In the present study, mixed matrix PES/zeolite nanoparticles nanofiltration membranes were prepared via the solution casting technique. The effect of zeolite concentration on the PES membrane performance and its properties was studied. Cross-sectional scanning electron microscope (SEM) observations showed that the porosity in the membrane sub-layer was increased with addition of zeolite into the casting solution. Surface SEM images and scanning optical microscope (SOM) images showed the nanoparticles agglomeration in the surface at high loading rates. Membrane roughness was decreased with the addition of zeolite into the casting solution. Results indicated that the membrane water content was improved initially by using 0.05 wt. % zeolite nanoparticles and then was decreased with further increase in additive concentration. Utilizing zeolite nanoparticles in the casting solution also led to decrease of surface contact angle from 62.02° for PES membrane to 36.87° for membrane filled with 0.1 wt.% zeolite. Moreover, water flux and tensile strength were enhanced with addition of the zeolite (up to 0.1 wt. %) and then were decreased whereas the rejection was decreased just in 0.1 wt. % nanoparticles loading rate. The flux reduction ratio of the prepared membranes was also estimated. Mixed matrix PES/zeolite membranes showed better antifouling properties compared to the PES one.
