| 1. |
- Dunuwila, Dilum D., et al.
(author)
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Application of controlled hydrolysis of titanium(IV) isopropoxide to produce sol-gel-derived thin films
- 1994
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In: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 6:9, s. 1556-1562
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Journal article (peer-reviewed)abstract
- A variety of porous optically transparent titanium carboxylate films that can be supported on silicate glass substrates have been developed. These films were made by spin casting polymeric solutions of titanium carboxylates processed using sol-gel techniques. The stability and the quality of these films have been qualitatively correlated to the extent of control of hydrolysis exerted by carboxylate modification of the precursor titanium(IV) isopropoxide. A series of carboxylic acids ranging from acetic acid to myristic acid has been used, and their effects on film quality and stability are presented.
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| 2. |
- Dunuwila, Dilum D., et al.
(author)
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An investigation of the applicability of attenuated total reflection infrared spectroscopy for measurement of solubility and supersaturation of aqueous citric acid solutions
- 1994
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In: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 137:3-4, s. 561-568
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Journal article (peer-reviewed)abstract
- Currently applied methods for measurement of solubility and supersaturation based on viscometry, refractometry, interferometry and density require the separation of phases prior to measurement. ATR (attenuated total reflection) infrared spectroscopy provides a unique configuration in which the infrared spectrum of a liquid phase can be obtained in a slurry without phase separation. The applicability of the technique was investigated using a micro Circle® open boat cell equipped with a ZnSe (zinc selenide) ATR rod. Experiments conducted with aqueous citric acid proved that ATR infrared spectroscopy can be successfully employed to determine solubility and supersaturation.
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| 3. |
- Dunuwila, Dilum D., et al.
(author)
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Sol-gel derived titanium carboxylate thin films for optical detection of analytes
- 1994
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In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 66:17, s. 2739-2744
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Journal article (peer-reviewed)abstract
- The feasibility of using a sol-gel derived titanium carboxylate thin film, which can be supported on glass, for the fabrication of optical test strips was investigated using a model probe/ analyte combination. The porous films, being optically transparent and baring the capability to host probe molecules, provided an excellent system to investigate the possibility of making optical test strips. A colorimetric reagent, an iron(III) porpohyrin, was chosen as the probe molecule to detect free cyanide ion concentrations in aqueous solutions. Entrapment of the porphyrin in the film was accomplished by direct dissolution of the porphyrin in the sol-gel solutions. Chemically induced structural modifications of the polymer were carried out to stabilize the encapsulated metalloporphyrin within the sol-gel derived matrix. The syntheses of this model analyte detection system and its response are presented. An optical parameter reflective of the chemical changes that occur in the system was selected as the measurement tool; its response asymptotically increased over the cyanide ion concentration range of 40-25 000 ppm.
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