(578g) Antimicrobial Membrane Filters for Face Mask Production

The Covid 19 pandemic has led to growing demands for personal protective equipment (PPE) to effectively control the spread of the virus. Facemasks are an effective defense against aerosols containing pathogenic bacteria and viruses such as Sars-Cov-2. Membrane filters have been used extensively in face masks to remove these microbes from the air. These filters are usually designed for single-use due to inadequate and laborious cleaning/decontamination techniques. Common treatments like the use of detergents and chemicals effectively deactivate microbial activities; however, the integrity of the filter material could be compromised, leading to a reduction in filtration efficiency. Ultraviolet light and microwave are good candidates for treatment, but storage after use and transportation of infected masks to treatment sites can lead to cross-contamination. This work attempts to make a breathable antiviral face mask by immobilizing silver nanoparticles (AgNPs), which could suppress bacterial and viral activity on a cellulose acetate (CA) membrane filter required for mask production. Attaching the AgNP’s directly to CA when making the membrane is not effective because AgNP’s leaches very fast from CA at room temperature. AgNp was chemically immobilized by attaching a polymerized epoxy, glycidyl methacrylate (GMA) to CA, allowing for more functionalization of the CA/GMA copolymer. Cysteamine was then combined with the CA/GMA complex, providing thiol groups that immobilized AgNP’s on the membrane surface. FTIR analysis confirmed the successful polymerization of the monoGMA, while electron microscopy and X-ray energy dispersive spectroscopy was used to verify the presence of silver on the CA membrane surface. An airflow test was carried out on the unmodified CA membrane to ensure breathability. A high airflow resistance was observed through the membrane at pressures up to 10psi. This was hypothesized to be due to small pore sizes inherent in biobased membranes. Therefore, polyethylene glycol (PEG), an organic chemical known to form pores in membranes, was introduced in the dope solutions, and subsequent increases in pore sizes and air permeability were observed.