We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Investigation of Biodegradable and Non-Biodegradable Solvents for the Fabrication of Polylactic Acid Membranes via Nonsolvent Induced Phase Separation (NIPS) for Air Filtration Applications
Summary
Researchers fabricated polylactic acid (PLA) air filtration membranes using biodegradable solvents (ethyl acetate and gamma-butyrolactone) as replacements for toxic, persistent solvents, finding that ethyl acetate-based membranes achieved superior thermal stability and hydrophobicity while maintaining filtration efficiency above 95% for 0.3-micrometer aerosols.
The substitution of hazardous, environmentally persistent solvents (NMP and DMAc) with more sustainable alternatives (ETAc and GBL) in fabricating flat sheet polyactic acid (PLA) membranes via nonsolvent-induced phase separation for air filtration applications was the focus of this study. The polymer-solvent affinity was first evaluated using Hansen solubility parameters, confirming suitable Relative Energy Difference (RED) values (<1) for all solvent candidates. Dope solutions prepared with biodegradable solvents demonstrated higher viscosity compared to those prepared with environmentally persistent solvents. These biodegradable solvent systems also exhibited slower precipitation rates during membrane formation. This resulted in spongelike cross-sectional morphologies, contrasting with the combined fingerlike and spongelike structures observed in membranes fabricated with environmentally persistent NMP and DMAc. Thermal analysis revealed that membranes fabricated with biodegradable solvents exhibited superior thermal stability with higher glass transition temperatures (Tg = 54.39–55.34 °C) compared to those made with environmentally persistent solvents (Tg = 49.97–50.71 °C). Membranes fabricated with ethyl acetate (ETAc) showed the highest hydrophobicity (contact angle = 115.1 ± 9°), airflow rate (12.7 ± 0.28 LPM at 0.4 bar) and maintained filtration efficiency at values greater than 95% for 0.3 μm aerosols.