Titanium oxidation tests

In order to understand the general behavior of the tested materials, scoping tests were conducted in 25 mg/L gold(III)-chloride solutions at 25°C and 80°C with different initial pH values, namely 1.5, 4 and 8. After the start of the experiment the pH was not further adjusted, i.e., it could change freely. It remained similar to the initial pH in all cases. From these tests it was found that, in the case of the iron-oxide based adsorbents, dissolution of the solid took place at pHaluminum oxides and titanium oxide was observed at this pH. At pH>2 all adsorbents were found to be stable and did not dissolve during the experiment. 

Wear nitrile rubber gloves, laboratory coat, goggles, and a face shield. Cover the spill with a 1 1 1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. Scoop the mixture into a container and transport to the fume hood. Slowly and cautiously, add the mixture to a pail of cold water. Test the pH of the solution and, if acidic, neutralize with 10% sodium hydroxide solution. Decant the solution into the drain. Treat the solid residue (which contains the highly insoluble titanium oxide) as normal refuse.6... 

More recent investigations by Makower et al (1937), cited above, show that the thickness of nitrogen films adsorbed by soils were of the order of 3.3 X 10-5 cm. On the other hand Harkins and Jura (1944a) report film thicknesses for water, nitrogen, and butane on titanium oxide of 15, 36, and 64 A, respectively. The volume of gas adsorbed and the surface measurements made in these tests are the most accurate thus far obtained. 

Poly(acrylamidoxime) has been tested on laboratory scale as well as in test plants in the sea in form of cross-linked, macroporous resin granules called Duolite ES 346 153). We succeeded in loading this resin in natural sea water with more than 3600 ppm of uranium corresponding to the uranium content of uranium ores mined today. As in the case of hydrous titanium oxide, poly(acrylamidoxime) most probably accumulates the cation UO + without carbonate ligands via the displacement reaction ... 

Several technical processes have been suggested for the recovery of uranium from sea water using solid sorbents, in particular hydrous titanium oxide. The processes have partially been tested in preliminary model plants. Generally, fixed and fluidized sorbent bed operations can be distinguished. 

Wang et al. " compared the model predictions to experimental data on the desulfurization of simulated coal gas from a laboratory-scale fixed-bed reactor and from a process development reactor operated on actual coal gas. The solid reactant was formed from cylindrical pellets of zinc and titanium oxides. Data from six experiments using different temperatures, pressures, feed gas flow rates, and feed gas H2S concentrations were available. Product gas concentrations were measured as a function of time, and the axial distribution of sulfur within the reactor was determined at the conclusion of the test. 

Dos Santos et al. (2014) deposited titanium oxide coatings by PEO in a Ca-P-based electrolyte. The crystalline part of the sample consisted predominately of anatase with minor amounts of rutile, whereby Ca2+ and P043- ions were incorporated into the oxide phases. Cross-sectional images of the coating-substrate interface revealed the presence of voids elongated along the interface. Osteoblast cell cultured at the PEO coating verified the cytocompatibility of the anodised surface. The results of the cytotoxicity tests show satisfactory cell viability of the titanium dioxide films produced in this study. 

Of all the materials tested, three compounds, cupric oxide, titanium oxide, and cadmium oxide showed considerable promise as catalysts. Several experiments were made using cupric oxide, but the results were erratic and not reproducible and it was not further investigated. 

Finally, let us cite a number of new publications dealing with the preparation and testing of hydrated oxide gels hydrated aluminum oxides [30, 32] silica gels, unmodified [11, 13, 16, 21, 27] silica gels, modified [1-4, 9, 14, 19] hydrated titanium oxides [8, 15, 28, 33, 34] hydrated chromiiun oxides [5, 10, 18, 23-25] ... 

Williams and others (Shaw et al., 2003,2005) have used CVD methodologies to produce films of WO3 and chromium titanium oxide. This work demonstrated that the desirable high porosity of the gas sensitive film is obtainable via CVD routes. The suitability for the material as a gas sensor was not tested, but the author suggested the properties might be suitable for gas-sensing. 

Results with oxides tested are compatible with results of Liao et al. for titanium dioxide single crystals (16). It is postulated that the enhancement depertds on the physical form of the oxide type of polymorph present bulk. 

The PPQ failures were characterized as gradually changing from cohesive to adhesive. This type of thermal failure also appeared in Phase I exposure and test. Surface failure analysis had shown that an incompatibility between PPQ resin and the titanium oxide layer had occurred. The PPQ resin was pulling clear from the oxide. Conclusions at this point were that the polymer was thermally stable but an unknown factor was creating an incompatibility with the anodized, prepared oxide. 

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