A carbon molecular sieve (CMS) membrane may advantageously be made by pyrolyzing a membrane precursor composition comprised of a carbon forming polymer (e.g., polyimide) blended with a polyvinylidene chloride copolymer (PVDC), the polyvinylidene chloride copolymer being the reaction product of at least 60% to 97% by weight of vinylidene chloride and at least one other comonomer and the carbon forming polymer to polyvinylidene chloride copolymer has a weight ratio of greater than 1 to 99. The membrane precursor composition may be formed by dissolving the carbon forming polymer and PVDC in a solvent to form a dope solution. The dope solution may be shaped, for example, into an asymmetric hollow fiber. The asymmetric hollow fiber may be heated to a temperature to dehydrochorinate the PVDC and then subsequently heated in a non-oxidizing atmosphere to carbonize the polymers of the shaped membrane to form the CMS membrane.

A carbon molecular sieve (CMS) membrane may advantageously be made by pyrolyzing a membrane precursor composition comprised of a carbon forming polymer (e.g., polyimide) blended with a polyvinylidene chloride copolymer (PVDC), the polyvinylidene chloride copolymer being the reaction product of at least 60% to 97% by weight of vinylidene chloride and at least one other comonomer and the carbon forming polymer to polyvinylidene chloride copolymer has a weight ratio of greater than 1 to 99. The membrane precursor composition may be formed by dissolving the carbon forming polymer and PVDC in a solvent to form a dope solution. The dope solution may be shaped, for example, into an asymmetric hollow fiber. The asymmetric hollow fiber may be heated to a temperature to dehydrochorinate the PVDC and then subsequently heated in a non-oxidizing atmosphere to carbonize the polymers of the shaped membrane to form the CMS membrane.

A carbonized PVDC copolymer useful for the separation of an olefin from its corresponding paraffin may be made by heating a polyvinylidene chloride copolymer film or hollow fiber having a thickness of 1 micrometer to 20 micrometers to a pretreatment temperature of 100° C. to 180° C. to form a pretreated polyvinylidene chloride copolymer film and then heating the pretreated polyvinylidene chloride copolymer film to a maximum pyrolysis temperature from 350° C. to 750° C. A process for separating an olefin from its corresponding paraffin in a gas mixture is comprised of flowing the gas mixture through the aforementioned carbonized polyvinylidene chloride (PVDC) copolymer to produce a permeate first stream having an increased concentration of the olefin and a second retentate stream having an increased concentration of its corresponding paraffin.

A carbonized PVDC copolymer useful for the separation of an olefin from its corresponding paraffin may be made by heating a polyvinylidene chloride copolymer film or hollow fiber having a thickness of 1 micrometer to 20 micrometers to a pretreatment temperature of 100° C. to 180° C. to form a pretreated polyvinylidene chloride copolymer film and then heating the pretreated polyvinylidene chloride copolymer film to a maximum pyrolysis temperature from 350° C. to 750° C. A process for separating an olefin from its corresponding paraffin in a gas mixture is comprised of flowing the gas mixture through the aforementioned carbonized polyvinylidene chloride (PVDC) copolymer to produce a permeate first stream having an increased concentration of the olefin and a second retentate stream having an increased concentration of its corresponding paraffin.

A process for separating hydrogen from a gas mixture having hydrogen and a larger gas molecule is comprised of flowing the gas mixture through a carbonized polyvinylidene chloride (PVDC) copolymer membrane having a hydrogen permeance in combination with a hydrogen/methane selectivity, wherein the combination of hydrogen permeance and hydrogen/methane selectivity is (i) at least 30 GPU hydrogen permeance and at least 200 hydrogen/methane selectivity or (ii) at least 10 GPU hydrogen permeance and at least 700 hydrogen/methane selectivity. The carbonized PVDC copolymer may be made by heating and restraining a polyvinylidene chloride copolymer film or hollow fiber having a thickness of 1 micrometer to 250 micrometers to a pretreatment temperature of 100° C. to 180° C. to form a pretreated polyvinylidene chloride copolymer film and then heating and restraining the pretreated polyvinylidene chloride copolymer film to a maximum pyrolysis temperature from 350° C. to 750° C.

A process for separating hydrogen from a gas mixture having hydrogen and a larger gas molecule is comprised of flowing the gas mixture through a carbonized polyvinylidene chloride (PVDC) copolymer membrane having a hydrogen permeance in combination with a hydrogen/methane selectivity, wherein the combination of hydrogen permeance and hydrogen/methane selectivity is (i) at least 30 GPU hydrogen permeance and at least 200 hydrogen/methane selectivity or (ii) at least 10 GPU hydrogen permeance and at least 700 hydrogen/methane selectivity. The carbonized PVDC copolymer may be made by heating and restraining a polyvinylidene chloride copolymer film or hollow fiber having a thickness of 1 micrometer to 250 micrometers to a pretreatment temperature of 100° C. to 180° C. to form a pretreated polyvinylidene chloride copolymer film and then heating and restraining the pretreated polyvinylidene chloride copolymer film to a maximum pyrolysis temperature from 350° C. to 750° C.

The present invention is related to a polymer membrane for the selective extraction of cobalt (II) ions as well as a method for extracting cobalt (II) ions using said polymer membrane.

The present invention is related to a polymer membrane for the selective extraction of cobalt (II) ions as well as a method for extracting cobalt (II) ions using said polymer membrane.

Magnesium ion selective electrode membranes and the preparation thereof. The membranes are rendered highly selective for magnesium ions by the addition of acidic groups to the preferably PVC membrane, either by introducing a lipophilic compound comprising an acidic group covalently linked to a C4-C18 alkyl-substituted phenyl group (e.g. bis-4-octylphenyl phosphoric acid) into the membrane comprising the magnesium selective ionophore (e.g. a neutral ionophore 1,10-phenanthroline derivative) or by covalently linking an acidic (e.g. a carboxylic) group to the ionophore (e.g. a 1,10- phenanthroline derivative).

A supported carbon molecular sieve (CMS) membrane is made by contacting a film of a carbon forming polymer on a polymer textile to form a laminate. The laminate is then heated to a temperature for a time under an atmosphere sufficient to carbonize the film and polymer textile to form the supported CMS membrane. The supported CMS membrane formed is a laminate having a carbon separating layer graphitically bonded to a carbon textile, wherein the carbon separating layer is a continuous film. The supported CMS membranes are particularly useful for separating gases such as olefins from their corresponding paraffins.