Functionalized graphene-based material as a nanofiller for high-performance thin film composite seawater reverse osmosis membrane

ABSTRACT

This study aims to enhance the performances of existing thin film composite (TFC)-based seawater reverse osmosis (SWRO) membranes using sulfonated graphene oxide (SGO) embedded polysulfone (PSf) nanocomposite support membrane to prepare nanostructured TFC SWRO (nTFC-SWRO) membranes. The polyamide (PA) layer was coated on the SGO-based PSf support membrane (varying concentrations of SGO from 0.25 to 1.0 wt.%) through in situ interfacial polymerization technique using 1, 3-phenylene diamine in an aqueous solution and 1,3,5-benzene tricarbonyl trichloride in isobar-G solvent. Incorporating SGO in the PSf membrane shows increased porosity, tensile strength, and hydrophilicity in support which helps to enhance hydrophilicity, surface energy, and compaction resistance to the nanostructured TFC membranes. It was found that the optimum concentration (0.25 wt.%) of SGO-based SWRO membrane shows 63% increase in flux with marginal reduction of salt rejection compared to normal TFC-SWRO membrane when tested at 55 bar pressure and 32,000 ppm NaCl feed solution. SGO proves to be a promising nanofiller to develop high flux nanostructured TFC-SWRO membranes with enhanced performances comparable to GO-based thin film nanocomposite (TFN) membranes where nanofiller is embedded in the top PA layer and difficult to prepare in continuous coating machine.

GRAPHICAL ABSTRACT

KEYWORDS:

• Thin-film composite
• seawater reverse osmosis
• membrane
• sulfonated graphene oxide
• performance enhancement

Acknowledgments

The authors are appreciative to the Government of India’s Department of Atomic Energy for funding their research with a Research Fellowship. The authors are solely responsible for all of the concepts, viewpoints, findings, and conclusive statements that are presented and reported in this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Statement of novelty

This research provides very useful information about development of high flux thin-film composite seawater reverse osmosis (SWRO) membrane in a practical scale. This study aims to enhance the performances of existing thin film composite (TFC)-based SWRO membranes using sulfonated graphene oxide (SGO)-embedded polysulfone (PSf) nanocomposite support membrane to prepare nanostructured TFC SWRO (nTFC-SWRO) membranes. SGO proves to be a promising nanofiller to develop high flux nanostructured TFC-SWRO membranes with enhanced performances comparable to GO-based thin film nanocomposite (TFN) membranes where nanofiller is embedded in the top PA layer and difficult to prepare in continuous coating machine. SGO-based SWRO membranes are not available in the literature so far.