Enhanced Performance of Asymmetric Polystyrene Membrane by Incorporation of Pluronic F127 and Its Application for Pervaporation Separation

Pervaporation is an efficient membrane process for liquid separation. The past decades had witnessed substantial progress and exciting breakthroughs in both the fundamental and application aspect of pervaporation. In the present study, the separation of aqueous alcohol solution through wet-phase inversion prepared polystyrene (PS) membrane was investigated by using the pervaporation process. The role played by Pluronic F127 as nonionic surfactant in the formation of PS membrane was also studied. Addition of surfactant in the casting solution can suppress macrovoids in polymeric membrane. The formation of asymmetric PS membranes was discussed in terms of the presence of surfactant in the casting solution and the PS concentration. The surface properties of the asymmetric PS membranes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The effects of polymer concentration, surfactant content, feed composition, and feed solution temperature on the pervaporation performance were evaluated. The separation factor towards water and the permeation rate for a 10 wt% aqueous ethanol solution through the asymmetric PS membrane with a 1.5 wt% Pluronic F127 was 39 and 140 g/m2 h.