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US 8,556,088 B2Granted
Nanoporous oxide ceramic membranes of tubular and hollow fiber shape and method of making the same
AssigneeKorea Electrotechnology Research Institute
InventorDae Yeong Jeong
Life of this patent
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Abstract
The present invention is aimed to fabricate nanoporous anodic oxide ceramic membrane tubes with excellent pore characteristics by anodizing metal tubes located in a cylindrical symmetry with respect to a cathode which itself has a cylindrical symmetry. The membrane tubes may have protruded portions acting as supports and joints. The present invention also deals with stacks and bundles consisted of numbers of the anodic oxide ceramic tubes for filter and dialysis applications.
Claims7
A method of producing a nanoporous oxide ceramic membrane comprising:
- providing a metallic tube in a tubular or hollow fiber shape of predetermined dimension;
- placing a cathode inside the metallic tube in cylindrical symmetry to each other;
- placing a heat sink in contact or in close contact with an outer wall of the metallic tube so as to sufficiently absorb heat generated during anodization and to make the anodization process proceed in a steady state;
- filling an electrolyte to soak an inner wall surface of the metallic tube and the cathode with the electrolyte;
- and
- anodizing the metallic tube to produce a nanoporous oxide ceramic membrane, said anodizing performed by applying electric current between the metallic tube as an anode and the cathode while absorbing heat produced during the anodization from the outer wall of the metallic tube via the heat sink,
- wherein said anodizing is performed such that a portion of the wall from the inner wall of the metallic tube is anodized, and
- wherein the method further comprises:
- etching, after said anodizing, the inner or outer wall of the metallic tube;
- and, further anodizing a remaining non-anodized portion of the wall of the metallic tube so as to anodize an entire wall of the metallic tube between the outer wall and inner wall of the metallic tube.
7 more elements
A method of producing a nanoporous oxide ceramic membrane comprising:
- providing a metallic tube in a tubular or hollow fiber shape of predetermined dimension;
- placing a cathode inside the metallic tube in cylindrical symmetry to each other;
- placing a heat sink in contact or in close contact with an outer wall of the metallic tube so as to sufficiently absorb heat generated during anodization and to make the anodization process proceed in a steady state;
- filling an electrolyte to soak an inner wall surface of the metallic tube and the cathode with the electrolyte;
- and
- anodizing the metallic tube to produce a nanoporous oxide ceramic membrane, said anodizing performed by applying electric current between the metallic tube as an anode and the cathode while absorbing heat produced during the anodization from the outer wall of the metallic tube via the heat sink,
- wherein said anodizing is performed such that a portion of the wall from the inner wall of the metallic tube is anodized, and
- wherein the method further comprises:
- imprinting performed after said anodizing, on the inner or outer wall of the metallic tube;
- and, further anodizing a remaining non-anodized portion of the wall of the metallic tube so as to anodize an entire wall of the metallic tube between the outer wall and inner wall of the metallic tube.
7 more elements
A method of producing a nanoporous oxide ceramic membrane comprising:
- providing a metallic tube in a tubular or hollow fiber shape of predetermined dimension;
- placing a cathode inside the metallic tube in cylindrical symmetry to each other;
- placing a heat sink in contact or in close contact with an outer wall of the metallic tube so as to sufficiently absorb heat generated during anodization and to make the anodization process proceed in a steady state;
- filling an electrolyte to soak an inner wall surface of the metallic tube and the cathode with the electrolyte;
- and
- anodizing the metallic tube to produce a nanoporous oxide ceramic membrane, said anodizing performed by applying electric current between the metallic tube as an anode and the cathode while absorbing heat produced during the anodization from the outer wall of the metallic tube via the heat sink,
- wherein the membrane comprises thick protruded parts acting as supports for mechanical strengthening and joints for connecting with another neighboring structure, and thin layers with nanopores of 1 to 300 nm in size, and
- wherein the protruded parts are provided by performing a lithography process which comprises:
- coating a portion of the inner or outer walls of the metallic tube with photoresist, followed by exposing to ultraviolet light and etching to provide a shape of the protruded parts before performing said anodizing the metallic tube.
6 more elements
Dependencies are inferred from the claim text.