Patent US4468441A successfully refreshed from Google Patents.
US4468441A
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Separator membranes for redox-type electrochemical cells
Assignee: Rai Research Corp
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Filing: 1982-09-28
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Granted: 1984-08-28
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Expires: 2002-09-28
Abstract
Abstract This disclosure is directed to improved redox type electrochemical cells, preferably those of the iron (+3)/iron (+2) or chromium (+3)/iron (+2) electrolyte variety, incorporating polymeric, ion-exchange separator membranes produced by radiation grafting techniques.
Inventors
- 👤 Vincent F. D'Agostino
- 👤 Joseph Y. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:00
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2231; C08J5/2243; C08J2339/00; C08J2339/04; C08J2339/08; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
75 words
In an improved redox electrochemical cell incorporating two chemically-inert electrodes of opposite polarity, at least one aqueous acidic electrolyte, and a separator membrane between the adjacent electrodes, the improvement comprising an anion exchange separator membrane formed by grafting a polyolefin film to the extent of 5-200% with one or more vinyl substituted monomers via gamma irradiation and subsequently impregnating the grafted film with iron by exposing said film to an aqueous solution of ferric ion.
Claim 2
Dependent Claim
75 words
In an improved redox electrochemical cell incorporating two chemically-inert electrodes of opposite polarity, at least one aqueous acidic electrolyte, and a separator membrane between the adjacent electrodes, the improvement comprising an anion exchange separator membrane formed by grafting a polyolefin film to the extent of 5-200% with one or more vinyl substituted monomers via gamma irradiation and subsequently impregnating the grafted film with iron by exposing said film to an aqueous solution of ferric ion.
Claim 3
Dependent Claim
37 words
The redox cell of claim 21 wherein the grafted film is impregnated with iron by boiling the film in water, bathing the boiled film in an aqueous solution containing ferric ion and washing the film with water.
Claim 4
Dependent Claim
13 words
The redox cell of claim 2 wherein the aqueous solution contains ferric chloride.
Claim 5
Dependent Claim
17 words
The redox cell of claim 3 wherein the aqueous solution is an 0.5-4.0M solution of ferric chloride.
Claim 6
Dependent Claim
47 words
The redox cell of claim 4 wherein the iron-impregnated separator is prepared by boiling the grafted film in water for 5-30 minutes, bathing the boiled film in about 3M aqeuous ferric chloride for about 5-30 minutes, and washing the film with water to remove excess ferric ion.
Claim 7
Dependent Claim
16 words
The redox cell of claims 1 wherein the polyolefin film has been radiation-crosslinked prior to grafting.
Claim 8
Dependent Claim
69 words
In an improved redox electrochemical cell incorporating two chemically-inert electrodes of opposite polarity, at least one aqueous acidic electrolyte, and a separator membrane between the adjacent electrodes, the improvement comprising an anion exchange separator membrane formed by grafting a polyolefin film to the extent of 5-200% with two monomers selected from the group consisting of 2-vinyl-pyridine, 4-vinyl-pyridine, 2-N,N-dimethyl-aminoethyl methacrylate, 2-vinylbenzyl chloride, 4-vinylbenzyl-chloride, acrylic acid, methacrylic acid and 2-N,N-dimethyl-aminoethyl acrylate.
Claim 9
Dependent Claim
69 words
In an improved redox electrochemical cell incorporating two chemically-inert electrodes of opposite polarity, at least one aqueous acidic electrolyte, and a separator membrane between the adjacent electrodes, the improvement comprising an anion exchange separator membrane formed by grafting a polyolefin film to the extent of 5-200% with two monomers selected from the group consisting of 2-vinyl-pyridine, 4-vinyl-pyridine, 2-N,N-dimethyl-aminoethyl methacrylate, 2-vinylbenzyl chloride, 4-vinylbenzyl-chloride, acrylic acid, methacrylic acid and 2-N,N-dimethyl-aminoethyl acrylate.
Claim 10
Dependent Claim
68 words
The redox cell of claim 7 wherein the two monomers are selected from the group consisting of: 2- or 4-vinylpyridine and 2-N,N-dimethylaminoethyl methacrylate; 2- or 4-vinylpyridine and 2- or 4-vinylbenzyl chloride; 2- or 4-vinylpyridine and acrylic acid; 2- or 4-vinylpyridine and methacrylic acid; 2-N,N-dimethylaminoethyl methacrylate and acrylic acid; 2-N,N-dimethylaminoethyl methacrylate and methacrylic acid; 2- or 4-vinylbenzyl chloride and acrylic acid; and 2- or 4-vinylbenzyl chloride and methacrylic acid.
Claim 11
Dependent Claim
31 words
The redox cell of claim 8 wherein the film is low density polyethylene, the monomer pair is 4-vinylpyridine and 2-N,N-dimethylaminoethyl methacrylate, and the percent graft is 10-100% of the membrane weight.
Claim 12
Dependent Claim
16 words
The redox cell of claim 7 wherein the polyolefin film has been radiation-crosslinked prior to grafting.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |