Faezeh Moradi - Department of Chemical Engineering, Faculty of Engineering, Arak University,Arak ۳۸۱۵۶-۸-۸۳۴۹,Iran
Samaneh Koudzari Farahani - Department of Chemical Engineering, Faculty of Engineering, Arak University,Arak ۳۸۱۵۶-۸-۸۳۴۹,Iran
Seyed Mohsen Hosseini, - Department of Chemical Engineering, Faculty of Engineering, Arak University,Arak ۳۸۱۵۶-۸-۸۳۴۹,Iran
Ehsan Bagheripour - Department of Chemical Engineering, Faculty of Engineering, Arak University,Arak ۳۸۱۵۶-۸-۸۳۴۹,Iran

In this research, the polymeric NF membrane based on polyethersulfone (PES) was prepared using polyvinylpyrrolidone as cavitation and dimethylacetamide as a solvent by phase inversion method. The combination of chitosan with various ratios of carbon nanofibers was placed on the membrane surface using the immersion method. The effect of surface modification on the hydrophilic behavior of prepared membranes was studied. More hydrophilicity of the membrane surface improves the flux and antifouling performance. The results show that with the surface modification, the contact angle for all membranes decreased relative to the base membrane. The base membrane has the largest contact angle (62.66), indicating the nature of the PES hydrophobic. The water contact angle for M2 membrane remarkably decreases. Chitosan is a chitin product and is a hydrophilic polymer. Chitosan has hydroxyl (–OH) and amine (–NH2) groups. Chitosan is widely used as a material for membrane applications due to its hydrophilic nature [1-2]. Deposition of the chitosan on the membrane surface increases the number of hydrophilic functional groups (–OH and – NH2). So, the hydrophilic nanoparticles enhance water absorption in the top surface of the membrane. Also, carbon nanofibers, by filling the cavities on the surface of the membrane, create a smooth surface, which also increases the hydrophilic of the membrane surface. In sample M3, the water contact angle increased again. However, although water absorption increases by increasing the nanoparticles concentration, an excessive amount of nanoparticles can fill the free volumes of the top surface, leading to an increase of the water contact angle (47.71).