without compromising color vibrancy.

Harnessing photo-responsive azobenzene-functionalized chitosan nanomicelles for UV protection of photosensitive pesticides

Photosensitive pesticides are susceptible to ultraviolet (UV) light, leading to their easy photodegradation and short half-life under natural conditions. In this context, it is highly desired to develop novel pesticide formulations with UV protection efficiency. In this study, a photo-responsive amphiphilic chitosan-based copolymer (mPEG-CS-AZO) was synthesized successfully by the grafting of poly(ethylene glycol) as the hydrophilic chains, and azobenzene moieties that serve as both hydrophobic and photo-responsive constituents. The mPEG-CS-AZO was characterized with 1H NMR, FTIR, and the critical micelle concentration (CMC) value was determined to be 0.01 mg/mL. mPEG-CS-AZO nanomicelles can be formed spontaneously by the self-assembly in aqueous solution, which were used for the loading of avermectin (AVM), a representative photosensitive pesticide with poor water solubility. The mPEG-CS-AZO nanomicelles can act as UV protector for the loaded AVM, with a retention rate of 57.37 % following 60 h of UV exposure, attributing to that the irradiated UV light can be consumed through the efficient azobenzene trans-cis isomerization. The AVM release profiles fit the first-order model quite well. Therefore, the mPEG-CS-AZO nanomicelles can be applied as potential prospective carriers for photosensitive pesticides with the purpose of UV protective efficiency and sustained release.

Conductive Structural Colored Cotton Fabrics with Nonangle-Dependent Colors and Dynamic Thermal Management

Textile dyeing based on structural colors has attracted great attention due to its environmental friendliness and long-lasting color fastness. However, most studies on structural colored fabrics focus on only improving the color and stability of the fabric, neglecting the increasing demand for multifunctional textiles in daily life. Herein, a simple and effective method was used for preparing conductive structural colored cotton fabrics with nonangle-dependent colors and dynamic thermal management. To prepare structural color nanospheres with higher color rendering, PMMA nanospheres were coated with black PDA. The conductive structural colored fabric was obtained by self-assembling PMMA@PDA nanospheres onto MXene-modified cotton fabric through a simple blade coating method. The prepared conductive structural colored textile retains its softness and demonstrates good electrothermal performance and durable color fastness through washing, friction, and durability tests. This work provides a novel approach for creating bifunctional structural colored textiles that are suitable for electrothermal applications.

Enhanced anti-bacterial properties and thermal regulation via photothermal conversion with localized surface plasmon resonance effect in cotton fabrics

Enhanced anti-bacterial properties and thermal regulation are realized in cotton fabrics cross-linked with hybrid poly(di(ethylene glycol) methyl ether methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate-co-ethylene glycol methacrylate) nanogels containing gold nanoparticles (Au NPs), denoted as hybrid P(MA-co-MA300-co-EGMA)/Au nanogels. Pure P(MA-co-MA300-co-EGMA) nanogels are synthesized by emulsion polymerization as carriers and then embedded with Au NPs via in-situ reduction. By applying 1,2,3,4-butanetetracarboxylic acid as a cross-linker and changing the amount of hybrid P(MA-co-MA300-co-EGMA)/Au nanogels in solution, the weight gain ratios of hybrid nanogels on cotton fabrics are set as 10 % (CHN-10) and 20 % (CHN-20). Due to the densely packed structure of the hybrid nanogels on the surface, the localized surface plasmon resonance (LSPR) effect of the Au NPs improves the photothermal conversion capability and converts the absorbed light energy into thermal energy. Simply illuminating with visible light, the surface temperature of CHN-20 pronouncedly increases from 20.4 to 43.0 °C in 50 s. The increased local temperature induces the denaturation of protein and the death of bacteria on the surface. Thus, an illumination with visible light for 2 h results in an anti-bacterial rate for S. aureus of 100 % for CHN-20. Additionally, it presents an excellent thermal regulation capability via photothermal conversion and can be used for continuously maintaining human body temperature in cold areas. Because no additional chemical agents and external power source are required for the anti-bacterial properties and thermal regulation, the obtained cotton fabrics cross-linked with hybrid P(MA-co-MA300-co-EGMA)/Au nanogels are eco-friendly and suitable for smart textiles in daily wear.

Scalable Preparation of Superdurable, Self-Healing, and Biocompatible Superhydrophobic Poly(ethylene terephthalate) Fabrics

The chemical inertness of poly(ethylene terephthalate) (PET) fabrics poses challenges in achieving superhydrophobic coatings with durable adhesion on their surfaces. Conventional surface modification methods such as alkali etching and plasma etching typically compromise the favorable mechanical properties of PET. In this study, polydopamine (PDA) was utilized to functionalize the PET fabric nondestructively by creating robust and reactive hydroxyl and amine groups on its surface, which were subsequently used as a binder of superhydrophobic modifiers such as fluorine-free octadecyltrichlorosilane (OTS). By utilizing PDA to provide reactive groups, OTS undergoes self-assembly through hydrolysis on the surface of the PET fabric without introducing any inorganic nanoparticles while simultaneously forming low surface energy, strong covalent bonds, and rough surfaces. This robust material system provides a novel strategy to design and prepare superhydrophobic PET fabrics that can withstand extreme conditions and maintain superb water repellency even after 1000 times of abrasion and 100 washing cycles. Additionally, the room-temperature self-assembly properties of OTS provide the modified PET fabrics with efficient and repeatable room-temperature self-healing capability. This entire process through an environmentally friendly two-step immersion method enables large-scale production of superhydrophobic PET fabrics with wide applications in sports shoes and clothing.

Smart Green Cotton Textiles with Hierarchically Responsive Conductive Network for Personal Healthcare and Thermal Management

Whereas cotton as an abundant natural cellulose has been widely used for sustainable and skin-friendly textiles and clothes, developing cotton fabrics with smart functions that could respond to various stimuli is still eagerly desired while remaining a great challenge. Herein, smart multiresponsive cotton fabric with hierarchically copper nanowire interwoven MXene conductive networks that are seamlessly assembled along a 3D woven fabric template for efficient personal healthcare and thermal comfort regulation is successfully developed. The robust hierarchically interwoven conductive network was "glued" and protected by organic conductive polymer poly(3,4-ethylenedioxythiophene) along a 3D interconnected fabric template to enhance interfacial adherent and environmental stability. Benefiting from the robust multiresponsive hierarchically interwoven conductive network, smart cotton fabric exhibits real-time response to various external stimuli (light/electrical/heat/temperature/stress), and the details of human activities can be accurately recognized and monitored. Furthermore, the porous structure of 3D smart fabric induced strong capillary force and confinement to phase change materials PEG, which exhibits a wide range of phase transition temperatures for efficient thermal comfort regulation. After further encapsulation with transparent fluorosilicone resin, the smart cotton fabric exhibits excellent self-cleaning performance with water/oil repellent. The smart multiresponsive cotton fabrics hold great promise in next-generation wearable systems for efficient personal healthcare and thermal management.

Bioinspired Polydopamine Modification for Interface Compatibility of PDMS-Based Responsive Structurally Colored Textiles

Textiles that can repeatedly change color in the presence of external stimuli have attracted great interest. Effectively designing to produce such functional textiles is essential, yet there remain challenges like producing stable coloration, rapid response, and reverse color changing. Here, the preparation of a magnetic field response (MFR) textile with a fast magnetic field response, brilliant structural coloration, and mechanical robustness is reported. The MFR textile is knitted by incorporating magnetic particles' ethylene glycol (EG) suspension within polydimethylsiloxane (PDMS)-based fibers. A surface modification strategy is designed to prevent EG from seeping out along the PDMS polymer chains. A PDMS fiber is encapsulated in waterborne polyurethane, and a polydopamine joint layer is used. The MFR textile demonstrates magnetic field-triggered structural colors, and the breaking strength and elongation at break of each composite fiber are improved. In addition, multishaped patterns can be printed on the MFR textile with the help of the photo etching technology, which enhances the applications of the new functional textiles.

Toward a Sustainable Approach for Durably Hydrophilic and UV Protective PET Fabric through Surface Activation and Immobilization Integrating Epigallocatechin Gallate and Citric Acid

Enhancing the hydrophilicity and UV protective property of poly(ethylene terephthalate) (PET) fabric are two significant ways to upgrade its quality and enlarge the applicable area. Biobased finishes are greatly welcomed for the fabrication of sustainable textiles; however, their application on PET fabric is still challenging compared with the case of natural fabric. This study presents a strategy that immobilizes epigallocatechin gallate (EGCG) onto PET fabric using citric acid (CA) for durably hydrophilic and UV-proof properties with negligible color change. A controllable surface-activating method integrating alkaline and deep eutectic solvent (DES) is customized for the PET fabric to promote the reactions among PET, CA, and EGCG. The hydrophilic, antistatic, and UV protective properties of functionalized PET fabric were explored. Results show that the hydrophilicity of the PET fabric after direct EGCG treatment increases but drops sharply after first-round washing due to weak interactions. The combined alkaline/DES pretreatment increases the number of hydrophilic groups and the roughness of PET fibers. After EGCG modification, the moisture regain (MR) of PET fabric increases from 0.41 to 0.64%. The contact angle and electrostatic charge half-life (T1/2) decreases from >120 to 23°, and from >60 to 0.13 s, respectively. The MR and T1/2 are well retained after a 10-cycle washing. In addition, the UV protective factor of the PET fabric increases from 18 to 36. A very slight yellowing phenomenon occurs on the PET fabric after the treatment. In all, this research attempts to integrate a biobased finishing agent and an eco-friendly cross-linker on synthetic fiber for durable functions, which is transferrable to the sustainable fabrication of other polymeric materials such as fibers or films.

Preparation of polyphenol-structural colored silk fabrics with bright colors

Conventional textile dyeing relies on the use of dyes and pigments, which can cause severe environmental contamination and waste a large amount of water. Structural coloring is one of the effective ways to achieve environmentally friendly coloring of textiles. In this work, three plant polyphenols with the same o-benzenetriol structure (tannic acid (TA), gallic acid (GA), and tea polyphenol (TP)) were selected as raw materials. Three plant polyphenols can quickly form nanofilms at the gas-liquid interface through a Schiff base reaction with polyethyleneimine (PEI) under mildly alkaline conditions, which were deposited to the surface of silk fabric, allowing precise control over the thickness of film by adjusting the time, resulting in various structurally colored silk fabric. This method for creating structural colors is not substrate-specific and enables the quick production of structural colors on various textile substrates. Furthermore, the structural color silk fabric based on plant polyphenol has antibacterial performance. This textile coloring method is simple, cost-effective and environmentally friendly, providing a new approach to eco-friendly textile dyeing.

Enhanced UV protection in silk fibroin based electrospun fabrics realized via orientation induced high efficiency of azobenzene isomerization

Due to the poor UV protection capability, natural silk fabrics not only suffer from easy damage by sunshine but also induce possible sunburn in the human body. Efficient azobenzene isomerization and enhanced UV shielding are realized by replacing the natural silk with natural protein silk fibroin (SF) and electrospinning together with light-responsive copolymer P(MEO2-co-OEG300-co-AHMA). Compared to a solution cast film, the absorption peak intensity at 355 nm is 60 % higher in UV-Vis spectra of the electropsun SF/P(MEO2-co-OEG300-co-AHMA) fabrics. This improvement is related to the highly oriented chains, inducing more space and higher efficiency for azobenzene isomerization. Only exposure to visible light for 20 min, the absorption peak corresponding to the trans- state at 355 nm recovers to 92.5 % in the electrospun fabrics, which is at least 100 % faster than that in the solution cast film (50 min). It is related to the zip effect of the isomerization in the oriented chain structure. Thus, not only the absorption of UV radiation, but also the isomerization rate is enhanced. Based on these unique absorption and recovery capabilities, the SF based electrospun fabrics can be used to replace the natural silk fabrics for UV shielding in summer, especially for cyclic use.

Photothermoelectric Synergistic Hydrovoltaic Effect: A Flexible Photothermoelectric Yarn Panel for Multiple Renewable-Energy Harvesting

The human body is in a complex environment affected by body heat, light, and sweat, requiring the development of a wearable multifunctional textile for human utilization. Meanwhile, the traditional thermoelectric yarn is limited by expensive and scarce inorganic thermoelectric materials, which restricts the development of thermoelectric textiles. Therefore, in this paper, photothermoelectric yarns (PPDA-PPy-PEDOT/CuI) using organic poly(3,4-ethylenedioxythiophene) (PEDOT) and inorganic thermoelectric material cuprous iodide (CuI) are used for the thermoelectric layer and poly(pyrrole) (PPy) for the light-absorbing layer. With the introduction of PPy, the temperature difference of the photothermoelectric yarn can be increased for a better voltage output. Subsequently synergizing the photothermoelectric effect with the hydrovoltaic effect to create higher electric potentials, a single wet photothermoelectric yarn obtained by preparation can be irradiated under an infrared lamp at a voltage of up to 0.47 V. Finally, the photothermoelectric yarn PPDA-PPy-PEDOT/CuI was assembled in a series and parallel to obtain a photothermoelectric yarn panel, which was able to output 41.19 mV under an infrared lamp, and the synergistic photothermoelectric and hydrovoltaic effects of the photothermoelectric panel were tested outdoors on human body, and we found that the voltage was able to reach approximately 0.16 V under sunlight. Therefore, the voltage values obtained from the photothermoelectric yarns in this study are competitive and provide a new research idea for the study of photothermoelectric yarns.

Multiresponsive Self-Healing Lanthanide Fluorescent Hydrogel for Smart Textiles

Lanthanide organometallic complexes exhibit strong luminescence characteristics, owing to their antenna effects. The f-d energy level transition causes this phenomenon, which occurs when ligands and the external electrons of lanthanide metals coordinate. Based on this phenomenon, we used two lanthanide metals, europium (Eu) and terbium (Tb), in the present study as the metal center for iminodiacetic acid ligands. Further, we developed the resulting fluorescent organometallic complex as a smart material. The ligand-metal bond in the material functioned as a metal chelating agent and a cross-linking agent in a dynamically coordinated form, thereby prompting the material to self-heal. Temperature-sensitive poly-N-isopropylacrylamide was incorporated into the material as the polymer backbone. Afterward, we combined it with water-soluble poly(vinyl alcohol) and an additional ligand from poly(acrylic acid) to fabricate a high-performance hydrogel composite material. The shrinkage and expansion of the polymer form a grid between the materials. Because of the different coordination stabilities of Eu3+ and Tb3+, the corresponding material exhibits environmental responses toward excitation wavelength, temperature, and pH, thus generating different colors. When used in fabrics, the cross-linking mechanism of the material effectively looped the material between fabric fibers; furthermore, the temperature sensitivity of the polymer adjusted the size of pores between fabric fibers. At relatively higher temperatures (>32 °C), the polymer structure shrank, fiber pores expanded, and air permeability improved. Thus, this material appears to be promising for use in smart textiles.

Dual-Layer All-Textile Flexible Pressure Sensor Coupled by Silver Nanowires with Ti3C2-Mxene for Monitoring Athletic Motion during Sports and Transmitting Information

At present, wearable flexible pressure sensors have broad application prospects in fields such as motion monitoring and information transmission. However, it is still a challenge to design flexible pressure sensors with high sensitivity over a large sensing range and simple fabrication. Here, we use a simple "dipping-drying" method to fabricate a fabric-based flexible pressure sensor by coupling silver nanowires (AgNWs) with Ti3C2-MXene. The interaction between MXene and AgNWs helps realize a dual-layer sensing network, achieving good synergistic effects between pressure sensitivity and sensing range. The effects of the material combination and dip-coating sequence on the sensor's performance are systematically studied. The results show that the sensor was impregnated sequentially with AgNWs solution, and the MXene solution has the highest sensitivity (0.168 kPa-1) over a wide range (190 kPa). Meanwhile, it has the advantages of low response hysteresis and detection limit, as well as good linearity and durability. We further demonstrate the application of this sensor in human physiological signal monitoring and motion pattern recognition. It can also encrypt and transmit information according to different pressing states. In addition, the proposed pressure sensor array exhibits spatial resolution detection capabilities, laying the foundation for applications in the fields of motion monitoring and human-computer interaction.

Kinetics of UV Radiation-Induced Fast Collapse and Recovery in Thermally Cycled and Rehydrated Light- and Thermo- Double-Responsive Copolymer Films Probed by In Situ Neutron Reflectivity

The kinetics of UV radiation-induced fast collapse and recovery in thermally cycled and rehydrated light- and thermo- double-responsive copolymer films of poly(oligo(ethylene glycol) methyl ether methacrylate-co-6-(4-phenylazophenoxy)hexyl acrylate), abbreviated as P(OEGMA300-co-PAHA), are probed by in situ neutron reflectivity (NR). The copolymer film is exposed to a thermal treatment starting at a temperature of 60 °C, which is well above its transition temperature (TT = 53 °C) before the temperature is rapidly decreased from 60 to 23 °C. Based on the applied protocol, the initially collapsed P(OEGMA300-co-PAHA) film is rehydrated due to the switching of polymer chains from a more hydrophobic to a more hydrophilic state when the temperature falls below its TT. The whole rehydration process can be divided into 3 stages: D2O absorption, chain rearrangement, and film reswelling. After rehydration, the thermally cycled P(OEGMA300-co-PAHA) film is switched by UV irradiation via setting the UV radiation on and off. Considering the UV-induced collapse and recovery, both processes are slower than those observed in freshly hydrated films without any thermal stimulus history. Therefore, the experienced thermal history of the film should be considered in the design of sensors and detectors based on double-responsive copolymer films.

Construction of Wash-Resistant Photonic Crystal-Coated Fabrics based on Hydrogen Bonds and a Dynamically Cross-Linking Double-Network Structure

Structural coloration as the most possible way to realize the ecofriendly dying process for textiles or fabrics has attracted significant attention in the past decades. However, photonic crystals (PCs) are a typical example of materials with structural color usually located on the surface of the fabrics or textiles, which make them not stable when rubbed, bent, or washed due to the weak interaction between the PC coatings and fabrics. Here, double networks were constructed between the PC coatings and the fabrics for the first time via a hydrogen bond by introducing tannic acid (TA) and dynamic cross-linking with 2-formylphenylboronic acid to increase the wash resistance of the structural colored fabrics. On modifying the monodispersed SiO₂ nanoparticles, poly(dimethylsiloxane), and the fabrics, the interaction between the PC coatings and the fabrics increased by the formation of double networks. The structural color, wash, and rub resistance of the PC-coated fabrics were systematically studied. The obtained fabrics with the TA content at 0.030% (SiDT30) showed the best wash and rub resistance. The construction of double networks not only improved the wash and rub resistance of PCs but also retained the bright structural color of the PC coatings, facilitating the practical application of structural coloration in the textile industry.

Nonwoven Membranes with Infrared Light-Controlled Permeability

This study presents the development of the first composite nonwoven fiber mats (NWFs) with infrared light-controlled permeability. The membranes were prepared by coating polypropylene NWFs with a photothermal layer of poly(N-isopropylacrylamide) (PNIPAm)-based microgels impregnated with graphene oxide nanoparticles (GONPs). This design enables "photothermal smart-gating" using light dosage as remote control of the membrane's permeability to electrolytes. Upon exposure to infrared light, the GONPs trigger a rapid local increase in temperature, which contracts the PNIPAm-based microgels lodged in the pore space of the NWFs. The contraction of the microgels can be reverted by cooling from the surrounding aqueous environment. The efficient conversion of infrared light into localized heat by GONPs coupled with the phase transition of the microgels above the lower critical solution temperature (LCST) of PNIPAm provide effective control over the effective porosity, and thus the permeability, of the membrane. The material design parameters, namely the monomer composition of the microgels and the GONP-to-microgel ratio, enable tuning the permeability shift in response to IR light; control NWFs coated with GONP-free microgels displayed thermal responsiveness only, whereas native NWFs showed no smart-gating behavior at all. This technology shows potential toward processing temperature-sensitive bioactive ingredients or remote-controlled bioreactors.

Facile Preparation of Silk Fabrics with Enhanced UV Radiation Shielding and Wrinkle Resistance by Cross-Linking Light-Responsive Copolymers

Enhanced UV radiation shielding is realized by cross-linking the light-responsive copolymer poly(di(ethylene glycol)methyl ether methacrylate-co-oligo(ethylene glycol)methyl ether methacrylate-co-ethylene glycol methacrylate-co-6-(4-phenylazo-phenoxy)hexyl methacrylate), abbreviated as PMOEA, with silk fabrics. Owing to the existence of the azobenzene component in 6-(4-phenylazo-phenoxy)hexyl methacrylate, UV radiation can be significantly absorbed in an aqueous PMOEA solution by the trans-cis isomerization of azobenzene. After immobilization onto the silk fabrics by the cross-linker 1,2,3,4-butanetetracarboxylic acid, the cross-linked copolymer-coated silk fabrics present an enhanced capability of UV radiation absorption. More than 70% of the UV radiation is efficiently shielded by the cross-linked copolymer-coated silk fabrics, which is double that of the original silk fabrics. Considering the limited amount of the light-responsive copolymer applied (5 wt %), UV protection is successfully realized for the silk fabrics. In addition, the cross-linked copolymer layer also forms covalent bonds with the hydroxyl and amino groups on the silk fabrics. Wrinkles on the silk fabrics, typically caused by the movement of the silk chains, are suppressed by the formed covalent bonds, significantly hindering such chain movement. Therefore, the wrinkle resistance capability is also improved by cross-linking PMOEA on silk fabrics. As the glass transition temperature of the copolymer is lower than room temperature, the hand feel of silk fabrics is not affected by the cross-linking layer. Based on these advantages, the cross-linked copolymer-coated silk fabrics can be used for light clothes to shield against UV radiation from the sun during outdoor activities in summer.

Robust multifunctional fluorine-free superhydrophobic fabrics for high-efficiency oil-water separation with ultrahigh flux

The limited robustness and complex preparation process greatly hinder the large-scale use of superhydrophobic surfaces in real life. In this work, we adopt a simple method to prepare robust fluorine-free superhydrophobic cotton fabrics by a facile dip-coating method based on silica microparticles and titanium dioxide nanoparticles. Microparticles and nanoparticles are used to build a suitable rough hierarchical structure, while strong bonds are formed between fabric and particles by a silane coupling agent. The cross-linking reaction between the isocyanate group of trimers of hexamethylene diisocyanate (HDI) and the hydroxyl group of each component in the condensation reaction further increases the bonding between the coating and the cotton fabric. In addition, polydimethylsiloxane (PDMS) is used as a low-surface-energy material to modify the fabric surface. The resulting coating shows excellent superhydrophobic properties with a water contact angle of 161.7°. Meanwhile, the prepared superhydrophobic fabric exhibits excellent durability and stability after sandpaper wearing, washing, and UV radiation, as well as treatment with various organic solutions, boiling water and different pH solutions. Moreover, the superhydrophobic fabric displays excellent UV protection performance and high oil-water separation efficiency (>99% after 30 cycles) with ultrahigh flux up to 20 850 L m^-2 h^-1.

Preparation of Structural Color on Cotton Fabric with High Color Fastness through Multiple Hydrogen Bonds between Polyphenol Hydroxyl and Lactam

Structural coloration is an important way to realize eco-friendly dyeing of textiles. Structural colored cotton fabric was obtained by fabricating a polydopamine (PDA) film on the white cotton fabric at different polymerization reaction times. PDA is prone to generate capillary tension during film formation, which damages the uniformity and interfacial bonding force of the film. Multiple hydrogen bonds will form between the lactam group of polyvinylpyrrolidone (PVP) and the phenolic hydroxyl group of PDA. The introduced hydrogen bonds will effectively enhance the interfacial bond strength and lead to structural color with high color fastness. The surface morphology of double-layer aggregates of the PDA film on structural colored cotton fabric was revealed by scanning electron microscopy. The chemical constitution of the PDA film and PVP was investigated by Fourier transform infrared spectroscopy and X-ray diffraction. The color characteristics of structural colored cotton fabrics were analyzed by UV-vis reflectance spectroscopy and spectrophotometry.

Dual-stimuli-responsive porous polymer enzyme reactor for tuning enzymolysis efficiency

A strategy for preparing a dual-stimuli-responsive porous polymer membrane enzyme reactor (D-PPMER) is described, consisting of poly (styrene-maleic anhydride-N-isopropylacrylamide-acrylate-3',3'-dimethyl-6-nitro-spiro[2H-1-benzopyran-2,2'-indoline]-1'-esterspiropyran ester) [P(S-M-N-SP)] and D-amino acid oxidase. Tunable control via "on/off" 365 nm UV light irradiation and temperature variation was used to change the membrane surface configuration and adjust the enzymolysis efficiency of the D-PPMER. A chiral capillary electrophoresis technique was developed for evaluation of the enzymatic efficiency of D-PPMER with a Zn(II)-dipeptide complex as the chiral selector and D,L-serine as the substrate. Interestingly, the enzymatic kinetic reaction rate of D-PPMER under UV irradiation at 36 °C (9.2 × 10^-2 mM·min^-1) was 3.2-fold greater than that of the free enzyme (2.9 × 10^-2 mM·min^-1). This was because upon UV irradiation at high temperature, the P(SP) and P(N) moieties altered from a "stretched" to a "curled" state to encapsulate the enzyme in smaller cavities. The confinement effect of the cavities further improved the enzymatic efficiency of the D-PPMER. This protocol highlights the outstanding potential of smart polymers, enables tunable control over the kinetic rates of stimuli-responsive enzyme reactors, and establishes a platform for adjusting enzymolysis efficiency using two different stimuli.