The Effect of Functional Carbon Nanotubes in Permeability of Ultrafiltration Nanocomposite Polyvinylidene Fluoride (PVDF) Membrane

In this paper, flux and antifouling performance of PVDF (15wt.%) nanocomposite ultrafiltration mambrane with different functionalized carbon nanotubes (-COOH, -OH, -NH2) are considered. Membranes are prepared with phase inversion method using NMP as solvent. This is the first time that hydrophilicity of different nanocomposite membranes are changing gradually as performance of nanocomposite membrane are considered. Gradually, the change of hydrophilicity explaines the behavior and performance of nanocomposite membrane. Analysing surface pore size by SEM showed no significant diffferent in mean pore size (a few tenths of a micron) of nanocomposite memebranes in comparison with pristine memebrans. The cross section morphology showed that all prepared membranes are asymmetric structure with a compact toplayer and a bottom layer with large pore channels. All modified nanocomposite membranes show better hydrophilicity surface in comparison with pristine PVDF membrane (87°). The results of pure water flux are approved by the results of contact angle and porosity which have been measured. Pure water flux of nanocomposite membranes with optimized carbon nanotube amount is increased more than twofold to pristine membrane (146 L/m2.h). AFM also revealed that nanocomposite membranes have smaller roughness in comparison with pristine membrane (Sa=270 nm). This subject is shown that functional carbon nanotubes have not any detrimental effects on mechanical resistance in modified membranes.