Image enhancement of polyethersulfone ultrafiltration membrane surface structure for atomic force microscopy

Abstract

Abstract The surface topography and pore structure of ultrafiltration membranes can be investigated with atomic force microscopy. In this study, it was found that the substitution of ethanol for water as the immersion medium improved the resolution of the fine structure of 10K polyethersulfone ultrafiltration membranes. Pores in the membrane surface from 7 to 9 nm in diameter were measured, which coincides with the range expected for 10,000 molecular weight cutoff (MWCO) ultrafiltration membranes. It is believed that this image enhancement results from increased damping and concomitant noise reduction resulting from the higher viscosity of ethanol in contrast to water.