Preparation of novel cross-linked graphene oxide membrane for desalination applications using (EDC and NHS)-activated graphene oxide and PEI

A novel cross-linked graphene oxide (GO) membrane was prepared by vacuum filtration using a two-step method, including activation of GO carboxyl groups by a mixture of 1-Ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDC) and N -Hydroxysuccinimide (NHS) and then cross-linking with polyethyleneimine (PEI). In the cross-linking process, the activated carboxyl groups of GO react with amine groups of PEI through a simple and efficient method. GO cross-linking with PEI significantly improves membrane dimensional stability and salt rejection. The rejection of the cross-linked GO membrane was evaluated by NaCl, Na2SO4 and MgCl2 solutions, and the obtained results followed the order of R (MgCl2) > R (NaCl) > R (Na2SO4). The prepared cross-linked GO membrane was characterized by FTIR, XRD, SEM, FESEM, EDS, WCA, AFM and BET analysis. Also, the effects of operating parameters such as N2 pressure, feed temperature and pH on the cross-linked GO membrane performance were investigated.