Modeling of asymmetric membrane formation by a combination of dry/wet phase inversion processes

Abstract

The invention of asymmetric polymer membranes by Loeb and Sourirajan has caused an enormous growth in the field of membrane science and technology. Application areas range from chemical, biomedical to biotechnology industries. Asymmetric membranes are mostly fabricated by a process called phase inversion which can be achieved through four principal methods: immersion precipitation (wet phase inversion), vapor-induced phase separation, thermally induced phase separation and dry-casting. In these techniques, an initially homogeneous polymer solution becomes thermodynamically unstable and phase separates into polymerlean and polymer-rich phases. Structure of these types of membranes is greatly influenced by even slight change in membrane preparation conditions.