Study on the gelation kinetics in polyethersulfone with cardo asymmetric ultrafiltration membrane

Polyethersulfone with cardo (PES-C) was a developed engineering thermoplastic and membrane material with high glass transition temperature, PES-C ultrafiltration membranes were prepared by phase inversion method using dimethylacetamide (DMAC) as solvent and oxalic acid (OA) and polyethylene glycol as additives. The membrane morphology forming and evolution could be observed by the experimental system and method. The effect of additive and polymer concentration on cast solution and the gelation kinetics of polyethersulfone with cardo asymmetric membrane were studied. The result showed that the gelation kinetics and membrane morphology were coincident. It was found that the relation between the square of gelation front motion and time was nonlinear, the gelation kinetics process did not follow the Fick diffusion behavior, which was different from the result of Strathman et al.