US5236667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface modification of plastic optical fibers
Assignee: University of Pittsburgh
•
Filing: 1991-06-25
•
Granted: 1993-08-17
•
Expires: 2011-06-25
Abstract
Abstract A method of chemically modifying the poly (methyl methacrylate) (hereinafter "PMMA") clad surface of an optical fiber to introduce amino groups. N-butyl lithium in a suitable organic solvent with ethylene diamine is applied to the clad surface of the optical fiber in a substantially oxygen-free atmosphere, such as nitrogen, at approximately 10 DEG C. to 40 DEG C. for about one to two hours. A pH-sensitive dye with isothiocyanate functionality can be bounded to the modified clad surface resulting in a pH sensor based on fiber optics.
Inventors
- 👤 Jules B. Puschett
- 👤 Krzysztof Matyjaszewski
- 👤 Bhalchandra Karandikar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:24
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/045; G02B1/048
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
41 words
An optical fiber comprising: an optical fiber having a surface composed of poly (methyl methacrylate) which is modified by applying to said surface the reaction product of a reaction effected in a substantially oxygen-free atmosphere of N-butyl lithium with ethylene diamine.
Claim 2
Dependent Claim
41 words
An optical fiber comprising: an optical fiber having a surface composed of poly (methyl methacrylate) which is modified by applying to said surface the reaction product of a reaction effected in a substantially oxygen-free atmosphere of N-butyl lithium with ethylene diamine.
Claim 3
Dependent Claim
66 words
A pH-sensor comprising: an optical fiber having a surface composed of poly (methyl methacrylate) which is modified by applying to said surface the reaction product of a reaction effected in a substantially oxygen-free atmosphere of N-butyl lithium with ethylene diamine and using amino groups introduced by said applying of said reaction product onto said surface of said fiber to bind a pH-sensitive dye with isothiocyanate functionality.
Claim 4
Dependent Claim
66 words
A pH-sensor comprising: an optical fiber having a surface composed of poly (methyl methacrylate) which is modified by applying to said surface the reaction product of a reaction effected in a substantially oxygen-free atmosphere of N-butyl lithium with ethylene diamine and using amino groups introduced by said applying of said reaction product onto said surface of said fiber to bind a pH-sensitive dye with isothiocyanate functionality.
Claim 5
Independent Claim
92 words
A method of testing for pH, the steps comprising: providing an optical fiber having a surface composed of poly(methyl methacrylate), applying to the surface thereof the reaction product of a reaction effected in a substantially oxygen-free atmosphere of N-butyl lithium with ethylene diamine, utilizing amino groups introduced by applying the reaction product onto said surface of said fiber to subsequently modify said surface of said optical fiber by binding a pH-sensitive dye with isothiocyanate functionality, and subsequently employing said optical fiber with said pH sensitive dye bound thereto as a pH sensor.
Claim 6
Independent Claim
92 words
A method of testing for pH, the steps comprising: providing an optical fiber having a surface composed of poly(methyl methacrylate), applying to the surface thereof the reaction product of a reaction effected in a substantially oxygen-free atmosphere of N-butyl lithium with ethylene diamine, utilizing amino groups introduced by applying the reaction product onto said surface of said fiber to subsequently modify said surface of said optical fiber by binding a pH-sensitive dye with isothiocyanate functionality, and subsequently employing said optical fiber with said pH sensitive dye bound thereto as a pH sensor.
References Cited (Backward Citations)
US4050895A
Cited
US4240796A
Cited
US4200110A
Cited
US4560248A
Cited
US4568518A
Cited
US4803049A
Cited
US4886338A
Cited
US4859538A
Cited
US4834496A
Cited
US4883338A
Cited
US4925268A
Cited
US5077078A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-16 | 1997-02-15 | 1997-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-16 | 2001-02-15 | 2001-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-16 | 2005-02-15 | 2005-08-17 | $7700.00 | Window Closed / Lapsed |