Effect of functionalized graphene oxide nanosheets on the morphologies and antifouling properties of polyamide composite membranes

Abstract

The application of carbon‐based nanomaterials in desalination has attracted significant attention. In this study, the modified graphene oxide (GO) is prepared by the reaction of octylamine with the carboxyl groups of GO and is dispersed in (trimesoyl chloride)/n‐hexane solution using the phase inversion method. The polyaramide membrane is prepared via interfacial polymerization using aqueous solution of m‐phenylenediamine and modified GO/(trimesoyl chloride) in n‐hexane. The modified GO is found to be well dispersed in the n‐hexane solvent, which is confirmed by the atomic force microscopy method. The effect of modified GO on the chemical composition and morphology of the aramid membrane surface is studied via Fourier‐transform infrared spectroscopy‐attenuated total reflectance and scanning electron microscopy tests. The results of membrane performance show that the high water flux of the aramid membranes containing the modified GO is attributed to the porosity generation due to nanosheet protrusions and hydrophilic groups on the surface of modified GO. In addition, the increasing the salt rejection parameter can be the result of the interactions between the GO particles and the aramid chains during the interfacial polymerization. The fouling test results show that in the presence of the modified GO in aramid membrane, a hydrated layer of water can be formed on the surface of GO as a result of the presence of hydroxyl and epoxy groups. In high concentrations of modified GO, the presence of octyl hydrophobic agents leads to the ejection of the bovine serum albumin molecules from the membrane surface. J. VINYL ADDIT. TECHNOL., 23:E170–E179, 2017. © 2016 Society of Plastics Engineers