Pore-structure, hydrophilicity, and particle filtration characteristics of polyaniline-polysulfone ultrafiltration membranes

A highly processable form of polyaniline was synthesized and used to form pure polyaniline and polyaniline-polysulfone ultrafiltration membranes by nonsolvent induced phase inversion. Blends containing up to 75% polyaniline were 10-20% more permeable than pure polysulfone membranes, while pure polyaniline membranes were 10 times more permeable and extremely hydrophilic. A novel scanning electron microscope imaging technique was combined with characterization data and the Hagen-Poiseuille pore-flow model to elucidate that increasing polyaniline content increased the apparent membrane pore size and hydrophilicity, while decreasing skin layer thickness and porosity. Pure polyaniline membranes exhibited relatively larger, shorter pores that combined with the increased hydrophilicity to produce the observed separation performance enhancements.