A continuous polytetrafluoroethylene foam-coating to glass fiber mat with superior self-cleaning, antistatic and high filtration efficiency performances

Abstract

Air pollution has become a significant global environmental issue, leading to adverse health effects and respiratory diseases. To address this challenge, expanded polytetrafluoroethylene (ePTFE) membrane-based fibrous filters have gained popularity in the past decade. However, the thinness and low mechanical strength of ePTFE membranes make them susceptible to damage from particle collisions. As an alternative to ePTFE membranes, PTFE emulsion has emerged as a promising approach to enhance filtration efficiency. However, due to PTFE's low surface energy and high crystallinity, it is difficult for PTFE to self-bond into a membranes and adhere to substrates. Therefore, the filtration efficiency of PTFE-impregnated filter materials does not meet the requirements for ultra-low emissions, and they have poor wear resistance, resulting in a short service life. Herein, we fabricate a PTFE emulsion foam-coating membrane filter. The influences of the contents of PVA on the film morphology, air permeability, pore size and distribution, abrasive resistance and antistatic properties were analyzed. The self-cleaning performance was simulated and the filtration performance was measured as well. Notably, the frictional mass loss index of the PTFE emulsion foam-coating membrane filter was 0.07. After 30 cycles, the filtration efficiency was 98.93%, and the strip ratio was 91.03%. Our design of the PTFE emulsion foam-coating provided a new direction for the application of PTFE emulsion in the filtration field with superior self-cleaning, antistatic and high filtration efficiency performances.