Fabrication of layer-by-layer ion exchange membrane by applying PDA-POSS nanocomposite onto heterogeneous cationic substrate for water treatment

Double layer Cation Exchange Membranes (DLCEMs) have been prepared by surface polymerization of dopamine-co-POSS nanoparticles on a PVC based heterogeneous cation exchange membrane. FTIR and FESEM images proved relatively uniform forming of intended DLCEMs. The FESEM images illustrated almost integrity dispensation of nanoparticles through the surface layer. Results represented that developing nanocomposite layer resulted in surface hydrophilicity enhancement. The obtained data for Cu۲+ and Cr۲+ removal percentage for the prepared membranes represents higher capacity for DLCEMs to remove heavy metals compared to pristine cationic membrane. Also membranes showed higher Cr۲+ removal capacity rather than Cu۲+. The membrane surface modification by introducing PDA nanocomposite also caused to improving sodium permeability and flux. Furthermore, transport number and permselectivity of the prepared CEMs generally follow an increasing procedure nearly. It should be noticed that incorporation of POSS nanoparticles into the surface layer resulted in electrical resistance reduction obviously.

Keywords:

Electrodialysis , Double layer Membrane , Electrochemical characterization , Water treatment