Design and Construction of Double-Layered Nanofiber/Microfiber Composite Nonwovens for High-Temperature Filtration Application

The airborne particulate matter (PM) poses a severe risk to human health worldwide, and developing high-temperature resistant material with high filtration performance is crucial for the effective removal of industrially generated PM. In this study, a novel double-layered composite nonwoven (CN) constructed with one layer of polyphenylene sulfide (PPS) needle-punching felt (NF) and one layer of polysulfone-amide (PSA) nanofiber mat (NM) was designed and implemented for potential high-temperature filtration application. In details, an electrospinning strategy was first employed to fabricate PSA NMs with adjustable fiber diameters. Then, a thermal-pressing post-treatment was utilized to realize the combination of PSA NM and commercial PPS NF, to generate a PSA/PPS CN. The electrospun PSA nanofibers were found to be uniformly covered on the PPS microfibers after the thermal-press process, resulting in a stable micro-/nano-fibrous structure. It was found that the PSA/PPS CN with the 120 μm thickness of nanofiber mat possessed 100% filtration efficiency to both of the DEHS PM and NaCl PM with the particle sizes ranging from 0.225 to 7.25 μm. In addition, the CN also presented high thermal stability. In all, this study provides a simple and easily-handling strategy for fabricating a high-temperature resistant nano-/micro-fibrous CN with high filtration performance, which shows huge potential for high-temperature air filtration application.