Preparation and electrochemical characterization of polyvinylchloride/FeTiO3-co-Fe3O4 nanoparticles mixed matrix ion exchange membranes: Investigation of concentration and pH effects

摘要

Polyvinyl chloride based/FeTiO3-co-Fe3O4 nanoparticles mixed matrix heterogeneous cation exchange membranes were prepared by solution casting technique. The effect of using filler additives in casting solution and also electrolyte concentration and pH on electrochemical properties of membrane was studied. Membrane potential, transport number and selectivity were improved by using FeTiO3-co-Fe3O4 nanoparticles in membrane matrix. Utilizing FeTiO3/ Fe3O4 nanoparticles in membrane matrix also led to improvement of membrane ionic flux from 2.95*10(-5) to 4.15*10(-5) (mol/m(2)center dot s) obviously. Similar trend was also found for membrane electrical conductivity. Moreover, the transport number, selectivity and membrane electrical conductivity were enhanced by increase of electrolyte concentration. Prepared membranes exhibited higher transport number/selectivity at pH 7 compared to other pH values. Obtained results showed that the membrane electrical resistance decreased initially by increase of electrolyte pH sharply and then began to increase. Membranes exhibited lower selectivity for bivalent ions compared to monovalent type. Modified membranes containing FeTiO3-co-Fe3O4 nanoparticles showed more appropriate electrochemical properties compared to other prepared membranes.