Controlling the Morphology of Polyvinylidene-co-hexafluoropropylene (PVDF-co-HFP) Membranes Via Phase Inversion Method

• Published in: Membrane Journal Vol. 28; no. 3; pp. 187 - 195
• Main Authors: Song, Ye Jin, Kim, Jong Hoo, Kim, Ye Som, Kim, Sang Deuk, Cho, Young Hoon, Park, Ho Sik, Nam, Seung Eun, Park, You In, Son, Eun Ho, Kim, Jeong F.
• Format: Journal Article
• Language: English
• Published: 한국막학회 30.06.2018
• Subjects: 화학공학
• ISSN: 1226-0088; 2288-7253
• DOI: 10.14579/MEMBRANE_JOURNAL.2018.28.3.187

In this work, the morphology of polyvinylidene-co-hexafluoropropylene (PVDF-co-HFP) membranes were systemically investigated using phase inversion technique, to target membrane contactor applications. As the presence of macrovoids degrade the mechanical integrity of the membranes and jeopardize the long-term stability of membrane contactor processes (e.g. wetting), a wide range of dope compositions and casting conditions was studied to eliminate the undesired macrovoids. The type of solvent had significant effect on the membrane morphology, and the observed morphology were correlated to the physical properties of the solvent and solvent-polymer interactions. In addition, to fabricate macrovoid-free structure, the effects of different coagulation temperatures, inclusion of additives, and addition of nonsolvents were investigated. Due to the slow crystallization rate of P(VDF-co-HFP) polymer, it was found that obtaining porous membrane without macrovoids is difficult using only nonsolvent-induced phase separation method (NIPS). However, combined other phase inversion methods such as evaporation-induced phase separation (EIPS) and vapor-induced phase separation (VIPS), the desired membrane morphology can be obtained without any macrovoids. KCI Citation Count: 1