Mesoporous filter

Abstract

A particulate filter is provided for passing through select permeate particles in a fluid medium from inflow to outflow regions while restraining reticulate particles. The filter includes a coarse-grain ceramic porous substrate, an intermediate-grain porous ceramic layer, a fine-grain ceramic porous membrane, and a channel there-through. The substrate opens into the outflow region as an outflow cavity. The intermediate-grain porous ceramic layer is disposed on the substrate. The fine-grain ceramic porous membrane is disposed on the layer and opens into the inflow region containing the medium as an inflow cavity. The channel directionally expands and connects the inflow and outflow cavities together by a substantially funnel-shape passage. The inflow cavity permits the permeate particles and the medium but obstructs the reticulate particles. Additionally, a method is provided for producing a particulate filter that passes through select permeate particles in a fluid medium from inflow to outflow regions while restraining reticulate particles. The method includes providing an aluminum oxide substrate, disposing a sol-gel membrane onto the substrate to form a filtration unit, drying the filtration unit, and calcinating the filtration unit.

1. A particulate filter for passing through select permeate particles in a fluid medium from inflow to outflow regions while restraining reticulate particles, said filter comprising:
 a coarse-grain ceramic porous substrate that opens into the outflow region as an outflow cavity;  
 an intermediate-grain porous ceramic layer disposed on said substrate;  
 a fine-grain ceramic porous membrane of zirconium oxide disposed on said layer and that opens into the inflow region containing the medium as an inflow cavity, said membrane having pore diameters between 5Å and 50Å; and  
 a channel that directionally expands and connects said inflow and outflow cavities together by a substantially funnel-shape passage, wherein said inflow cavity permits the permeate particles and the medium but obstructs the reticulate particles.  
 
     
     
       2. The filter according to  claim 1 , wherein said substrate is one of α- aluminum oxide, γ-aluminum oxide and zirconium oxide. 
     
     
       3. The filter according to  claim 1 , wherein said substrate is α-aluminum oxide, and said layer is γ-aluminum oxide. 
     
     
       4. The filter according to  claim 1 , wherein said substrate is γ-aluminum oxide having pore diameter of about 50Å. 
     
     
       5. The filter according to  claim 1 , wherein said substrate is zirconium oxide having pore diameter of about 200Å. 
     
     
       6. The filter according to  claim 1 , wherein said substrate is α-aluminum oxide and said layer is silicon oxide. 
     
     
       7. The filter according to  claim 1 , wherein filter is a cylindrical tube having an annular interior for said inflow region.