Study On Noel Ion Exchange Membrane For Reverse Electrodialysis

As a clean,sustainable,non-pollution and high energy density technology,reverse electrodialysis(RED)has been applied in many aspects.The electrochemical and physical chemistry properties of ion exchange membrane,the core component of the RED system,determine the power generation performance of RED This paper has manufactured a new ion exchange membrane and investigated its RED power generation performance.Simultaneously,the porous conductive membrane has some advantages,such as good hydrophilicity,anti-pollution,compressive,good resistance of acids and alkali,antimicrobial and bacteria,low resistance.This paper explores the conductive properties of several UF membranes with different materials and aperture,tests the membrane resistance and membrane potential in NaCl solution and investigates the membrane separation performance with the contact angle,Zeta potential and scanning electronic microscopy.The results show that the resistance of porous membrane in 0.1 M NaCl solution is much lower than in 0.01 M NaCl solution,as low to 2.47?·cm~2.The porous membranes of different materials have the lower resistance with higher hydrophilicity.While the resistance of same materials porous membranes decrease with the aperture become larger,such as UN50(2.69?·cm~2)and UN100(2.47?·cm~2).The selected PAN50 membrane was modified using layer-by-layer(LbL)assembly deposition.The effects of deposition method,deposition number,supporting salt concentration and test solution concentration on the resistance and membrane potential of modified anion exchange membrane was investigated.The pressure deposition process and absorption deposition process were compared,and the membrane resistance is not of much difference.But the permselectivity of membrane modified by pressure deposition process is better.The modified membrane potential of 0.5 layers is the minimum,which is-6.4 mV,improving the selection of anion.With the increase of concentration of support salt,the membrane resistance decreased to 2.77?·cm~2 and the membrane potential decreased to-6.75 mV.When the concentration of the test solution increased from 0.05 M to 0.5 M,the membrane resistance decreased from 16.66?·cm~2 to 1.08?·cm~2,which was lower than that of the commercial ion exchange membrane under the same test conditions.A mathematical model of the RED generation process was set up.The influence of membrane permselectivity and membrane resistance against the solution composition was investigated.The output power density of RED increased with ion exchange membrane resistance decreased and the permselectivity increased.The net power density of RED using modified membranes is 0.228 W/m~2,which is less than using commercial mermbranes.Due to the low permselectivity of porous modified membrane.So the permselectivity of the modified membrane still needs to be further improved.