Antibacterial cotton fabrics via immobilizing silver phosphate nanoparticles onto the chitosan nanofiber coating

Construction of durable antibacterial cellulose textiles through grafting dynamic disulfide-containing amino-compound and nanosilver deposition

Cotton textile is very comfortable to wear, and also provides an ideal environment for bacterial propagation, easily causing harm to human health. In order to address this issue, various antibacterial techniques are employed for cotton finishing. However, some processes are complex and involve the use of environmentally unfriendly chemicals. In this work, a durable and efficient antibacterial cotton fabric was prepared via grafting of an amino-compound containing dynamic disulfide bonds, and then in-situ deposition of silver nanoparticles (AgNPs). Briefly, the reactive α-lipoic acid-modified polyethyleneimine (mPEI) was introduced to the cotton fibers via thiol-ene click reaction. Subsequently, the amino groups and dynamically-generated sulfhydryl groups in the mPEI molecules were used to initiate the ultrafast reduction of silver ions without the participation of additional reductant, constructing a stable antibacterial layer on fiber surface. The results reveal that the amino and thiol groups of mPEI could form coordination bonds with the deposited silver nanoparticles, and the antibacterial ability of AgNP@cotton-g-mPEI fabric remains at a high level even after 20 washing cycles. After 30 min of contact with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), the antibacterial rates against both bacteria reached 99.99 %. Meanwhile, the network matrix constructed by the recombination of the dynamic disulfide bonds in mPEI endows the cotton fabric with detectable wrinkle resistance and encouraging anti-ultraviolet effect. The present work provides a novel alternative for preparation of durable and efficient antibacterial textiles.

Preparation of conductive cellulose fabrics with durable antibacterial properties and their application in wearable electrodes

Electroless silver plating on fabrics can obtain conductive and antibacterial bifunctional materials which can be used as electrodes in wearable electronic products. However, these activities are deteriorated easily after washing because of the falling off of silver coating resulted from the weak adhesion. In order to improve the binding force between silver and cellulose fabrics, 3-mercaptopropytrimethoxysilane (MPTS) was applied to modify cellulose fabrics before silver electroless plating to develop the durable conductive fabrics with excellent antibacterial. The silver nanoparticles (Ag NPs) deposition process was observed via field emission scanning electron microscopy (FESEM), thermal properties were evaluated by thermogravimetric analysis (TGA). A dense and uniform silver layer was formed on the fabric. The initial electrical resistance of the conductive fabric was 0.04 Ω/sq and lowered than 2 Ω/sq after 200 washing cycles. The antibacterial efficiency of the fabric after 200 washing cycles remained 92.82%, compared to 100% with the fabric before washing. Moreover, the inhibition rate was determined by optical density of bacteria suspension at 260 nm and further substantiated by releasing of Ag⁺ from the fabric. The conductive fabrics were applied as wearable electrodes to capture electrocardiogram (ECG) signals of human in static states and running states.