Oxidation and hydrolysis in the system titanium (III)-oxygen-hydrogen has been studied by a variety of techniques in this work. Solids produced by base precipitation were poorly defined. Although they had an analytical formula corresponding to titanium trihydroxide, the absence of a sharp hydroxide stretching frequency in infra-red spectra showed that they were not simple hydroxides. Such solids, when dry, oxidized immediately upon contact with air to give poorly crystallised products. Heating caused crystallisation when alkali metal hydroxide had originally caused precipitation, the product contained both alkali metal hexatitanate and titanium dioxide of anatase structure; if aqueous ammonia had been the precipitating agent the solid consisted of the anatase structure alone. Aging of solids precipitated by alkali metal hydroxide yielded solely hexatitanates. In a similar manner, mixed alkali metal hexatitanates, of any composition, were prepared by aging and oxidizing the solid precipitated by controlled mixtures of aqueous alkali metal hydroxides. When zinc ions were also initially present, they too participated in the crystallisation process, yielding various zinc titanates. Precipitation by solid sodium hydrogen carbonate yielded poorly defined titanium trihydroxide rather than a carbonate. Hydrolysis products oxidized too quickly to be collected. Oxidized products had either the rutile or anatase structure; when a complexing anion was present the rutile structure was favoured, while the anatase structure was obtained when the anion was only weakly complexing. The thermal decomposition and oxidation of titanium (III) oxalate hydrate was also studied. An intermediate, titanyl oxalate, was observed, while the final, fully oxidised, product had the anatase structure at lower temperatures. Titanium (III) chloride hexahydrate and titanium (III) sulphate pentahydrate were also investigated. No stable intermediates were isolated; fully oxidized products had the anatase structure. A discussion of the various factors which influence the formation of the observed structures concluded this work.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:636334 |
| Date | January 1980 |
| Creators | Cunningham, D. J. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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