Fabrication of nonwoven polyester fabric supported grafted/crosslinked cellulose acetate reverse osmosis membrane for water desalination

The main objective of this work is to prepare cellulose acetate (CA) reverse osmosis (RO) membranes supported onto nonwoven polyester fabric to withstand the applied high pressure.The supported CA-RO membrane with a 250 µm was selected to investigate the surface modification by grafting n-isopropyl acrylamide (N-IPAAm) and crosslinking with N,N′-methylenebisacrylamide (MBAAm).The surface roughness of the modified grafted and crosslinked membranes were measured with different areas of 0.5 µm × 0.5 µm, 1 µm × 1 µm and 5 µm × 5 µm by atomic force microscope.Average roughness (R a ) values were decreased from 5.51 to 1.27 nm and 2.31 nm for the unmodified CA-RO, the grafted and grafted/crosslinked supported-CA-RO membranes, respectively.The performance of the fabricated supported CA-RO membranes was tested and proved the high stability to 30 bar.It was found that the salt rejections of pristine supported CA, 0.1% N-IPAAm grafted supported CA and 0.1 N-IPAAm/0.013%MBAAm/supported CA-RO membranes were 85.91%, 92.4% and 96.4%, respectively.Moreover, it was noticed that the water flux values were 6 L/m 2 h for the unmodified supported membrane, 3.89 L/m 2 h for the grafted membrane and 3.75 L/m 2 h for the crosslinked/grafted supported CA-RO membrane at 14 bar.