ASYMMETRICAL TRACK-ETCHED MEMBRANE AND PROCESS OF ITS PRODUCTION Russian patent published in 2008 - IPC B01D67/00 B01D71/06 

FIELD: physics.

SUBSTANCE: asymmetrical track-etched membrane includes two systems of calibrated pores of different depth. The pores have isotropic tilt in the film depth due to irradiation of the film by heavy charged particles under different angles. The pores of both systems have multiple intersections. Penetration depth for branched cross-cut pore structure does not exceed pore length for the system with the largest pore diameter. Process of asymmetrical track-etched membrane production involves irradiation of polymer film, UV processing of film and further etching. Irradiation is conducted simultaneously by two groups of heavy nucleus fission fragments with different mass and track length in the irradiated polymer. Polymer film depth is not less than average track length for fission fragments with larger mass, and not more than average track length for fission fragments with smaller mass in the given polymer.

EFFECT: increase in efficiency of membrane without change to its selectivity and mechanical strength.

7 cl, 3 dwg, 5 ex