Nanoporous filter
A nanoporous filter comprises a porous support having an essentially flat surface on which is deposited a nanoporous layer having a substantially regular pore structure and uniform pore size within the range from 1 to 50 nm.
1. A nanoporous filter comprising a porous support having an essentially flat surface, on which is deposited a metal nanoporous layer having a substantially regular pore structure, and uniform pore size within the range from 1 to 50 nm.
2. A filter according to claim 1 , in which said pore size is from 1 to 20 nm.
3. A filter according to claim 2 , in which the pore structure of the nanoporous layer is cubic, lamellar, oblique, centred rectangular, body-centred, orthorhombic, body-centred tetragonal, rhombohedral or hexagonal.
4. A filter according claim 2 , in which the nanoporous layer comprises platinum, palladium, gold, silver, nickel, cobalt, copper, iron, lead, tin or indium.
5. A filter according to claim 4 , in which the pore structure of the nanoporous layer is cubic, lamellar, oblique, centred rectangular, body-centred, orthorhombic, body-centred tetragonal, rhombohedral or hexagonal.
6. A filter according to claim 1 , in which said pore size is from 1.5 to 12 nm.
7. A filter according to claim 6 , in which the pore structure of the nanoporous layer is cubic, lamellar, oblique, centred rectangular, body-centred, orthorhombic, body-centred tetragonal, rhombohedral or hexagonal.
8. A filter according to claim 6 , in which the nanoporous layer comprises platinum, palladium, gold, silver, nickel, cobalt, copper, iron, lead, tin or indium.
9. A filter according to claim 8 , in which the pore structure of the nanoporous layer is cubic, lamellar, oblique, centred rectangular, body-centred, orthorhombic, body-centred tetragonal, rhombohedral or hexagonal.
10. A filter according to claim 1 , in which the pore structure of the nanoporous layer is cubic, lamellar, oblique, centred rectangular, body-centred, orthorhombic, body-centred tetragonal, rhombohedral or hexagonal.
11. A filter according to claim 1 , in which the pore structure is hexagonal.
12. A filter according to claim 1 , in which the nanoporous layer comprises platinum, palladium, gold, silver, nickel, cobalt, copper, iron, lead, tin or indium.
13. A filter according to claim 12 , in which the nanoporous layer comprises platinum, palladium or nickel.
14. A filter according to claim 12 , in which the nanoporous layer comprises platinum or palladium.
15. A filter according to claim 1 , in which the nanoporous layer is from 5 nm to 1 μm thick.
16. A filter according to claim 1 , in which the nanoporous layer is from 5 nm to 1 μm thick, in which the pore structure of the nanoporous layer is cubic, lamellar, oblique, centred rectangular, body-centred, orthorhombic, body-centred tetragonal, rhombohedral or hexagonal and in which the nanoporous layer comprises platinum, palladium, gold, silver, nickel, cobalt, copper, iron, lead, tin or indium.
17. A filter according to claim 1 , in which the nanoporous layer comprises a transition metal.
18. A method of preparing a nanoporous filter according to claim 1 by depositing a metal nanoporous layer having a substantially regular pore structure and uniform pore size within the range from 1 to 50 nm onto a porous support having an essentially flat surface from an essentially homogeneous lyotropic liquid crystalline phase comprising a solvent, an organic directing agent and a source of the material of the nanoporous layer.
19. A method according to claim 18 , in which the solvent is water.
20. A method according to claim 18 , in which the organic directing agent is a surface active agent.
21. A method according to claim 19 , in which the organic directing agent is a surface active agent.