Fabrication of novel heterogeneous cation exchange membrane by use of synthesized carbon nanotubes-co-copper nanolayer composite nanoparticles: Characterization, performance in desalination

• Novel PVC/MWCNT–co-Cu composite nanoparticle membranes were prepared.
• Selectivity was improved by an increase of composite nanoparticles content.
• Flux was declined by an increase in nanoparticles concentration and then increased.
• Electrical resistance was decreased sharply with the use of composite nanoparticles.
• Mechanical stability improved by use of MWCNT–co-Cu composite nanoparticles.

In this research polyvinyl chloride/multi walled carbon nanotube–co-copper nanolayer composite nanoparticles heterogeneous cation exchange membranes were prepared by solution casting techniques. The MWCNT–co-Cu nanolayer composite nanoparticles were prepared by magnetron sputtering method. The effect of composite nanoparticle concentration on physico-chemical properties of membranes was studied. The SEM, TEM and XRD results showed uniform distribution and crystalline structure for the deposited Cu nanolayer on the MWCNTs' surface. SOM images also showed relatively uniform particle distribution for the membranes. The membrane potential, transport number, selectivity and electrical conductivity were improved by an increase of additive content in prepared membranes. Membrane average roughness was decreased slightly by an increase of additive concentration. Membrane ionic permeability and flux were decreased initially by an increase of additive ratio up to 0.5 wt.% and then showed an increasing trend by more additive concentration. Furthermore, mechanical stability of prepared membranes was improved by an increase of MWCNT–co-Cu nanolayer composite nanoparticle content in membrane matrix. Also, modified membrane containing 4 wt.% composite nanoparticles showed better electrochemical properties compared to other modified membranes, membrane containing pure MWCNTs and unmodified ones.