Microporous membrane formation via thermally induced phase separation: Effect of temperature and evaporation time on membrane morphology

i-PP microporous membrane was prepared via thermally induced phase separation (TIPS) method. Diphenyl ether (DPE) was used as a diluent in this report. A microporous structure formed by evaporating the diluent from top of membrane and phase separation was obtained after solidification. The effects of temperature (413, 423 and 433 K) at bottom of samples and evaporation time (1, 3 and 5 min.) on the membrane morphology were investigated by scanning electron microscopy (SEM). SEM micrographs revealed cross sections for membrane prepared to use different evaporation times and temperatures. The difference in diluent concentration on both sides of membrane, forces the diluent to diffuse from inside to the outside of the membrane. Moreover, the amount of evaporated diluent enhances with increasing of evaporation time. The pore size becomes smaller with increasing of temperature at the bottom of the sample. In addition, with increasing of evaporation time, the pore size decreases

Keywords:

Thermally induced phase separation , Isotactic polypropylene , Microporous membrane