Executive Summary : | Ion-exchange membranes have high usage in chemical effluent treatments and energy device applications. They are integral part of new generation energy and water technology. The diffusion dialysis technology has been successfully used for acid recovery using anion-exchange membranes. But their inherent efficiency remains poor because of limited chemical and thermal stability in the highly oxidative environment of the effluents. Hence, we are proposing to develop new anion-exchange membranes for acid recovery from acidic effluents with intrinsic porosity and tuned charged density along with excellent chemical and thermal stability. The methodology involves the design of polymer and its conversion to membrane, followed by the design and assembly of a diffusion dialysis stack. Highly charged ion-exchange membranes were used as a separator for electrodes, across which ionic migration took place. But, generally mass transmission (water or fuel) also occurs along with ionic migration due to electro-osmotic drag, which reduces the membrane performance and efficiency during their use in energy and electrochemical devices. The properties of ion-exchange membranes such as membrane stabilities (thermal, mechanical and dimensional), water retention capability, ion-exchange capacity, water uptake and fixed group concentration, mass/water or ionic permeation (water and ionic transport numbers), membrane conductivity determine the efficiency, selectivity as well economics of practical applicability of ion-exchange membrane for energy or electrochemical devices. Thus, the preparation of chemically stable membrane in oxidative environments is of the utmost importance. |