Titanium mixed metal oxides

Canister anodes consist of a spirally wound galvanised steel outer casing containing a carbonaceous based extender which surrounds the primary anode element which may be graphite, silicon iron, magnetite, platinised titanium, mixed metal oxide-coated titanium or platinised niobium, etc. 

Titanium IV) oxide, T1O2. See titanium dioxide. Dissolves in concentrated alkali hydroxides to give titanates. Mixed metal oxides, many of commercial importance, are formed by TiOj. CaTiOj is perovskite. BaTiOa, per-ovskite related structure, is piezoelectric and is used in transducers in ultrasonic apparatus and gramophone pickups and also as a polishing compound. Other mixed oxides have the il-menite structure (e.g. FeTiOj) and the spinel structure (e.g. MgjTiO ). 

About 100,000 t of titanium dioxide aimuaHy are used as formulation components in the production of glass (qv), ceramics, electroceramics, catalysts, and in the production of mixed-metal oxide pigments. 

Catalytic alkylation of aniline with diethyl ether, in the presence of mixed metal oxide catalysts, preferably titanium dioxide in combination with molybdenum oxide and/or ferric oxide, gives 63% V/-alkylation and 12% ring alkylation (14). 

Anode 1 = plastic cable anode anode 2 = mixed metal oxide-titanium. 

Precious metals and oxides platinised titanium, platinised niobium, platinised tantalum, platinised silver, solid platinum metals, mixed metal oxide-coated titanium, titanium oxide-based ceramics. 

The oxide coatings are porous and therefore the limitations on operating voltage for platinised titanium anodes apply as well to the oxide-coated titanium electrodes. It has been reported that breakdown of mixed metal oxide anodes may occur at 50-60 V in low-chloride concentration water but at only 10 V in chloride-rich environments . 

The most recently developed anode for the cathodic protection of steel in concrete is mixed metal oxide coated titanium mesh The anode mesh is made from commercially pure titanium sheet approximately 0-5-2mm thick depending upon the manufacturer, expanded to provide a diamond shaped mesh in the range of 35 x 75 to 100 x 200 mm. The mesh size selected is dictated by the required cathode current density and the mesh manufacturer. The anode mesh is supplied in strips which may be joined on site using spot welded connections to a titanium strip or niobium crimps, whilst electrical connections to the d.c. power source are made at selected locations in a suitably encapsulated or crimped connection. The mesh is then fitted to the concrete using non-metallic fixings. 

Mixed Metal Oxide Coated Titanium As an alternative to platinised titanium, these materials are finding increasing use in seawater and soil based deep well groundbed applications. 

The formation of rutile mixed phases in the system Ti-Ni-Sb-0 is described in detail in [3.92], When nickel ions are to be included in the pigment and antimony trioxide is used to provide the antimony ions, oxygen must be present to ensure that nickel and antimony occupy the titanium sites in the lattice. If oxygen is excluded, only small amounts of nickel and antimony are taken up in solid solution, and no useful products are formed. The presence of oxidizing agents (e.g., nitrates) is necessary for the production of antimony-containing mixed metal oxide pigments. 

The dimensionally stable anodes (DSA ) consist of a titanium base metal covered by a thin conducting layer of metal oxide or mixed metal-oxide oxides. Since their discovery by Beer (1966) in the late 1960s, a lot of work has been done on DSA and on finding and preparing new coating layers for many electrochemical... 

Numerous ceramics are deposited via chemical vapor deposition. Oxide, carbide, nitride, and boride films can all be produced from gas phase precursors. This section gives details on the production-scale reactions for materials that are widely produced. In addition, a survey of the latest research including novel precursors and chemical reactions is provided. The discussion begins with the mature technologies of silicon dioxide, aluminum oxide, and silicon nitride CVD. Then the focus turns to the deposition of thin films having characteristics that are attractive for future applications in microelectronics, micromachinery, and hard coatings for tools and parts. These materials include aluminum nitride, boron nitride, titanium nitride, titanium dioxide, silicon carbide, and mixed-metal oxides such as those of the perovskite structure and those used as high To superconductors. 

The DSA-type anodes are inert , coated anodes made of a valve metal (titanium, niobium, or tantalum) base coated with an electrochemically active coating. The active coating is made either of noble metals or of mixed metal oxides. Noble metals in active coatings are usually platinum or platinum alloys. Mixed metal-oxide coatings contain active oxides and inert oxides the active components are usually ruthenium dioxide (R.UO2) and iridium dioxide (IrC>2) and the inert components are mostly titanium dioxide (TiC>2) and other oxides such as tantalum... 

A considerable number of materials called titanates are known, some of which are of technical importance. Nearly all of them have one of the three major mixed metal oxide structures (page 54), and indeed the names of two of the structures are those of the titanium compounds that were the first found to possess them, namely, FeTi03, Hmenite, and CaTi03, perovskite. Other titanites with the ilmenite structure are MgTiOa, MnTi03, CoTi03... 

It has been reported that single or mixed metal oxide nanoparticles, such as zinc oxide, copper oxide, aluminum oxide, or titanium oxide, incorporated into a filtration medium containing a binder matrix, can destroy bacteria (57). The metal oxide nanocrystals are included in amounts ranging from approximately 0.1 % up to about 10% by weight, based on the entire filtration medium. In a series of studies, it has been shown... 

Design of cathodic protection for marine structures in both fresh and salt water require special techniques. Galvanic systems usually employ zinc or aluminum alloy anodes. Impressed current systems frequently use high silicon, chromium bearing iron, platinized niobium, or mixed-metal oxide/titanium anodes. The structure being protected affects the design. Stationary facihties such as bulkheads and support piles require different techniques from ship hulls [55]. 

If mixed-metal alkoxide precursors can be prepared and their reactivity can be controlled, ordered macroporous mixed metal oxides can be produced by a sol-gel method using a colloidal crystal template. Alkoxides of Ti and Zr with other metals are easily prepared by mixing titanium alkoxide and zirconium alkoxide with alkoxides of other metals or metal salts, and the formed mixed metal alkoxides can infiltrate the voids of templates. Therefore, production of mixed metal oxides with Ti and Zr is straightforward. 

Mixed metal oxides with Ti or Zr are produced by using alkoxides of mixed metals. Alkoxides of mixed metals with Ti or Zr are produced by mixing titanium alkoxide or zirconium alkoxide with other metal salts or metal alkoxide, and various ordered macroporous BaTi03, CsAlTi04,[ ""l Li4Ti50i2, "> La4Sr8TiiiMno.5Gao.5038-5, >... 

Keywords Hydrogen Iron oxide Mixed metal oxides Titanium dioxide Visible-light activation... 

One of the most successful commercial anodes is the expanded titanium mesh with an activated precious or mixed metal oxide coating. This also comes in the form of an expanded titanium mesh, strips and other configurations. It is fixed onto the surface, usually with plastic fixings and a cementitious overlay applied. 

This anode consists of an expanded titanium mesh with a catalytic mixed metal oxide coating. The anode is fixed to the concrete surface and then overlaid with concrete. This is usually dry spray shotcrete on vertical and soffit surfaces or cast on top surfaces and decks. It is also available in a number of mesh sizes and as a ribbon (described separately). 

Figure 7. II (a) A mixed metal oxide coated titanium mesh anode being overlaid on a bridge in Baltimore MD. Courtesy Jack Bennett, (b) Extreme example of an overlay failure on a titanium mesh anode. Oregon Inlet N. Carolina USA.The whole bridge was swept away in a storm a few years after the author took this photograph. 

As stated in the anode descriptions earlier, there are also two NACE test methods for cathodic protection anodes. These are TM 0294 on embeddable anodes (mixed metal oxide coated titanium, mesh, ribbon, tnbes, rods and conductive ceramic tubes) and TMO1105-2005 on organic-based condnc-tive coating anodes. In addition there is a specification for applying thermal sprayed zinc anodes to concrete American Welding Society (2002). 

Preparation of Various Mixed Metal Oxides. In order to deposit the mixed metal oxide, Pb(Zro.5Tio.5)03 a 2 1 1 stoichiometric solution of the lead, zirconium and titanium precursors was prepared. An amorphous film of these precursors was prepared by spin coating on silicon. 

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