Protection against airborne viruses has become very relevant since the outbreak of SARS-CoV-2. Nonwoven face masks along with heating, ventilation, and air conditioning (HVAC) filters have been used extensively to reduce infection rates; however, some of these filter materials provide inadequate protection due to insufficient initial filtration efficiency (FE) and FE decrease with time. Flat sheet porous membranes, which have been used extensively to filter waterborne microbes and particulate matter due to their high FE have the potential to filter air pollutants without compromising its FE over time. Therefore, in this study, single layer polysulfone (PSf) membranes were fabricated via non-solvent induced phase separation (NIPS) and were tested for airflow rate, pressure drop and FE. Polyethylene glycol (PEG) and glycerol were employed as pore-forming agents, and the effect of the primary polymer and pore-forming additive molecular weights (MW) on airflow rate and pressure drop were studied at different concentrations. The thermodynamic stability of dope solutions with different MWs of PSf and PEG in N-methylpyrrolidone (NMP) at different concentrations was determined using cloud-point measurements to construct a ternary phase diagram. Surface composition of the fabricated membranes was characterized using contact angle and X-ray photoelectron spectroscopy (XPS), while membrane morphology was characterized by SEM, and tensile strength experiments were performed to analyze the membrane mechanical strength (MS). It was observed that an increase in PSf and PEG molecular weight and concentration increased airflow and decreased pressure drop. PSf60:PEG20:NMP (15:15:70)% w/w showed the highest air flow rate and lowest pressure drop, but at the expense of the mechanical strength, which was improved significantly by attaching the membrane to a 3D-printed polypropylene support. Lastly, the FE values of the membranes were similar to those of double-layer N95 filters and significantly higher than those of single layer of N95, surgical mask and HVAC (MERV 11) filters.
|State||Published - Jul 2022|
Bibliographical noteFunding Information:
This research was funded by the National Science Foundation (NSF) under Cooperative Agreement (grant number 1849213), by the NSF KY EPSCoR Program. All imaging was possible thanks to Kentucky IDeA Networks of Biomedical Research Excellence (KY-INBRE) grant P20GM103436.
images for pristine (a) PSf35 membrane (P1) and (b)PSf35:PEG20 15:15 w/w (P7); Figure S4. Schematic S.5. Schematic showing dogbone for mechanical strength test; S.6. Surface pore size distribution of showing membrane-mesh support attachment; Figure S5. Schematic showing dogbone for mechanical PSf35 (P1); S.7. Surface pore size distribution of PSf60 (P2); S.8. Surface pore size distribution of strength test; Figure S6. Surface pore size distribution of PSf35 (P1); Figure S7. Surface pore size PSf35:PEG20 (P7); S.9. Surface pore size distribution of PSf60:PEG20 (P9); S.10. Surface pore size distribution of PSf60 (P2); Figure S8. Surface pore size distribution of PSf35:PEG20 (P7); Figure S9. Surface pore size distribution of PSf60:PEG20 (P9); Figure S10. Surface pore size distribution of Author Contributions: Data collection-E.A.O., L.S. and A.H.; writing–original draft preparation E.A.O.; writing-review and editing I.C.E.; funding acquisition E.W. and I.C.E. All authors have read test through membranes fabricated using NaCl as an additive. and agreed to the published version of the manuscript. Author Contributions: Data collection—E.A.O., L.S. and A.H.; writing–original draft preparation Funding: This research was funded by the National Science Foundation (NSF) under Cooperative E.A.O.; writing-review and editing I.C.E.; funding acquisition E.W. and I.C.E. All authors have read Agreement (grant number 1849213), by the NSF KY EPSCoR Program. All imaging was possible andthanagrks eedto toKenthetupublishedcky IDeAversionNetworofks theof manuscript.Biomedical Research Excellence (KY-INBRE) grant
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- 3D printing
- air filtration
- filtration efficiency
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Process Chemistry and Technology
- Filtration and Separation