The objective of this work is to synthesize polystyrene based inorganic precipitated membranes and study the effects of non-uniform distributions of fixed charges on membrane potentials, i.e. having the same number of fixed charges with different distribution profiles. Similar to TMS theory, the membrane potential equation for linearly varying fixed charges was derived based on the Nernst-Plank flux equation and Donnan equilibrium. A numerical solution procedure was presented to obtain the membrane potential for uni-univalent electrolyte solutions. According to the simulation results, the effects of non-uniform distribution of fixed charges on membrane potential were discussed and the results were compared with the values obtained from TMS theory. This book has been divided into four chapters and conclusions. The First chapter contains introduction regarding membranes, their types, preparations and properties. The Second, Third and Fourth chapters deals with the synthesis, characterization, and membrane potential which has been measured across polystyrene based metal molybdate membranes separated by various 1:1 electrolytes at different concentrations.