Facile fabrication of multifunctional cotton fabric by AgNC@boronate polymer/crosslinked chitosan

Regulating molecular brush structure on cotton textiles for efficient antibacterial properties

The molecular brush structures have been developed on cotton textiles for long-term and efficient broad-spectrum antimicrobial performances through the cooperation of alkyl-chain and quaternary ammonium sites. Results show that efficient antibacterial performances can be achieved by the regulation of the alkyl chain length and quaternary ammonium sites. The antibacterial efficiency of the optimized molecular brush structure of [3-(N,N-Dimethylamino)propyl]trimethoxysilane with cetyl modification on cotton textiles (CT-DM-16) can reach more than 99 % against both E. coli and S. aureus. Alkyl-chain grafting displayed significantly improvement in the antibacterial activity against S. aureus with (N,N-Diethyl-3-aminopropyl)trimethoxysilane modification on cotton textiles (CT-DE) based materials. The positive N sites and alkyl chains played important roles in the antibacterial process. Proteomic analysis reveals that the contributions of cytoskeleton and membrane-enclosed lumen in differentially expressed proteins have been increased for the S. aureus antibacterial process, confirming the promoted puncture capacity with alkyl-chain grafting. Theoretical calculations indicate that the positive charge of N sites can be enhanced through alkyl-chain grafting, and the possible distortion of the brush structure in application can further increase the positive charge of N sites. Uncovering the regulation mechanism is considered to be important guidance to develop novel and practical antibacterial materials.

Aldehyde-free and bio-based durable coatings for cellulose fabrics with high flame retardancy, antibacteria and well wearing performance

The bio-based coatings of cellulose fabrics (cotton) had attracted increasing attention for multifunction and sustainability but suffered from poor durability and low efficiency. Here, the aldehyde-free and durable coatings for cotton fabrics (CPZ@CF) with satisfactory flame retardancy, antibacteria as well as wearing performance were prepared through the interfacial coordination effect where the well-organized zinc phytate complex were in situ grew on the pre-treated surface of cotton fabrics with chitosan (CS) and Zn2+. The CZP@CF exhibited excellent antibacterial activity for Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with 99.99 % antibacterial rates benefiting from the synergistic effect between Zn2+ and CS. Meanwhile, even the CPZ coatings loading was only 1.5 wt%, the fire safety of CZP@CF remarkably enhanced owing to the excellent synergistic catalytic charring and free radical capture. More importantly, the antibacterial rates of CZP@CF for S. aureus and E. coli still reached 99.99 % and 91.67 % after 50 washing cycles. Additionally, this treatment method did not deteriorate the fabrics properties, including mechanical and breathability as well as wearing performance, which provided the approach to fabricate the flame retardant and antibacterial textiles with well durability and wearing performance.

Bimetallic silver-platinum (AgPt) nanoparticles and chitosan fabricated cotton gauze for enhanced antimicrobial and wound healing applications

Wound healing is a significant clinical and socioeconomic problem that is often affected by microbial infection. Inappropriate monitoring leads to unfavorable concerns for surrounding tissues. Cotton gauzes have been used as low-cost wound dressing material but prolong healing owing to strong adherence and secondary microbial infections. Hence, we prepared the bimetallic (silver and platinum) nanoparticles (AgPt NPs) using citric acid (CA) as a reducing agent and then coated them on chitosan (CS) fabricated cotton gauze (CG) for enhanced antimicrobial and wound healing applications. The synthesis of AgPt NPs was evidenced UV-Visible spectroscopy, FE-TEM, and elemental mapping analysis. The average size of AgPt NPs was 21.48 ± 6.32 nm and spherical in structure. Besides, AgPt NPs showed a hydrodynamic size of 63.64 (d.nm) with a polydispersity index of 0.220 and a zeta potential of -28.1 mV. The FT-IR and XRD analysis demonstrated the functional changes and crystalline properties of AgPt NPs. The antimicrobial efficacy of AgPt NPs was significantly higher than standard antibiotic against bacteria, yeast, and filamentous fungi. Furthermore, the AgPt NPs-CS/CG exhibited a substantial hydrophobic nature with better antimicrobial and antioxidant activity. In addition, pH-dependent Ag and Pt release from the AgPt NPs-CS/CG was determined by ICP-MS analysis. The treatment of AgPt NPs-CS/CG augmented the in vitro wound healing in mouse embryonic fibroblast cells (NIH3T3). Hence, we concluded that AgPt NPs-CS/CG could be used to enhance antimicrobial and wound healing applications.

Tailorable antibacterial and cytotoxic chitosan derivatives by introducing quaternary ammonium salt and sulfobetaine

Chitosan (CS) derivatives with improved water solubility, antibacterial activity and adequate biocompatibility are attracting increasingly interest in medical application. Herein, we have successfully synthesized isocyanate terminated quaternary ammonium salt (IQAS) and sulfopropylbetaine (ISB) to be readily covalently bounded to CS skeleton by selective reaction with amino and hydroxyl groups. And their molecular structures and crystallinity were confirmed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and X-ray diffraction. The effect of the substitution degree, carbon chain length, content ratio of IQAS/ISB on their water solubility, antibacterial activity and cytotoxicity were systematically investigated, which shows that those properties of the CS derivatives can be tailored by adjusting the grafted antibacterial agents and their additive amount. The structure-property relationship of these CS derivatives may provide a solid guidance on the development of CS derivatives for more efficient practical applications.

Durable antibacterial cotton fabric fabricated using a "self-created" mist polymerization device

There are two major problems associated with the use of antibacterial cotton fabric. The durability of the fabric is poor, and the inherent properties of the fabric deteriorate following the execution of the finishing processes. These limit the application of antibacterial fabric. We first treated the cotton fabric with acryloyl chloride (AC) molecules to make the surface of the fabric rich in carbon‑carbon double (C=C) bonds. Following this, the [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (DMES) monomer was polymerized with the CC bonds on the fabric following the "grafting through" method. As a result, the cotton fabric was successfully grafted with the poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PDMES), exploiting covalent bonds. The finished fabric exhibited excellent antibacterial effects. The bacterial reduction (BR) rates of the finished fabric against E. coli and S. aureus were greater than 99.0 %. Even after 50 washing cycles, the BR rates of the finished fabric against E. coli and S. aureus were greater than 96.0 %. In addition, the use of the "self-created" mist polymerization technology ensured that the inherent properties of the finished fabric were retained to a large extent. Therefore, the antibacterial cotton fabric prepared following this method can be potentially used for the fabrication of industrial and household textiles.