Membranes having selective permeability

Patent 5096586 Issued on March 17, 1992. Estimated Expiration Date:

August 28, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Patent #: 4329157
Issued on: 05/11/1982
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Patent #: 4451424
Issued on: 05/29/1984
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Inventors

Assignee

Regents of the University of California

Application

No. 573950 filed on 08/28/1990

US Classes:

210/500.37, Amine264/41PORE FORMING IN SITU (E.G., FOAMING, ETC.)

Examiners

Primary: Sever, Frank

Attorney, Agent or Firm

Nilsson, Robbins, Dalgarn, Berliner, Carson & Wurst

Foreign Patent References

62-110729 JP. 05/19/1987
1-38125 JP. 02/19/1989
1-63021 JP. 03/19/1989

International Classes

B01D 067/00
B01D 071/60

Abstract

Dopable, fully dense polymer membranes are used to form membranes having selective permeabilities. To improve selectivity, the membranes may be subjected to chemical or electrochemical treatment with electron donors or acceptors to alter the doping level of the polymer membrane, generally in a reversible fashion. This leads to significant changes in gas permeation rates relative to what is observed for the non-doped, fully dense polymers. This change in doping level of the polymer films can be precisely controlled by varying the concentration and nature of chemical dopants used. Desirable changes in permeation rates are achieved by a treatment which comprises a reversal doping of the polymeric material, followed by removal of the dopants (to provide an "undoped" polymer). Further addition of controlled amounts of at least one dopant species to the undoped polymer by a second, "redoping" procedure can still more dramatically change the permeability of large species, leading to particularly large separation factors.

Other References

Salmon et al., "Chemical Modification of Conducting Polypyrrole Films", Mol. Cryst. Liq. Cryst. 83: 265-276 (1982)
Turillon et al., "New Electrochemically Generated Organic Conducting Polymers", J. Electroanal. Chem., 135: 173-178 (1982)
Waltman et al., "Electrochemical Studies of Some Conducting Polythiophene Films", J. Phys. Chem., 87: 1459-1463 (1983)
Tourillon et al., "Morphology of Conducting Organic Polymers: Polythiophene and Poly(3-Methyl Thiophene)", J. Poly. Sci., 22: 33-39 (1984)
Krische et al., "Composites of Conducting Polymers: Polyacetylene-Polypyrrole", Mol. Cryst. Liq. Cryst, 121: 325-329 (1985)
Wu-Song Huang et al., "Polyaniline, a Novel Conducting Polymer", J. Chem. Soc., Faraday Trans. 1, 82: 2385-2400 (1986)
Lu et al., "Morphological Investigation of Polyaniline," Synthetic Metals 30:87-89 (1989)
Wan, "The Influence of Polymerization Method and Temperature on the Absorption Spectra and Morphology of Polyaniline," Synthetic Metals 31:51-59 (1989