Effect of citrate-based non-toxic solvents on poly(vinylidene fluoride) membrane preparation via thermally induced phase separation

The replacement of commonly-used substances with non-toxic equivalents is attracting a great amount of attention in membrane preparation processes. In order to address this issue, we prepared poly(vinylidene fluoride) (PVDF) flat membranes via thermally-induced phase separation using non-toxic citrate-based solvents (Citroflex): acetyl tributyl citrate (ATBC); acetyl triethyl citrate (ATEC); and triethyl citrate (TEC). It was found that the three kinds of Citroflex showed the different solubility with PVDF: the solubility was improved in the following order of ATBC