화학공학소재연구정보센터
Desalination, Vol.445, 85-94, 2018
Preparation of polyvinylidene fluoride blend anion exchange membranes via non-solvent induced phase inversion for desalination and fluoride removal
Non-solvent induced phase inversion is a scalable, cost-effective, and fast process for the preparation of pressure driven membranes. Despite of the advantages, this process is hitherto unreported in the preparation of ion exchange membranes. Herein, we report the preparation of supported anion exchange membranes of polyvinylidene fluoride (PVDF) blend poly(methyl methacrylate)-co-poly(chloromethyl styrene) (PMMA-co-PCMSt) by the non-solvent induced phase separation process followed by post treatment with tertiary diamine. The obtained membranes were partially crosslinked due to the nucleophilic substitution reaction of diamine with the activated halide groups of the blend membrane. A series of membranes was obtained by changing the PVDF to copolymer ratio. These membranes were used for the desalination as well as removal of fluoride ions via the electrodialysis (ED) process. A membrane prepared with blend containing 69.5%, w/w copolymer and 30.5% w/w PVDF exhibited best electrochemical properties with ion-exchange capacity 1.85 meq g(-1), ionic conductivity 3.02 mS cm(-1), and transport number 0.98. This AEM also showed 0.978 kWh kg(-1) power consumption and 94% current efficiency during desalination of water at 2 V/cell pair applied potential. The AEMs obtained by this process showed good hydrolytic and oxidative stability. This process thus highlights simple and fast preparation of high performance AEMs for water desalination and purification.