Abstract
The formation conditions of dynamic membranes were examined using polyethylenimine, carboxymethylcellulose, hydrous zirconium oxiside-polyacrylic acid and gelatine. In the case of reverse osmosis type membranes, except gelatine, the rejection of NaCl was found to be high when these dynamic membranes were formed in the pH range in which the viscosity of each polyelectrolyte was small. Membranes formation by adding NaCl caused increase of NaCl rejection, but this phenomenon was not observed at the minimum viscosity points of these polyelectrolytes. Furthermore the water contents of these dynamic membranes tended to decrease with increasing NaCl rejection.
In another case of filtration type membrane (gelatine), self-rejection was found to be high when gelatine dynamic membrane was formed in the range of pH under pH7. In the case of the feed solution containing NaCl at the running time, self-rejection decreased. Therefore, the repulsion between suport membrane and gelatine in solution, or between gelatine dynamic membrane and gelatine in solution should be considered as an important factor in membrane performance.
