| abstract |
A first irradiation takes place with particles having an inadequate energy to traverse the membrane (5), followed by a second irradiation from the other face (26) of the membrane (5) using also non-issuing particles and whose trajectories come into contact with those of the other particles. Chemical etching produces pores (respectively 33, 34), whereof some issue into other pores produced during the other irradiation. As the finest pore determines the filtering properties, the selectivity of this membrane is very good. |