Ethylene-vinyl alcohol (EVAL) membranes with particles-bonded structure are prepared by phase inversion from DMSO solvent into the coagulation baths of water and isopropanol (IPA) mixture. It is based on controlling the relative diffusion rate of solvent to nonsolvent and the liquid-liquid demixing area. Using this analysis, it can explain the effects of adding IPA to the water bath on the formation of particles and the suppression of macrovoids. The results proposed here are believed to be valid also for other systems.