Effects of L-lysine-conjugated-graphene oxide as a nanofiller on the CO2 separation performance of mixed matrix chitosan membrane

Abstract

ABSTRACT Advanced membrane materials with higher gas separation capabilities have developed a lot of interest in CO2 separation because of their ease of fabrication, low cost and excellent separation performance. Amino acid surface modification of fillers is an efficient approach for improving the bond between the polymer and the fillers. We created MMMs in the Chitosan (CS) matrix using L-lysine functionalised graphene oxide (f-GO) nanosheets. The current research focuses on the many elements of chemical conjugation of L-lysine onto graphene oxide utilising carbodiimide as a coupling agent for CO2/N2 separation. FTIR, XRD, Raman, TGA, AFM, FESEM, contact angle and water uptake tests were used to investigate the physicochemical characteristics of the produced GO, Lys-c-GO and Lys-c-GO embedded chitosan membranes. A defect-free dense layer with an active layer thickness of 5 µm was successfully cast on a PES support and used for a mixed gas (CO2/N2) separation research at temperatures ranging from 25 to 105 degrees Celsius under swelling circumstances. By maintaining a sweep/feedwater flow rate ratio of 1.5 at an optimal operating temperature of 95°C and feed absolute pressure of 1.21 bar, the fabricated membrane demonstrated strong CO2 permeance and CO2/N2 selectivity.