Hydrogen sensitive films and sensors produced therefrom
Described are sensors and methods of detecting hydrogen gas. The sensor includes a polymer matrix and a dye molecule in an amount sufficient such that exposure of the polymer matrix to hydrogen gas causes a change in a spectroscopic property of the dye molecule wherein the spectroscopic property includes at least one of color, absorbance, or luminescence. The polymer matrix may further include a catalyst, such as a transition metal, sulfonated Wilkinson's catalyst, colloidal Pt, sulfonated iridium cyclooctadiene triphenylphosphine, sulfonated rhodium cyclooctadiene triphenylphosphine, sulfonated ruthenium triphenylphosphine, or combinations thereof. Embodiments of the sensor may further include a gas permeable, water impermeable membrane, an outer covering, or combinations thereof.
1. A hydrogen sensor comprising:
a polymer matrix and a dye molecule in an amount sufficient such that exposure of the polymer matrix to hydrogen gas causes a change in a spectroscopic property of the dye molecule wherein the spectroscopic property includes at least one of color, absorbance, or luminescence;
wherein the polymer matrix further includes a catalyst in an amount sufficient to catalyze the change in spectroscopic property of the dye molecule upon exposure to hydrogen gas.
2. The sensor of claim 1 wherein the dye molecule is a polyaromatic compound containing a redox-sensitive chromophore or fluorophore.
3. The sensor of claim 1 wherein the dye molecule is selected from the group consisting of methylthioninium chloride (methylene blue), resazurin (C 12 H 6 NNaO 4 ), neutral red, methyl orange, crystal violet, Victoria blue, Evan's blue, bromophenol blue, thymol blue, orange II, or combinations thereof.
4. The sensor of claim 1 wherein the polymer matrix is selected from the group consisting of agarose, Nafion™ copolymer-fluoropolymer, sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene, poly(vinylbenzene trimethylammonium) chloride, poly(dimethyldiallylammonium chloride), poly(styrenesulfonic acid), quaternized poly(4-vinylpyridine), polyvinyl alcohol, or polyacrylic acid.
5. The sensor of claim 1 wherein the polymer matrix is principally composed of one or Nafion™ copolymer-fluoropolymer or agarose.
6. The sensor of claim 1 , wherein the catalyst is a transition metal, sulfonated Wilkinson's catalyst, colloidal Pt, sulfonated iridium cyclooctadiene triphenylphosphine, sulfonated rhodium cyclooctadiene triphenylphosphine, sulfonated ruthenium triphenylphosphine, or combinations thereof.
7. The sensor of claim 1 wherein the catalyst is a nanoparticle, a microparticle, a sub-nanoparticle, or combinations thereof.
8. The sensor of claim 1 wherein the catalyst is a transition metal selected from the group consisting of palladium (Pd), platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir) or combinations thereof.
9. The sensor of claim 1 wherein the catalyst includes at least two transition metals selected from the group consisting of gold (Au), palladium (Pd), platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir) or combinations thereof.
10. The sensor of claim 9 , wherein the catalyst is a bimetallic catalyst comprising gold and palladium.
11. The sensor of claim 1 further comprising a gas-permeable, water-impermeable membrane affixed to the polymer matrix.
12. The sensor of claim 11 , further comprising an adhesive coated on a surface of the gas-permeable membrane opposite that to which the polymer matrix is affixed.
13. The sensor of claim 11 wherein the gas-permeable membrane is colored or reflective to improve visualization of the dye molecule in the polymer matrix.
14. The sensor of claim 11 further comprising a supporting layer to which the polymer matrix and membrane are affixed.
15. The sensor of claim 14 , wherein the surface of the supporting layer opposite that to which the polymer matrix is affixed is coated, in whole or in part, in adhesive.
16. The sensor of claim 1 , further comprising an optically transparent layer covering or coating the exterior, non-sensing surface of the polymer matrix.
17. The sensor of claim 1 wherein the change in spectroscopic property is reversible.
18. A method for detecting hydrogen gas comprising;
coupling a hydrogen gas sensitive matrix comprising a polymer matrix and a dye molecule adjacent to a potential source of hydrogen gas, wherein the hydrogen gas sensitive matrix further includes a catalyst;
observing a change in a spectroscopic property wherein the spectroscopic property includes at least one of color, absorbance, or luminescence indicative of the presence of hydrogen gas from the hydrogen gas source.
19. The method of claim 18 wherein the hydrogen gas sensitive matrix is coupled to the skin of a subject overlying a magnesium alloy implant.