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US 7,404,844 B2Granted
Method for making carbon membranes for fluid separation
AssigneeNational University of Singapore
InventorsPei Shi Tin, Tai Shung Neal Chung
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Abstract
There is disclosed a method of making a high performance carbon membranes from polymer membranes. The method comprising the steps of exposing polymer precursor compounds to a polar organic liquid before pyrolysis of the exposed polymer precursor compounds.
Claims45
A method of making a selectively permeable membrane, the method comprising the steps of:
- casting a solution comprising a solvent and polymer precursor compounds to form a dense polymer film;
- evaporating the solvent from said solution of polymer precursor compounds so that the dense polymer film is substantially absent of solvent;
- exposing the dense polymer film substantially absent of solvent to a polar organic liquid;
- and
- pyrolyzing the exposed dense polymer film to form the selectively permeable membrane, wherein said pyrolyzing and said exposing steps are undertaken under selected conditions such that the membrane selectivity is enhanced relative to a membrane that has not been exposed to said polar organic liquid under said selected conditions.
2 more elements
A carbon molecular sieve membrane made by a method comprising the steps of:
- casting a solution comprising a solvent and carbon containing polymer precursor compounds to form a dense polymer film;
- evaporating the solvent from said solution of carbon containing polymer precursor compounds, so that the dense polymer film is substantially absent of solvent;
- exposing the dense polymer film substantially absent of solvent to a polar organic liquid;
- and
- pyrolyzing the exposed dense polymer film to form the carbon molecular sieve membrane capable of separating gases having different molecular sizes, wherein said pyrolyzing and said exposing steps are undertaken under selected conditions such that the membrane selectivity is enhanced relative to a membrane that has not been exposed to said polar organic liquid under said selected conditions.
2 more elements
A method of making a polymeric membrane for use in a carbon molecular sieve, the method comprising the steps of:
- casting a solution of polymer precursor compounds to form a dense polymer film;
- evaporating the solvent from said solution of polymer precursor compounds, so that the dense polymer film is substantially absent of solvent;
- exposing the dense polymer film substantially absent of solvent to a polar organic liquid;
- and
- pyrolyzing the exposed dense polymer film to form the selectively permeable membrane capable of separating gases having different molecular sizes, wherein said pyrolyzing and said exposing steps are undertaken under selected conditions such that the membrane selectivity is enhanced relative to a membrane that has not been exposed to said polar organic liquid under said selected conditions.
2 more elements
A method of making a membrane, the method comprising the steps of:
- exposing polymer precursor compounds to a polar organic liquid;
- and
- pyrolysing the exposed polymer precursor compounds to form the membrane,
- wherein the membrane is comprised of a polyimide represented by the following general structure (I):
- wherein,
- Ar1 is a quadrivalent organic group;
- Ar2 is an aromatic diamine moiety;
- and
- n is an integer greater than 1 and represents the number of repeating monomer units.
6 more elements
Dependencies are inferred from the claim text.