Formation mechanism and crystallization of poly(vinylidene fluoride) membrane via immersion precipitation method

Moreover, the thermal behavior and crystal structure of membranes prepared using different coagulation bath temperatures were examined by differential scanning calorimetry (DSC) and wide angle X-ray diffusion (WAXD). The results shows that the PVDF membrane precipitated at 60°C had a typical ''α'' form crystal structure. While at 15°C, the PVDF crystallites are a mixture of ''α'' and ''β'' form crystal structure. The crystallization degree of the prepared membrane has not increased with the coagulation bath temperature decreasing.