Diffusion in porous functional materials: Zeolite gas separation membranes, proton exchange membrane fuel cells, dye sensitized solar cells

The function of numerous technical apparatus and processes is diffusion controlled. In three cases studies, the diffusion of molecules, ions and electrons in gas separation membranes, fuel cell membranes and dye sensitized solar cells is discussed. In novel functional materials often an overlap of transport due to a concentration and/or a potential gradient takes place. The transport parameters measured in materials evaluation such as impedance spectroscopy can reflect a physical situation which is different from that of the working device. A detailed fundamental knowledge of various factors is necessary to fully understand the nature of transport as a basis to optimise the corresponding functional materials.