A superhydrophobic and heat-resistant PAN/PSU/PTFE composite nanofiber membrane for high-efficiency PM1.0 and PM2.5 filtration

Abstract

Excessive particulate matter (PM) concentrations in the air can negatively impact the environment and harm human health. Hence, this issue must be addressed immediately. In this study, we developed a filtration membrane for PM_1.0 and PM_2.5 based on polyacrylonitrile/polysulfone/polytetrafluoroethylene (PAN/PSU/PTFE) composite nanofibers using an electrospinning method. Numerous characterization studies (i.e., scanning electron microscopy (SEM), water contact angle (WCA) measurement, Fourier-transform infrared (FTIR) spectroscopy, tensile strength test, and thermogravimetric analysis (TGA)) were conducted to determine the surface morphology, hydrophobicity level, chemical composition, mechanical strength, and heat resistance of nanofibers, respectively. The fabricated PAN/PSU/PTFE nanofibers possess smooth and continuous morphology with sizes ranging from 270 to 407 nm, superhydrophobic surface characteristics (WCA > 153°), and temperature stability at 300 °C. Furthermore, in terms of their performance as a PM filter, they demonstrate high filtration efficiency values of (99.2 ± 0.2)% and (99.3 ± 0.2)% for PM_1.0 and PM_2.5 with a pressure drop of (415 ± 5) Pa, resulting in quality factor (QF) values of (11.7 ± 0.6) × 10⁻³ Pa⁻¹ and (11.9 ± 0.7) × 10⁻³ Pa⁻¹, respectively. In addition, the membrane still maintains its performance after 4 months. All these results indicate the high potential of the proposed PAN/PSU/PTFE nanofiber membrane as a PM filter in harsh environments.