The effects of membrane preparation conditions on morphology of PVDF/PES/CA blend membranes

Membranes were prepared by the phase inversion method from 9:1 polyvinylidene fluoride (PVDF)/polyethersulfone (PES) (here 9:1 means PVDF/PES weight ratio) with different acetate (CA) content, where PEG 10000 was used as pore forming agent. Different membrane preparation conditions, i.e. CA content, pre-evaporated time and consistence of coagulation bath, were studied to show their influence on the characteristics and performance of PVDF / PES / CA blend membranes. Membrane performance was evaluated by shrinkage ratio, porosity ratio, pure water flux and retention to bovine serum albumin (BSA). PVDF/PES/CA blend membranes prepared from the mixture ratio PVDF / PES / CA =9/1/0.8 has not only the lowest shrinkage ratio but also highest water flux and retention to BSA. In various pre-evaporated time of the membrane, the time 45s has the highest water flux and lowest retention ratio, and time 30s has better water flux and better retention ratio than other time. The water flux of the blend membrane decreases and the retention ratio of the blend membrane increases with increasing of DMAc concentration in coagulation bath.