- مبلغ: ۸۶,۰۰۰ تومان
- مبلغ: ۹۱,۰۰۰ تومان
The effect of evaporation process is investigated in the inversion of induced non-solvent phase in the poly system (ethylene alcohol-co-vinyl) (EVAL)/DMSO/ water. The duration of evaporation process is associated with membrane morphology resulting from the electron microscopy. Surprisingly, the evaporation time not only plays an important role in the creation of large pores, but also affects the membrane morphology from the sponge structure to the particle structure. The large pores are found in the membrane if the mold is immediately immersed in the water bath or the evaporation time is less than 15 minutes, while the large pores are reduced with the evaporation time of 30 minutes and the sponge structure is appeared. When the evaporation times are 45 and 60 minutes, a symmetrical membrane containing a packed bed of particles is observed with an equal diameter which is dominated by the solid-liquid separation process. This indicated that the polymer crystallization of EVAL from the evaporated solution prevents the formation of asymmetric membrane with cell pores dominated by liquid-liquid separation process. A crystallization process depends on the depth of solid-liquid separation region compared to the corresponding phase diagram. The results of the study showed that the membrane structure can be well controlled by understanding the mechanism of membrane formation.