Chitosan and polyethylene glycol (PEG-600) membranes were synthesized and crosslinked with 3-aminopropyltriethoxysilane (APTES). The main purpose of this research work is to synthesize RO membranes which can be used to provide desalinated water for drinking, industrial and agricultural purposes. Hydrogen bonding between chitosan and PEG was confirmed by displacement of the hydroxyl absorption peak at 3237 cm−1 in pure chitosan to lower values in crosslinked membranes by using FTIR. Dynamic mechanical analysis revealed that PEG lowers Tg of the modified membranes vs. pure chitosan from 128.5 °C in control to 120 °C in CS-PEG5. SEM results highlighted porous and anisotropic structure of crosslinked membranes. As the amount of PEG was increased, hydrophilicity of membranes was increased and water absorption increased up to a maximum of 67.34%. Permeation data showed that flux and salt rejection value of the modified membranes was increased up to a maximum of 80% and 40.4%, respectively. Modified films have antibacterial properties against Escherichia coli as compared to control membranes.

Solution casting method was used to synthesize chitosan (CS)-based membranes for reverse osmosis (RO) using PEG-300 and tetraethylorthosilicate as a crosslinker. Their salt rejection (%) and permeate flux (mL/h.m 2 ) was measured by using lab scale RO plant. FTIR spectroscopy reveals interactions between CS and PEG by shifting of OH peak from 3237 cm −1 to lower wavenumber in modified membranes. SEM results showed pores in modified membranes while pure CS membranes had uniform nonporous and dense microstructure. DMA results demonstrated that the addition of PEG lowers the T g value up to 6.5%. Water content of membranes increases up to 82.63% as the amount of PEG increases owing to its hydrophilic nature. The bacterial killing ability showed that the modified membranes possess good antibacterial activity against Escherichia coli in comparison to the control film. The permeation results revealed that salt rejection and flux of the modified membranes increased up 60% and 86.36 mL/h.m 2 , respectively.