Structure‐Performance Relationship of Electrospun PAN‐Based Nanofibrous Membranes for Air Filtration: Role of Surface Skewness and Packing Density

ABSTRACT

Electrospun nanofibrous membranes are promising candidates for air decontamination because of their high surface‐to‐volume ratio, tunable pore structure, and low basis weight. However, the rapid screening of membrane performance before full filtration testing remains challenging. In this study, polyacrylonitrile (PAN)‐based nanofibrous membranes were fabricated by electrospinning using pristine PAN and PAN modified with halloysite nanotubes (HNTs), polyamidoamine (PAMAM) dendrimers, and their hybrid combination. The effects of these additives on fiber morphology, viscosity, surface topography, packing density, mechanical response, thermal behavior, and particulate filtration performance were systematically evaluated. The incorporation of nanoparticles significantly impacted the membrane structure, resulting in a 20%–55% reduction in nanofiber diameter, which directly altered the packing density and surface properties. An empirical structural descriptor, termed the structural quality factor (QF _S ), was evaluated by combining packing density with the absolute value of surface skewness. The descriptor showed a preliminary correlation with the experimental filtration quality factor, suggesting its potential use for preliminary screening of electrospun filter media.