Study of Polysulfone and Polyacrylic Acid (PSF/PAA) Membranes Morphology by Kinetic Method and Scanning Electronic Microscopy

Abstract

This work focuses on the study of the morphology forming of Polysulfone (PSf) and polyacrylic acid (PAA) membranes which are prepared by mixing both of the polymers in DMF and the obtained blend is precipitated in water (non-solvent). The precipitation kinetic and the effects of polysulfone concentration, drying-time in free-air and proportions of both polymers are investigated. Based on the SEM technique, the kinetic and viscosity measurements, and the visual observations, this study brings to the fore the different steps of the morphology forming of PSf/PAA membranes: formation of finger-like structures, sponge-like-structures, inner pores, superficial pores and the craters. Appearance of these structures is governed by the exchange process, between casting polymer-solution and the precipitation-bath (coagulation), which is controlled by operating conditions. This work constitutes a great tool in understanding the mechanisms of the morphology forming of PSf/PAA membranes and to improve their performances: preparation of tailored membrane.