PREPARATION OF ASYMMETRIC POROUS MATERIALS
As asymmetric porous film structure formed by depositing a porous material film on a flexible substrate, and applying an anisotropic stress to the porous media on the flexible substrate, where the anisotropic stress results from a stress such as an applied mechanical force, a thermal gradient, and an applied voltage, to form an asymmetric porous material.
1 . An asymmetric porous film structure, comprising:
a substrate;
a microporous film upon and in contact with the substrate;
wherein said substrate is anisotropically stressed producing asymmetric physical properties in the microporous film.
2 . The structure of claim 1 , wherein the porous film has a thickness between approximately 10 nm and 100 nm.
3 . The structure of claim 1 , wherein the substrate comprises a piezoelectric material.
4 . The structure of claim 1 wherein said substrate comprises a material selected from the group consisting of a glass material, a Si material, a metal, and a polymeric material.
5 . The structure of claim 1 , wherein said substrate is a shape memory alloy.
6 . The structure of claim 3 wherein said piezoelectric material is aluminum nitride.
7 . The method of claim 1 wherein said microporous film comprises a material selected from the group consisting of silica, alumina, aluminosilicate, titania, an organic material, and an organic-inorganic hybrid material.
8 . The structure of claim 1 wherein said microporous film comprises a zeolite.
9 . The structure of claim 1 , wherein said asymmetric physical properties comprise asymmetric pore structure.
10 . The structure of claim 1 , wherein said microporous film comprises chiral pores.
11 . The structure of claim 1 , wherein said microporous film is a chiral membrane.