Poly(aryl ether sulfone sulfide)/flower‐like ZnO nanocomposites: Synthesis, characterization and application as water treatment membrane

Abstract

In this research, poly(aryl ether sulfone sulfide) was synthesized by nucleophilic aromatic substitution reaction of 4,4′‐thiodiphenol with 4,4′‐dichlorodiphenyl sulfone in the presence of potassium carbonate. Also, flower‐like zinc oxide nanoparticles were synthesized through sol–gel route and then added in various percentages to poly(aryl ether sulfone sulfide) matrix to modify its hydrophobic nature. The chemical structure of the polymer was confirmed using Fourier transform infrared and proton nuclear magnetic resonance spectroscopy. For investigation of thermal properties of the samples, differential scanning calorimetry and thermogravimetric analysis were applied. Hydrophilicity of the membranes was also studied via contact angle measurement. Morphology of membranes and distribution of flower‐like zinc oxide nanoparticles that were followed by scanning electron microscopy and transmission electron microscopy showed asymmetric structure with porous sub‐layer and dense skin layer. Pure water flux, salt rejection, and flux recovery ratio also were investigated using cross‐flow filtration system with NaCl as a feed solution. Effect of zinc oxide on polysulfone matrix was studied. The results showed that presence of ZnO modified the mechanical and thermal properties of samples. Maximum pure water flux (61 L m−2 h−1), salt rejection (63.6%), and flux recovery ratio (77.6%)were related to the sample with 3 wt% zinc oxide.