Air filtration performance enhancement of PTFE foam–coated filters at high temperatures via secondary strongly adhering PTFE nanofiber coatings

A PTFE nanofiber–coated PG filter (that is, a modified PTFE foam–coated glass fabric filter (PG filter)) is developed with superior particulate matter (PM) collection efficiency under high-temperature conditions. A modified electrospinning solution is used to coat the PTFE foam surface of the PG filter with nanofibers (precursors to PTFE nanofibers); this electrospinning solution contains poly(ethylene oxide) whose amphipathicity promotes adhesion between the nanofibers and PTFE foam. Consequently, a PTFE NF–coated PG filter shows enhanced adhesion between the PTFE nanofibers and PTFE-foam surface of PG filter. The PM collection efficiency of and pressure drop across the proposed PTFE nanofiber–coated PG filter were investigated at various temperatures; the air filtration performance of filter exceeds that of a conventional PG filter. In particular, the PM1.0 collection efficiency of the PTFE nanofiber–coated PG filter is 1.13 times higher than that of a PG filter at 280 °C.