RAPID: Polyelectrolyte Coatings as an Approach to Extend N95 Respirator Usage Lifespan

Engineering - This project will address the critical shortage of N95 respirator masks currently facing medical professionals at the front lines of the evolving novel coronavirus 2019 (COVID-19) pandemic. The research will leverage the expertise of the investigators to develop a simple and effective approach for extending the usable life of N95 respirator masks and similar personal protective equipment (PPE). The investigators will explore the application of commercially available polyelectrolytes (a polymer with a repeating charged unit) as thin film coatings on the masks. These coatings can potentially deactivate enveloped viruses such as SARS-COV-2, increase the barrier to penetration by viral particles, and maintain performance integrity after solvent-based sterilization protocols. An independent laboratory will evaluate the performance of the modified masks relative to the National Institute for Occupational Safety and Health (NIOSH) N95 standards. Clinical professionals at Mt. Sinai School of Medicine in New York City, a region currently battling the highest infection rate, will test prototype masks and work with the investigators to perfect the coating procedure. The outcome of the project will be a coating protocol that uses non-toxic components and can be applied by end users in a hospital setting on procured masks. Findings will be made immediately accessible to the public through pre-print servers, public repositories such as the Open Science Framework, and social media platforms. Accordingly, society can work together to mitigate the impact of the PPE shortage and minimize further infections through clinician-patient contacts.

The overall goal of the project is to develop a simple and effective post-processing step to coat manufactured nonwoven polypropylene materials, e.g., N95 mask filters, in polyelectrolyte solutions. This is expected to impart a thin, uniform conformal coating exhibiting a semi-permanent charge. The polyelectrolyte coating will extend the usable life of existing medical PPE supplies by enabling use of common sterilization procedures. The polyelectrolyte coating may also augment the protective capabilities of PPE by enhancing material filtering efficiency and/or providing novel antiviral activity. The investigators will evaluate and optimize a coating procedure that healthcare personnel can directly apply to acquired PPE using commodity polymers. Incorporation of alkyl halides in the coating and polymer cross-linking will be explored to yield highly functional and resilient coatings. Scanning electron microscopy will be used to characterize coating uniformity, changes to material fiber structure, and resulting pore size distribution. Breathability after polymer coating will be assessed by measuring air permeation through the mask, and viral deactivation capabilities will be investigated through cytopathic and plaque formation assays with a model Biosafety Level II enveloped virus. An independent commercial laboratory will conduct NIOSH pre-certification testing to assess particle filtration relative to N-series respirator standards. Partners at the Mt. Sinai Icahn School of Medicine will test and implement prototypical processes in real time to resolve the PPE shortage.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.