Titanium chemical properties

Hafnium [7440-58-6] Hf, is in Group 4 (IVB) of the Periodic Table as are the lighter elements zirconium and titanium. Hafnium is a heavy gray-white metallic element never found free in nature. It is always found associated with the more plentiful zirconium. The two elements are almost identical in chemical behavior. This close similarity in chemical properties is related to the configuration of the valence electrons, and for zirconium and... 

Zirconium i dride. Zirconium hydride [7704-99-6] ZrH2, is a britde, metaUic-gray soHd that is stable in air and water, and has a density of 5.6 g/cm. The chemical properties of ZrH2 closely resemble those of titanium hydride. Thermal decomposition in vacuum (1 mPa (7.5 x 10 //mHg)) begins at 300°C and is nearly complete at 500—700°C. It is prepared in the same manner as T1H2. 

Physical and Chemical Properties. Titanium dioxide [13463-67-7] occurs in nature in three crystalline forms anatase [1317-70-0] brookite [12188-41 -9] and mtile [1317-80-2]. These crystals are essentially pure titanium dioxide but contain small amounts of impurities, such as iron, chromium, or vanadium, which darken them. Rutile is the thermodynamically stable form at all temperatures and is one of the two most important ores of titanium. 

Color Concentrates. Color concentrates have become the method of choice to incorporate colorants into resins. Color concentrates have high ratios of colorant to a compatible vehicle. The colorant may be added at 70% colorant to 30% vehicle in a titanium dioxide mixture whereas the ratio may be 15% colorant to 85% vehicle in a carbon black mixture. The amount of colorant that can be added is dependent on the surface area and the oil absorption of the colorant and the wetting abiHty of the vehicle. The normal goal is to get as much colorant in the concentrate as possible to obtain the greatest money value for the product. Furthermore, less added vehicle minimizes the effect on the physical or chemical properties of the resin system. 

This example of aluminium illustrates the importance of the protective him, and hlms that are hard, dense and adherent will provide better protection than those that are loosely adherent or that are brittle and therefore crack and spall when the metal is subjected to stress. The ability of the metal to reform a protective him is highly important and metals like titanium and tantalum that are readily passivated are more resistant to erosion-corrosion than copper, brass, lead and some of the stainless steels. There is some evidence that the hardness of a metal is a signihcant factor in resistance to erosion-corrosion, but since alloying to increase hardness will also affect the chemical properties of the alloy it is difficult to separate these two factors. Thus althou copper is highly susceptible to impingement attack its resistance increases with increase in zinc content, with a corresponding increase in hardness. However, the increase in resistance to attack is due to the formation of a more protective him rather than to an increase in hardness. 

Some physical and chemical properties of the alkaline earth metals are shown in Table II. It can be seen that beryllium is significantly different from the elements below it in the periodic table in most respects. The fact that the density of beryllium is greater than that of magnesium is perhaps surprising, but can be understood by noting that magnesium is both a more massive and a larger atom. The density of beryllium is to be compared to that of iron (7.9 g cm-3), titanium (4.5 g cm-3), and aluminum (2.7 g cm-3). 

Phosphorus compounds, 19 19-73 bond properties of, 19 26 chemical properties of, 19 20-31 chiral-centered, 19 25-26 economic aspects of, 19 67-69 as flame retardants, 19 51 inorganic, 11 487-488 oxidation states, coordination numbers, and geometries of, 19 20-26 as oxyacid derivatives, 19 20 reactive organic, 11 496 497 titanium in, 25 56-57 triply connected, 19 25 U.S. prices of, 19 68t U.S. production of, 19 67t... 

Metal ion modified polyimide films have been prepared to obtain materials having mechanical, electrical, optical, adhesive, and surface chemical properties different from nonmodified polyimide films. For example, the tensile modulus of metal ion modified polyimide films was increased (both at room temperature and 200 0 whereas elongation was reduced compared with the nonmodif ied polyimide (i). Although certain polyimides are )cnown to be excellent adhesives 2) lap shear strength (between titanium adherends) at elevated temperature (275 0 was increased by incorporation of tris(acetylacetonato)aluminum(III) (2). Highly conductive, reflective polyimide films containing a palladium metal surface were prepared and characterized ( ). The thermal stability of these films was reduced about 200 C, but they were useful as novel metal-filled electrodes ( ). 

The physical and chemical properties of the tetrahydroborates show more contrasts than the salts of nearly any other anion. The alkali metal salts are the most stable. In dry air, NaBH4 is stable at 300°C and in vacuo to 400°C with only partial decomposition. In contrast, several tetrahydroborates, including the titanium, thallium, gallium, copper, and silver salts, are unstable at or slightly above ambient temperatures. The chemical and physical properties of the tetrahydroborates are closely related to molecular structure. Sodium tetrahydroborate, which is typical of the alkali metal tetrahydroborates except for the lithium salt, has a face-centered cubic (fee) crystal lattice which is essentially ionic and contains the tetrahedral [BHJ- anion. The tetrahydroborates of the polyvalent metals are in many cases the most volatile derivatives of these metals known. Aluminum tris(tetrahydroborate)... 

Chemical Properties. Titanium dioxide is amphoteric with very weak acidic and basic character. Accordingly, alkali-metal titanates and free titanic acids are unstable in water, forming amorphous titanium oxide hydroxides on hydrolysis. 

Jhe distribution of beryllium, boron, titanium, vanadium, chromium, cobalt, nickel, copper, zinc, gallium, germanium, tin, molybdenum, yttrium, and lanthanum in the principal coal-producing beds of the Interior Province has been studied by the U. S. Geological Survey. Data, methods of sampling, and analyses are discussed by Zubovic and others (II, 12). This chapter discusses the occurrence of 13 of these elements with respect to geological and geochemical environments of coal deposition and chemical properties of the elements. Zinc and tin are not included in this study because they were detected in only a few samples. 

A material is a biomaterial when it meets certain requirements it has to have the right physical and chemical properties and, in addition, be biocompatible, which means that it must not be rejected by the body. The material may not release any substances which might activate the host s immune system. As indicated earlier, the first biomaterials were metals and these still play an important part. Of all metals and alloys, titanium appears to be accepted best by tissues. Actually this is rather peculiar, as titanium is relatively rare in vegetable and animal tissue but relatively abundant in the earth s crust (0.2% of the mass of the earth s crust is titanium only six other metals are even more abundant). For some time now, titanium has been used in dental surgery and in attaching and replacing bones and joints. 

Common chemical properties The alkali metals are so chemically reactive that they are never found free in nature. Sodium and potassium react explosively with water to produce hydrogen gas. The alkaline earth metals are not quite as reactive as the alkali metals. The alkali metals react with water but not explosively. The transition metals are generally the least reactive of all the metals. However, when they combine with other elements, they form a large variety of colored compounds. Chromium oxide is green, titanium oxide and zinc oxide are white, manganese oxide is purple, and iron oxide is ochre. 

Crystal field theory is one of several chemical bonding models and one that is applicable solely to the transition metal and lanthanide elements. The theory, which utilizes thermodynamic data obtained from absorption bands in the visible and near-infrared regions of the electromagnetic spectrum, has met with widespread applications and successful interpretations of diverse physical and chemical properties of elements of the first transition series. These elements comprise scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel and copper. The position of the first transition series in the periodic table is shown in fig. 1.1. Transition elements constitute almost forty weight per cent, or eighteen atom per cent, of the Earth (Appendix 1) and occur in most minerals in the Crust, Mantle and Core. As a result, there are many aspects of transition metal geochemistry that are amenable to interpretation by crystal field theory. 

The GD plasma environment is an interesting vessel to study gas-phase chemical properties. The gettering qualities of carbon, silver, tantalum, titanium, and tungsten were compared by Mei and Harrison [40] on the basis of the atomic ion fraction of all of the observed lanthanum species R = La+/(La+ + LaO+) X... 

In this chapter we will review the synthesis, structural aspects, and basic chemical properties of formally divalent and trivalent titanium and zirconium metallocene complexes. We have restricted our coverage to the low-valent bis(rj-cyclopentadienyl) and related metallocenes metal halide complexes and organometallic mixed metal systems will not be discussed here. We have not attempted to present an exhaustive coverage of the field. Rather, our aim has been to describe critically and to evaluate the often confusing chemistry that has been reported for the reactive low-valent titanium and zirconium metallocenes. More general reviews (7) and a book (2) on the organometallic chemistry of titanium, zirconium, and hafnium have been published. 

This chapter attempts to summarize the literature on this class of complexes from the publication of COMC (1995) to 2004 or early 2005. Synthesis, structure, and chemical properties of organometallic titanium(iv) compounds, which contain different types of Ti-C bonds supported by additional ligands, will be covered. We attempt to highlight the major developments from 1993 and tentatively to reveal new trends in this field over the next few years. 

Reactions of Cp TiCl2Me or Cp TiMe3 with dendrimers of first, second, or fourth generations afford the corresponding organometallic titanium-decorated dendrimers (Scheme 390). The dendritic framework remains chemically inert and spectroscopically unchanged by the modifications in the periphery, while the organometallic unit shows spectroscopic and chemical properties similar to the mononuclear counterparts.927... 

From the physico-chemical properties of the melts of the system KF-KCl-KBF4-K2T1F6, it follows that the most characteristic feature of these melts is the formation of the thermodynamically less stable ionic species TiFy and TiFeCl " with lowered symmetry of the coordination sphere in the melt. The presence of these anions in the melt facilitates most probably the electro-reduction of titanium and thus the formation of titanium diboride on the cathode. 

MacDonald, D.E. et al., Physico-chemical properties of human plasma fibronectin binding to well characterized titanium dioxide. Colloids Surf. B, 11, 131, 1998. 

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