(152bp) Chemically Immobilized Silver Nanoparticles on Polysulfone Membrane Filter for High Efficacy Antimicrobial Protection in Face Mask and Air Filtration Applications.

The COVID-19 pandemic has brought to light the vital importance of high performing air filters in various systems, including heating, ventilation, and air conditioning (HVAC), personal protective equipment (PPE), microelectronics, and automobiles. The market for air filters is expected to experience an annual growth rate of 7.1%, reaching $22.15 billion by 2028, with HEPA filters being particularly significant for face mask production and HVAC systems. While commercially available filters provide high protection against aerosolized microbes, their performance may be reduced when exposed to common regeneration techniques due to the dissipation of charges on their surface responsible for their high filtration efficiency. To address this limitation, flat sheet membranes have been studied as a potential solution, achieving high particulate filtration efficiency (>99.5% for 0.3µm particles) that does not reduce on exposure to common regeneration treatments due to their mechanical filtration mechanism. However, these polymeric membranes can trap aerosolized microbes on their surface for an extended period, which can lead to cross contamination and the further spread of diseases if not handled properly. To address this issue, we present a study aimed at developing an antimicrobial membrane for face mask and air filtration applications by chemically immobilizing silver nanoparticles (an antimicrobial agent) onto a polysulfone membrane filter. We utilized a low-cost, polymerized epoxy, glycidyl methacrylate-cysteamine complex to attach thiol groups to the fabricated membrane surface, enabling the immobilization of silver nanoparticles. FTIR analysis confirmed successful polymerization of the mono glycidyl methacrylate, while electron dispersive spectroscopy and x-ray photoelectron spectroscopy verified the presence of silver on the polysulfone membrane surface. Leaching studies conducted on the functionalized membrane showed an insignificant release of silver nanoparticles, well below the contamination levels suggested by the EPA (100 ppb). Our results demonstrate the potential of this innovative approach to reduce cross contamination and improve the efficacy of face masks and air filters in protecting against the spread of infectious diseases.