Chitosan-coated electrospun waste polystyrene microfiber as mask filter

Abstract

Waste expanded polystyrene is one of the significant contributors to global waste. Its disposal has been a problem due to its low density causing too much space take up in landfills. The utilization of waste-expanded polystyrene as a mask filter through electrospinning process is done in this study. It is annealed and coated with chitosan to improve mechanical strength and bacterial filtration efficiency. The annealed fiber mat has an average fiber diameter of 2.80±1.24 μm while the annealed and coated fiber averaged 3.52±1.87 μm. The bacterial filtration efficiency test shows 99.84±0.22% efficiency for the coated filter and 64.58±8.84% efficiency for the non- coated filter. The results imply that incorporating chitosan significantly improved the filtration efficiency of the filter. Moreover, the addition of chitosan increased the ultimate tensile strength from 0.72±0.08 MPa to 9.86±1.24 MPa and turned the hydrophobic EPS microfiber (89.83±1.48° contact angle) to a hydrophilic microfiber (51.61±4.47° contact angle). On the other hand, there is no significant difference in the differential pressure between the coated (5.40±0.17 mm H2O per cm2) and non-coated (5.58±1.54 mm H2O per cm2) mask filter. Adding chitosan does not increase the pressure drop across the filter. Lastly, the produced chitosan-coated waste-expanded polystyrene mask filter qualifies for ASTM Level 3 for medical and surgical masks in terms of bacterial filtration efficiency and differential pressure. Thus, the electrospun EPS microfiber mask filter can potentially be applied to standard surgical masks while presenting a simple and environmentally friendly waste EPS upcycling.