Cerium oxide doped nanocomposite membranes for reverse osmosis desalination

Abstract

Cerium oxide (CeO2) nanoparticles (NPs) have indicated great potentials as nanofiller owing to its high surface area, antioxidant properties and low cost. In this paper, thin film nanocomposite (TFN) RO membranes were proposed to be prepared through incorporation of hydrophilic CeO2 NPs in polyamide (PA) selective layers via interfacial polymerization (IP). EDX, XPS, SEM, AFM, contact angle and zeta potential were used to examine the property and morphology of the prepared membranes. CeO2 NPs were successfully embedded in the PA network, which endowed the TFN membranes with rougher surfaces and thinner PA layers. The TFN membranes were fabricated with different CeO2 NPs contents (0, 50, 100, 150, 200, 400 mg/L). With increasing CeO2 NPs loading amount, the hydrophilicity improved from 85.4° to 65.7° and the surface charge declined from -19.4 to -34.2 mV. These characteristics contributed to a 50% enhancement in water flux of TFN-CeO2100 membrane (containing 100 mg/L of CeO2 NPs) without compromise the NaCl rejection (98%). Moreover, CeO2 embedded membrane exhibited an enhanced fouling resistance property through preventing the adhesion of hydrophobic foultants. This study demonstrated the desirable applicability of CeO2 NPs in synthesizing novel TFN membranes for desalination application.