method of preparation of hyperfiltrantes membranes, in particular for the decelement total water and sea, and conducted by the application of the membrane method

摘要

Semipermeable membrane for reverse osmosis is produced from a matrix of plastic material which is itself impermeable towards the liquid and has an originally inhomogeneous structure with at least two chemically similar layers having a different microstructure. The layers possess different suit abilities for conversion into an ultrafiltering membrane, one layer having a lower retention property and a higher flow rate and the other layer having a higher retention property and a low thickness so that the flow rate in the membrane is not considerably lowered. Esp. useful for treating sea water. The membrane retains dissolved salts and allows a high flow rate of dimineralised water without requiring the use of high pressures. The membrane has a good chemical resistance.