Preparation and Characterization of PES-Blend-Sulfonated PVC Nanofiltration Membranes: Investigation of Polymers Blend Ratio

Polyethersulfone (PES)/sulfonated polyvinyl chloride (SPVC)-blend membranes were prepared by commonly phase inversion method and casting solution technique, and polyvinylpyrrolidone was used as a pore former in the casting solution. PES/SPVC nanofiltration membranes with different polymer ratios were prepared and characterized by scanning electron microscopy (SEM), porosity measurement, water content, tensile strength and dead-end filtration experiments (permeability flux and salt rejection). SEM images showed an asymmetric structure with a dense top layer and porous sub-layer for all of the prepared membranes. Membrane porosity was increased with increasing of SPVC content of the casting solution. Adding SPVC into the casting solution led to increasing of membrane water content, pure water flux, permeation flux and pore size compared to bare PES membrane. By increasing of SPVC content (5 wt%), an initial improvement was observed in the rejection, and then, it diminished. Tensile strength was also enhanced initially by the addition of SPVC into the casting solution and again decreased.