Method for preparing polyvinyl alcohol gel based meshed polyvinylidene fluoride film

A method for preparing meshed polyvinylidene fluoride (PVDF) film based on a polyvinyl alcohol (PVA) gel, comprising: (1) mixing the PVA, a masking agent and a solvent in a certain mass ratio, stirring, heating at 105℃, and dissolving uniformly to obtain a PVA solution; (2) adding PVDF, a pore-forming agent, and the remaining supplementary solvent into the PVA solution, until the total quality score equals to 1, stirring and heating at 80℃, and dissolving uniformly the resulted solution to obtain a homogeneous casting solution; (3) the casting solution is filtered, deaerated , phase-separated and cured into a film A; (4) removing the PVA gel from film A, to get a film B; (5) washing the film B with water to remove the residual solvent, so as to obtain PVDF film of a meshed structure. The PVDF film is an asymmetric film with an ultrathin skin layer and an interpenetrating meshed sublayer structure, and the prepared film has better performance with regards to penetration among pores, flux, mechanical strength and the like.