Impact of Graphene Oxide on Properties and Structure of Thin-Film Composite Forward Osmosis Membranes

Abstract

Forward osmosis (FO) membranes have the advantages of low energy consumption, high water recovery rate, and low membrane pollution trend, and they have been widely studied in many fields. However, the internal concentration polarization (ICP) caused by the accumulation of solutes in the porous support layer will reduce permeation efficiency, which is currently unavoidable. In this paper, we doped Graphene oxide (GO) nanoparticles (50~150 nm) to a polyamide (PA) active layer and/or polysulfone (PSF) support layer, investigating the influence of GO on the morphology and properties of thin-film composite forward osmosis (TFC-FO) membranes. The results show that under the optimal doping amount, doping GO to the PA active layer and PSF support layer, respectively, is conducive to the formation of dense and uniform nano-scale water channels perpendicular to the membrane surface possessing a high salt rejection rate and low reverse solute flux without sacrificing high water flux. Moreover, the water channels formed by doping GO to the active layer possess preferable properties, which significantly improves the salt rejection and water permeability of the membrane, with a salt rejection rate higher than 99% and a water flux of 54.85 L·m−2·h−1 while the pure PSF-PA membrane water flux is 12.94 L·m−2·h−1. GO-doping modification is promising for improving the performance and structure of TFC-FO membranes.

Effect of Polydopamine/Sodium Dodecyl Sulfate Modified Halloysite on the Microstructure and Permeability of a Polyamide Forward Osmosis Membrane

“…The ideal permeability can be obtained by the modification of the active layer and supporting layer, respectively. Researchers have optimized film nanocomposites by adding hydrophilic nanomaterials to the support layer or by adding monomer solutions (such as an MPD aqueous solution or a TMC/hexane solution) to the active layer [ 11 , 12 , 13 ]. The hydrophilicity of the support layer can be improved by selecting materials with good hydrophilicity and by surface modification of the support layer [ 14 ].…”