Assessing the properties of thin-film nanocomposite membrane embedded with GO nanosheets using the DSPM-DE model

Abstract

In this work, the effect of embedding graphene oxide (GO) nanosheets into the polyamide (PA) layer of thin-film nanocomposite (TFN) membrane properties, including the pore radius (rp), pore dielectric constant (εp), and charge density (Xd), was studied by applying Donnan-steric-pore-model-dielectric-exclusion (DSPM-DE) model. A TFN membrane was fabricated via interfacial polymerization by dispersing GO in an aqueous m-phenylenediamine solution. Characterizations using atomic force microscopy, zeta potential and contact angle of fabricated TFN membrane showed a smooth surface, a high negative surface charge and hydrophilic nature. X-ray photoelectron spectroscopy and Fourier transform infrared analyses confirmed the incorporation of GO in the PA layer of the TFN membrane. The Supply–Demand-Based Optimisation (SDO) algorithm was applied as an appropriate technique to fit experimental values of NaCl rejection with the DSPM-DE model to predict membrane properties. The SDO algorithm showed an excellent agreement between experimental data and the DSPM-DE model and the ability to predict accurate values of TFN membrane characteristics. The obtained results indicate no significant effect of GO nanosheets on the pore radius of the PA layer. The Xd of membranes increased toward negative with NaCl concentration due to adsorbing chloride ions onto the membrane surfaces. The Xd increase in TFN membrane was more because of GO presence; thereby TFN membrane performance improved. The εp value of the solution inside pores for the TFC membrane decreased more than the TFN membrane.