Antibacterial Superhydrophobic Cotton Fabric with Photothermal, Self-Cleaning, and Ultraviolet Protection Functionalities

Green Nanoengineered Fabrics: Waste-Derived Polyphenol-Zinc@ Silica Core-Shell Reactive Janus Nanoparticles for Functional Fabrics

Fabricating Janus nanoparticle-functionalized fabrics with UV protection, strength enhancement, self-cleaning properties, and wash durability, with a biocompatible nature, is crucial in modern functional fabrics engineering. Particularly, tailoring multifunctional nanoparticles capable of exhibiting several distinct properties, utilizing low-cost raw materials, and adhering to green chemistry principles is pivotal. A fabrication strategy for developing multifunctional reactive Janus nanoparticles, utilizing waste-derived natural polyphenol (quercetin-3-glucuronide, myricetin-3-galactoside, gossypin, phlorizin, kaempferol, myricetin-3-arabinoside)-integrated zinc-silica core-shell Janus nanoparticles with UV protection, strength enhancement, and self-cleaning properties, is proposed. Polyphenols were utilized as sustainable precursors for synthesizing zinc-polyphenol complexes, which were then encapsulated within a silica shell to form a core-shell structure. Furthermore, Janus particles were created by introducing a bifunctional layer with half amine/carboxylic acid and half methyl terminals, imparting reactive hydrophilic and hydrophobic properties. Janus-coated textiles and leather exhibited significant attenuation of harmful UV radiation, with water contact angle measurements confirming improved water repellency. The coexistence of natural phenols and bifunctional groups within a material bolstered textile strength, fostering superior adhesion and markedly enhancing wash durability. This eco-friendly approach, utilizing waste-derived materials, presents a promising solution for sustainable textile engineering with enhanced performance in UV protection and water resistance, thereby contributing to the advancement of green nanotechnology in textile applications.

Apt-Conjugated PDMS-ZnO/Ag-Based Multifunctional Integrated Superhydrophobic Biosensor with High SERS Activity and Photocatalytic Sterilization Performance

Sensitive detection and efficient inactivation of pathogenic bacteria are crucial for halting the spread and reproduction of foodborne pathogenic bacteria. Herein, a novel Apt-modified PDMS-ZnO/Ag multifunctional biosensor has been developed for high-sensitivity surface-enhanced Raman scattering (SERS) detection along with photocatalytic sterilization towards Salmonella typhimurium (S. typhimurium). The distribution of the electric field in PDMS-ZnO/Ag with different Ag sputtering times was analyzed using a finite-difference time-domain (FDTD) algorithm. Due to the combined effect of electromagnetic enhancement and chemical enhancement, PDMS-ZnO/Ag exhibited outstanding SERS sensitivity. The limit of detection (LOD) for 4-MBA on the optimal SERS substrate (PZA-40) could be as little as 10-9 M. After PZA-40 was modified with the aptamer, the LOD of the PZA-40-Apt biosensor for detecting S. typhimurium was only 10 cfu/mL. Additionally, the PZA-40-Apt biosensor could effectively inactivate S. typhimurium under visible light irradiation within 10 min, with a bacterial lethality rate (Lb) of up to 97%. In particular, the PZA-40-Apt biosensor could identify S. typhimurium in food samples in addition to having minimal cytotoxicity and powerful biocompatibility. This work provides a multifunctional nanoplatform with broad prospects for selective SERS detection and photocatalytic sterilization of pathogenic bacteria.

Bio-based phytic acid/amino acid complex coating for antimicrobial and flame-retardant cotton fabrics

Here, a novel multifunctional coating containing bio-based phytic acid (PA), L-glutamic acid (L-Glu), and trimesoyl chloride (TMC) is constructed by a simple soaking strategy, giving cotton fabrics excellent flame retardancy, washability, and antibacterial properties. The coating layer on the cotton surface was prepared via the electrostatic and hydrogen bonding between PA and L-Glu, accompanied by the interface polymerization between PA, L-Glu, and TMC. Among them, the limiting oxygen index value of the treated cotton fabrics (C2 and C2-TMC) was as high as 40 %. During the vertical flammability test, both C2 and C2-TMC cotton showed self-extinguished behavior with a short damaged length (≤50 mm). Remarkably, the LOI of C2-TMC sustained a high value (30 %) even after 300 laundering cycles, maintaining its self-extinguishing behavior in the vertical combustion test. Additionally, in the cone calorimetry test, peak heat release rate and total heat release of treated cotton were lower than control cotton. Surprisingly, after 30 or 60 laundering cycles, the C2-TMC cotton exhibited excellent antibacterial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans due to the continuous exposure of PA and L-Glu. Moreover, the coating layer on the cotton surface had little impact on the mechanical properties and feel of the fabric.

Effect of the Photoreduction Process on the Self-Cleaning and Antibacterial Activity of Au-Doped TiO2 Colloids on Cotton Fabric

This study aims at understanding the effect of the photoreduction process during the synthesis of gold (Au)-doped TiO2 colloids on the conferred functionalities on cotton fabrics. TiO2/Au and TiO2/Au/SiO2 colloids were synthesized through the sol-gel method with and without undergoing the photoreduction step based on different molar ratios of Au:Ti (0.001 and 0.01) and TiO2/SiO2 (1:1 and 1:2.3). The colloids were applied to cotton fabrics, and the obtained photocatalytic self-cleaning, wet photocatalytic activity, UV protection, and antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria were investigated. The obtained results demonstrated that the photoreduction of Au weakened the self-cleaning effect and reduced the photocatalytic activity of coated fabrics. Also, an excess amount of Au deteriorated the photocatalytic activity under both UV and visible light. The most efficient self-cleaning effect was obtained on fabrics coated with a ternary TiO2/Au/SiO2 colloid containing ionic Au, where it decomposed coffee and red-wine stains after 3 h of illumination. Adding silica (SiO2) made the fabrics superhydrophilic and led to greater methylene blue (MB) dye adsorption, a faster dye degradation pace, and more efficient stain removal. Moreover, the photoreduction process affected the size of Au nanoparticles (NPs), weakened the antibacterial activity of fabrics against both types of tested bacteria, and modestly increased the UV protection. In general, the photoactivity of Au-doped colloids was influenced by the synthesis method, the ionic and metallic states of the Au dopant, the concentration of the Au dopant, and the presence and concentration of silica.

Photothermal, superhydrophobic, conductive, and anti-UV cotton fabric loaded with polydimethylsiloxane-encapsulated copper sulfide nanoflowers

Multifunctional textiles have attracted widespread attention with the improvement of awareness of health. Especially, the fluorine-free superhydrophobic and conductive cellulose fiber-based fabrics have received intensive interest due to their broad and high-value applications. Herein, the copper sulfide nanoflowers were in-situ deposited on cotton fabric followed by polydimethylsiloxane (PDMS) treatment for encapsulating CuS nanoflowers and obtaining superhydrophobicity, recorded as Cot@PTA@CuS@PDMS. Cot@PTA@CuS@PDMS possesses superhydrophobicity with contact angles of 153.0 ± 0.4°, photothermal effect, excellent UV resistance, good conductivity, and anti-fouling. Interestingly, the resistance of Cot@PTA@CuS@PDMS is significantly reduced from 856.4 to 393.1 Ω under simulated sunlight irradiation with 250 mW/cm2. Notably, the resistance can be slightly recovered after shutting off simulated sunlight. Besides, Cot@PTA@CuS@PDMS has efficient oil-water separation efficiency for corn germ oil and castor oil, respectively. Briefly, this work provides a novel, facile, and promising strategy to fabricate multifunctional fiber-based textiles with the reversible change of resistance under simulated sunlight irradiation, inspiring more scholars to control the resistance change of textiles by light irradiation.

Smart Janus cotton fabrics prepared via mist polymerization for moisture and thermal management

The construction of Janus structures on cotton fabrics can endow the fabrics with dynamic multifunctional properties. However, because of the large pores between fabric fibers, the formation of Janus structures by grafting different functional coatings on the double surfaces of cotton fabrics via dipping technology is difficult. To construct Janus structures on cotton fabrics, mist polymerization and "grafting-through" polymerization technologies were used to graft polylauryl methacrylate and a heat-shrinkable thermosensitive antibacterial polymer on the inside and outside surfaces of the cotton fabric, respectively. The as-formed Janus cotton fabric demonstrated excellent antibacterial durability. Even after subjecting the Janus fabric to 70 laundering cycles, its bacterial rates against Escherichia coli and Staphylococcus aureus were > 93.0 %. Compared with the pristine cotton fabric, when the ambient temperature is high or low, the Janus fabric can adjust the skin temperature within 5 min by approximately ±3.0 °C. Additionally, the fabric exhibited excellent waterproof and moisture permeability properties. The Janus cotton fabrics prepared by the proposed strategy possess significant potential for applications in the field of wearable textiles.

A durable hydrophobic photothermal membrane based on a honeycomb structure MXene for stable and efficient solar desalination

Solar powered water evaporation is a green and environmentally friendly water treatment technology, which is a hot research topic for water purification at present. Advanced structural design and hydrophilic photothermal materials have achieved efficient solar evaporation of pure water, but the long-term stability of high salinity desalination has become a problem that cannot be ignored in practical applications. In order to solve this problem, a hydrophobic honeycomb structure MXene/AuNFs composite membrane was proposed in this paper, which used the three-dimensional highly porous microstructure of MXene and multibranched structure of gold nanoflowers particles to improve the light absorption and photothermal conversion efficiency of MXene/AuNFs. At the same time, the surface of the composite membrane was modified with hydrophobic fluorosilane 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFTE). The hydrophobic layer can prevent the accumulation of salt particles on the surface of the membrane, so that the composite film can continue to produce water vapor in a high salt environment. With high utilization rate of light energy, multiple-level geometrical structures of MXene for rapid water transport on the filter membrane and salt barrier on the membrane good stability, the hydrophobic MXene/AuNFs achieves solar evaporation rate of 1.59 kg m-2 h-1 and solar conversion efficiency is 97.8%, and stable operation under simulated sea water conditions under one sun irradiation over more than 10 cycles. The hydrophobic MXene/AuNFs membrane proved to be an efficient and stable photothermal material for solar desalination.

Rational design and easy fabrication of transparent photothermal/hygroscopic composite coatings with long-lasting antifogging performance under sunlight activation

Hygroscopic polymers are good candidates for antifogging coatings, but their long-term effectiveness is limited by the equilibrium between water absorption and expansion. As an efficient and environmentally friendly solution, photothermal materials are being introduced into the field of antifogging. However, there is a need for enhancement in the spectral characteristics of most photothermal materials within the visible light region. In addition, photothermal antifogging coatings often exhibit a delay in heating response, which hinders their ability to promptly evaporate condensed water droplets in the absence of illumination or during initial illumination. Here, a bilayer structure design of photothermal nanomaterials/hygroscopic polymers is proposed to achieve long-term antifogging under sunlight activation. Ensuring the rapid absorption of condensed water droplets on the coating surface, while simultaneously achieving efficient photothermal conversion for a swift temperature increase over the entire coating, is key to this approach, which will not only suppress early fogging but also lead to an exponential decrease of the nucleation rate of droplets. During this process, a dynamic equilibrium is gradually established between the condensation and evaporation of fog droplets, leading to long-term antifogging properties. The light transmittance of the composite coatings reaches as high as ca. 75% in the visible light region, making them well suited for a diverse range of transparent substrate and device applications. A clear field of view can be maintained for at least 6 h under 1 sun illumination above 65 °C hot steam. The antifogging/defogging performance is effectively demonstrated even under challenging non-ideal natural conditions, such as low solar irradiation during dusk or when placed indoors behind windows.

Preparation of multifunctional cellulose macromolecule blended fabrics through internal and external synergy by N1, N6-bis (ethylene oxide-2-ylmethyl) hexane-1,6-diamine

With the diversification of people's demand for textile functions, the preparation of multifunctional fabrics is still a current research hotspot. In this study, the water-soluble epoxy compound N1, N6-bis(oxiran-2-ylmethyl) hexane-1,6-diamine (EH) was introduced into cellulose macromolecule blended fabrics (cotton/modal) by two-phase vaporization technique, resulting in excellent wrinkle, hydrophobicity, and certain UV protection effects. It could be observed by electron microscopy that EH formed a polymer film on the fiber surface. In addition, the results of EDS scans and fiber swelling rate tests showed that EH was uniformly distributed and formed a cross-linked structure in the amorphous zones inside the fibers. Compared with the control fabrics, the wrinkle recovery angle of the EH-treated fabric was increased by 39.7 %. The fabrics could reach a contact angle of 136.9°, providing excellent hydrophobic effect. In addition, the fabrics achieved certain UV protection effects (UPF of 50+). The EH-treated fabrics were less stabilized in strong acid and alkali conditions, but exhibited greater durability in other environments. In summary, the internal and external synergistic effects of EH in forming polymer films on the fibers surface and internal cross-linking structures provided a cleaner, simple, and feasible method for the preparation of multifunctional cellulose macromolecule fibers textiles.

Highly Antibacterial and Self-Healing Janus Fabric for Effective Body Moisture/Thermal Management and Durable Waterproof

Despite the development of many functional fabrics, they are unable to meet practical needs due to their monolithic functions and low durability. Therefore, a multifunctional waterborne polyurethane nanodroplet containing disulfide bonds (WSPU) was synthesized using a simple and environmentally friendly approach. The functional WSPU nanodroplet coating endowed fabrics with a variety of properties, including exceptional hydrophobicity, antibacterial properties, self-healing at room temperature, directional transport, etc. The functionalized fabric demonstrated durable mechanical and chemical stabilities due to the combined effects of disulfide bond reconstruction and hydrophobic chain migration. It exhibited the ability to regain its hydrophobic properties at room temperature after 50 friction cycles were performed without requiring external stimulation. Furthermore, the fabric maintained a water contact angle above 140°, even after being subjected to washing, boiling, and immersion in acid and alkali solutions. In addition, as a result of the fabric's Janus-like wettability, it performed various functions in accordance with varying weather conditions, in terms of wearing comfort and breathability. In hot weather or during exercise, the Janus fabric with the hydrophilic side facing outward enhances the process of sweat-directed perspiration, resulting in a notable cooling effect. On rainy days, the Janus fabric, when positioned with the hydrophobic side facing outward, exhibited excellent waterproof performance. This study presents an opportunity to explore the development of multifunctional fabrics through the combined effects of several functions.

Photothermal Superhydrophobic Cotton Fabric Based on Silver Nanoparticles Cross-Linked by Polydopamine and Polyethylenimide

Photothermal materials that can convert solar energy into heat energy through photothermal conversion have attracted extensive attention, but these materials are easily polluted by the environment. Here, we propose a simple and effective strategy for constructing photothermal superhydrophobic cotton fabrics with self-cleaning ability. The PDA@PEI@GA@Ag@PDMS-coated cotton fabric can achieve good superhydrophobicity (water contact angle: 159.6°) by a simple dipping method and mussel-inspired dopamine surface modification, which is regulated by the mass of dopamine, the mass of silver nitrate, and the concentration of polydimethylsiloxane (PDMS). The coated cotton fabric has good physical and chemical stability. Meanwhile, the coated cotton fabric has excellent self-cleaning and antifouling properties. The superhydrophobic PDA@PEI@GA@Ag@PDMS fabric exhibits excellent and stable photothermal properties, with the surface temperature reaching 70.4 °C under simulated sunlight with a current of 20 A. This photothermal superhydrophobic fabric with self-cleaning properties is expected to be applied in the field of photothermal conversion.