Construction of sustainable and multifunctional polyester fabrics via an efficiently and eco-friendly spray-drying layer-by-layer strategy

Spray-assisted layer-by-layer deposition of quaternized chitosan/tannic acid for the construction of multifunctional bio-based nonwoven dressings

Gauze wound dressings have received considerable attention due to their cost-effectiveness, excellent mechanical properties, and widespread applications. However, their inability to actively combat microorganisms and effectively scavenge free radicals results in suboptimal wound management. In this study, a novel nonwoven-based gauze dressing coated with quaternized chitosan/tannic acid (QCS/TA), based on electrostatic interaction and hydrogen bonding, was successfully prepared using a spray-assisted layer-by-layer assembly method. The bio-based nonwoven dressing, assembled with multiple interlacing bilayers, demonstrated outstanding antimicrobial properties, eliminating 99.99 % of Staphylococcus aureus (S. aureus) and 85 % of Escherichia coli (E. coli). Compared to the pristine nonwoven dressing, the QCS/TA-coated nonwoven dressing scavenged >85 % of the surrounding radicals within 2 h. Additionally, the nonwoven dressing exhibits excellent coagulation properties. Notably, the facile spraying procedure preserved most of the softness and breathability of the nonwoven substrate. After the deposition of seven bilayers, the bending stiffness and drape coefficient increased by only 37.63 % and 3.85 %, respectively, while the air permeability and moisture permeability reached 1712 mm/s and 3683.58 g/m2/d, respectively. This bio-based nonwoven dressing, derived from safe and non-toxic ingredients, holds promise as the next generation of multifunctional gauze dressings.

Non-ionic surfactant PEG: Enhanced cutinase-catalyzed hydrolysis of polyethylene terephthalate

To enhance the enzymatic digestibility of polyethylene terephthalate (PET), which is highly oriented and crystallized, a polyethylene glycol (PEG) surfactant of varying molecular weights was utilized to improve the stability of mutant cutinase from Humicola insolens (HiC) and to increase the accessibility of the enzyme to the substrate. Leveraging the optimal conditions for HiC hydrolysis of PET, the introduction of 1 % w/v PEG significantly increased the yield of PET hydrolysis products. PEG600 was particularly effective, increasing the yield by 64.58 % compared to using HiC alone. Moreover, the mechanisms by which PEG600 and PEG6000 enhance enzyme digestion were extensively examined using circular dichroism and fluorescence spectroscopy. The results from CD and fluorescence analyses indicated that PEG alters the protein conformation, thereby affecting the catalytic effect of the enzyme. Moreover, PEG improved the affinity between HiC and PET by lowering the surface tension of the solution, substantially enhancing PET hydrolysis. This study suggests that PEG holds considerable promise as an enzyme protector, significantly aiding in the hydrophilic modification and degradation of PET in an environmentally friendly and sustainable manner.

Polyester fabrics coated with cupric hydroxide and cellulose for the treatment of kitchen oily wastewater

In recent years, kitchen oily wastewater has received much attention because of its harmful effects on the ecological environment. Therefore, separation of oil from kitchen oily wastewater has become an urgent issue. In this study, this problem could be solved using polyester fabrics covered with cupric hydroxide and cellulose. The functional fabric was obtained by the dipping-rolling-drying process which is an easy and practical way to prepare the fabric and could improve the hydrophilicity of polyester. The functional polyester fabric could separate oil/water mixtures completely under the force of gravity with a high water flux of 2079 L m^-2 h^-1-3620 L m^-2 h^-1 and high separation efficiency of 99.6%. Because kitchen oily wastewater contains floating oil and emulsified oil, we also tested the separation of oil-in-water emulsions. The functional polyester fabric could successfully separate the emulsions with the water flux of 1210 L m^-2 h^-1-2018 L m^-2 h^-1 and a separation efficiency of 99.0%. Moreover, the water flux and separation efficiency of functional polyester fabric remained unchanged after the immersion in salt, alkali, and acid solutions, indicating that the functional polyester fabric exhibited commendable environmental stability. The oil in Chongqing Street Noodles soup with a high oil content was separated to simulate real-life oil/water separation, confirming that the functional polyester fabric could be applied to the treatment of kitchen oily wastewater.

Mussel-Inspired Design of a Self-Adhesive Agent for Durable Moisture Management and Bacterial Inhibition on PET Fabric

Functional textiles with advanced moisture management can enhance human comfort and physiological health. However, conventional wet finishing processes used for textiles are usually highly polluting and exhibit poor fastness. Inspired by the strong underwater adhesion properties of mussels based on cation-π interaction, a novel superhydrophilic polymeric molecule with strong cohesion and adhesion property is designed on a poly(ethylene terephthalate) (PET) fabric. The cation-π hydrophilic agent (CPHA) can efficiently transform the hydrophobic PET fabric to a superhydrophilic one, and its superhydrophilicity can withstand 150 home laundry cycles. In addition, the cationic moieties in the CPHA self-adhere to the PET fabric without any finishing auxiliary that would cause pollution. Due to its strong adhesion, CPHA can be applied to one side of the PET fabric via spray coating and curing to form a Janus hydrophobic/superhydrophilic fabric capable of diode-like one-way sweat transportation (with forward transportation capability of 1115% and backward transportation capability of -1509%). Moreover, the Janus fabric inhibits bacterial growth and invasion, while simultaneously preserving the inner ecological healthy balance of the skin's microflora. This work opens up a pathway to develop adhesives in textile wet processing for more diverse, smarter applications, e.g., quick-dry sportswear, protective suits, or air-conditioning fabrics.

Roll-to-roll layer-by-layer assembly bark-shaped carbon nanotube/Ti3C2Tx MXene textiles for wearable electronics

Smart wearable electronics have drawn increasing attention for their potential applications in personal thermal management, human health monitoring, portable energy conversion/storage, electronic skin and so on. However, it is still a critical challenge to fabricate the multifunctional textiles with tunable morphology and performance while performing well in flexibility, air permeability, wearing comfortability. Herein, we develop a novel roll-to-roll layer-by-layer assembly strategy to construct bark-shaped carbon nanotube (CNT)/Ti₃C₂T_x MXene composite film on the fiber surface. The fabricated bark-shaped CNT/MXene decorated fabrics (CMFs) exhibit good flexibility, air permeability and electrical conductivity (sheet resistance, 6.6 Ω/□). In addition, the CMFs demonstrate good electrothermal performance (70.9 °C, 5 V), electromagnetic interference (EMI) shielding performance (EMI shielding effectiveness, 30.0 dB under X-Brand), and high sensitivity as the flexible piezoresistive sensors for monitoring the human motions. Importantly, our CMFs show distinctive EMI shielding mechanism, where a great proportion of incident electromagnetic microwaves are reflected by the bark-shaped CNT/MXene films owing to the multi-interface scattering effects. This work may provide a new strategy for the fabrication of multifunctional textile-based electronics and pave the way for smart wearable electronics.