나노 구조물을 이용한 농도 차 발전 시스템에 관한 연구

Ion selective alumina membranes and silica-coated membranes are studied to generate electric power from a concentration gradient by reverse electrodialysis. The surface in alumina membranes is usually positively charged when contacting an electrolyte. In alumina membranes, pore interior has higher positive ions than negative ions. On the other hand, the surface in alumina membranes with silica coating is usually negatively charged when contacting an electrolyte. Consequently, alumina membranes are ionic selective for positive ions and silica-coated membranes are ionic selective for negative ions. It is much easier to manufacture the porous membranes than ion exchange membranes. When an electrolyte concentration gradient is applied between the membranes, electric power is generated. Experimental investigation is conducted for the power generation from these alumina membranes and silica-coated membranes placed between two sodium chloride solutions with constant concentration ratio. Ion selectivity of alumina membranes and silica-coated membranes is constant as concentrations of the solutions increase. Due to relatively easy and low cost fabrication processing of alumina membranes, power generation from concentration gradients with alumina membranes could be widely used in a various application area.