For water filtration applications, we find PVDF (semi-crystalline polymer, m.p ~ 177 C) as one of most suitable candidates for water filtration. In our experience with it in the lab, we find it to be appropriate because of its inertness, biocompatibility, and porosity that enable excellent filtration capabilities.
However, it is not the only one. You can consider other electrospun polymers such as, Cellulose Acetate, PES, and PAN.