Preparation of asymmetric porous materials

Abstract

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.