Scalable Poly(organosiloxane)-Modified Air Filtration Media for Reducing Indoor Airborne Transmission of SARS-CoV-2 and Other Contagions

Abstract

Mounting empirical evidence supporting the notion of airborne transmission of communicable infectious diseases, such as COVID-19, continues to shift the consensus toward increasing indoor air quality safety standards in common spaces. Airborne viral transmission is particularly problematic in rationally designing next-generation heating, ventilation, and air-conditioning (HVAC) system technologies to cost-effectively remove airborne biological contaminants from shared indoor environments. Holistic strategies for managing indoor air quality in shared commercial spaces often rely on HVAC disinfection technologies (e.g., ultraviolet light-C irradiation and bipolar ionization) or the use of functionalized air filters such as resistively heated Ni-foam filters and Ag nanocluster/silica nanocomposite coatings, both of which are costly to implement and maintain. Many existing HVAC systems are unable to accommodate simple operational changes (e.g., static pressure, incident air temperature, and outdoor-to-recirculated air ratios) while maintaining acceptable set points and energy efficiency. This work is the first report on a scalable SARS-CoV-2-capturing waterborne poly(organosiloxane)-based coating, named microbial and viral transmission resistance (MVTR), that is applied directly to HVAC air filtration media as a retrofit without adversely affecting breathability or static pressure upon curing/cross-linking. Real-time quantitative polymerase chain reaction studies demonstrate that MVTR-treated MERV-8 air filters are more effective at filtering a challenge aerosol of thermally inactivated SARS-CoV-2 virions than untreated MERV-13 air filters. MVTR reduces concentrations of airborne SARS-CoV-2 using lower MERV-rated air filters while preserving energy efficiency without imposing operational restrictions on HVAC systems and is another preventive countermeasure against indoor contagion, synergistically augmenting best hygiene practices, social distancing, disinfectants, virucidal nanomaterials, novel vaccines, and existing antiviral pharmaceuticals.