摘要:
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.
摘要:
Process for the production of asymmetrical microporous membranes by double irradiation.A membrane (5) is exposed to two irradiations, whereof one has an inadequate energy level to pass through the same, whereas the other passes through membrane (5).The irradiations produce molecular defects, which are attacked or etched in preferred manner by certain chemical agents. Thus, two networks of pores are obtained, one network being of large diameter and of a non-issuing nature (26), the other being smaller (27, 28, 29) and which issue on to the two surfaces (31, 32) of membrane (5).Application to filtration and sterilization.
摘要:
The invention relates to the production of films having in their thickness at least two superimposed zones, including a semimetallic zone and an electrically insulating zone, by irradiating a polymer film by means of a high energy ion beam.It is possible by this process to produce semimetal (1)/insulant (2)/semimetal (3) structures by irradiating the polymer under vacuum by means of light ions or with a limited stopping power having an energy of at least 1 MeV/amu. It is also possible to obtain insulant (4)/semimetal (5)/insulant (6) structures by irradiating, in a confined atmosphere, the polymer by means of heavy ions or ions having a high energy loss with an energy of at least 1 MeV/amu.By irradiating only certain zones of the film, it is thus possible to form embedded or surface-positioned electrical connections.
摘要:
The invention relates to the production of films having in their thickness at least two superimposed zones, including a semimetallic zone and an electrically insulating zone, by irradiating a polymer film by means of a high energy ion beam.It is possible by this process to produce semimetal (1)/insulant (2)/semimetal (3) structures by irradiating the polymer under vacuum by means of light ions or with a limited stopping power having an energy of at least 1 MeV/amu. It is also possible to obtain insulant (4)/semimetal (5)/insulant (6) structures by irradiating, in a confined atmosphere, the polymer by means of heavy ions or ions having a high energy loss with by energy of least 1 MeV/amu.By irradiating only certain zones of the film, it is thus possible to form embedded or surface-positioned electrical connections.