Antimicrobial textiles effective against SARS-CoV-2 functionalized by silver nanoparticles in PVA

Background, Motivation and Objective The COVID-19 pandemic has increased the demand for producing efficient materials against microbes and viruses, including protective clothing and facemasks. Additionally, the costs related to nosocomial infections push industries to develop antibacterial materials with high efficiency and low cost. In particular, microbial resistance to antibiotics is an important problem that draws attention towards antibacterial nano-products. On the other hand, the release of nanoparticles from goods and during manufacturing is a matter of concern from an environmental and human health point of view. In the present work, in response to the battle against SARS-CoV-2, an eco-friendly process is used to produce highly concentrated suspensions of silver nanoparticles (AgNPs) applied on textiles with antiviral and antibacterial properties suitable for the engineering of facemasks and protective textiles. Statement of Contribution/Methods Silver nanoparticles were synthesized in water at room temperature from AgNO3 by means of hydroxyethyl cellulose (HEC) according to the patented procedure (Patent WO 2016125070). AgHEC/PVA solutions were produced using poly(vinyl alcohol) (PVA) dissolved in hot water at 1 wt/vol %. When the PVA solution was cooled down, AgHEC NPs water dispersion at a concentration of 0.1 wt% was added at a volume ratio 1:1 under stirring. AgHEC/PVA solutions were sprayed on three different types of fabrics: a) polypropylene spunbonded non-woven (PPNW); b) polyamide fabric (PA 6,6); c) polyethylene terephthalate fabric (PET). Results/Discussion For testing the antiviral activity of AgHEC-coated fabrics, the virus SARS-CoV-2 inoculum was put on the specimen (ISO 18184 protocol). The Ag-containing fabrics showed an antiviral activity of ~33 % compared with the untreated substrates (without Ag). The Ag-containing fabrics showed a strong antibacterial activity with a bacterial reduction of 100% against Escherichia coli (Gram negative). Antibacterial tests were also performed after abrasion and washing. AgHEC/PVA solutions were applied to fabrics by spray producing a stable coating with antiviral and antibacterial properties. Antibacterial tests were performed after abrasion and washing. These results, comparable to our previous ones obtained on nanofibers coated filter media [M. Blosi, A.L. Costa, S. Ortelli, F. Belosi, F. Ravegnani, A. Varesano, C. Tonetti, C. Vineis, J. Applied Polymer Sci,138, e51380, 2021], further confirmed the strong adhesion of AgHEC NPs to fabrics, leading to efficient antimicrobial activity.