Cadmium thermal properties

CdO is used in connection with the stabilization of poly(vinyl chloride). This is discussed below in more detail. It also finds application in modifying the thermal properties of teflon and some rubbers. CdS is used in some smoke detectors, in lasers and in phosphors. The cadmium(II) halides are important as catalysts and are also used in pyrotechnics. Cadmium borates of the general type (Cd0)x(B203), are also used as phosphors. CdS04 is employed in the Weston cell, which is important as a voltage standard.137... 

Some other results of KDNP investigations were summarized by Fronabarger et al. [49]. The report unfortunately does not specify the crystal form of the material. Nevertheless, the reported properties are as follows impact sensitivity by ball drop method—51 22 mJ, friction sensitivity by BAM 175 g (no-fire level) 200 g (low fire level), thermal properties by DSC at 20 °C min —small endo at 145 °C, decomposition onset 278 °C, solubility in water—moderately soluble at normal temperature. Reactivity with aluminum, stainless steel, brass, and cadmium was not observed. Output measured as an impetus is reported better than LS in a closed bomb test. 

Allara, D. L., Swalen, J. D. (1982), An infiared reflection spectroscopy study of oriented cadmium arachidate monolayer films on evaporated silver. J. Phys. Chem., 86,2700-4. Asif,A., Shi, W., Shen, X.,Nie, K. (2005), Physical and thermal properties of UV curable waterborne polyurethane dispersions incorporating hyperbranched aliphatic polyester of varying generation number, Po/ywier, 46,11066-78. 

Let us add here that the fabrication of polycrystalline semiconductive films with enhanced photoresponse and increased resistance to electrochemical corrosion has been attempted by introducing semiconductor particles of colloidal dimensions to bulk deposited films, following the well-developed practice of producing composite metal and alloy deposits with improved thermal, mechanical, or anti-corrosion properties. Eor instance, it has been reported that colloidal cadmium sulfide [105] or mercuric sulfide [106] inclusions significanfly improve photoactivity and corrosion resistance of electrodeposited cadmium selenide. 

Many organocadmium compounds are known but few have been of commercial importance. Wanklyn first isolated diethyl cadmium in 1856. The properties of this and other dialkylcadmiums are listed in Table 4. In general, these materials are prepared by reaction of an anhydrous cadmium halide with a Grignard or alkyUithium reagent followed by distillation of the volatile material in an inert atmosphere or in vacuo. Only the liquid dimethyl compound is reasonably stable and then only when stored in a sealed tube. Dimethylcadmium is mildly pyrophoric in air and produces dense clouds of white, then brown, cadmium oxide smoke, which is highly toxic if breathed (45). When dropped into water, the liquid sinks in large droplets that decompose with a series of small explosive jerks and pops. For this reason, and particularly because of the low thermal stability, most dialkylcadmium materials are prepared and used in situ without separation, eg, in the conversion of acid chlorides to speciality ketones (qv) ... 

In general, the cadmium halides show in their crystal structure the relation between polarizing effect and si/e of anion. The tluoride has tile smallest and least polarizable anion of Ihe lour and forms a cubic structure, while the mure polarizable heavy halides have hexagonal layer structures, increasingly covalent and al increasing distances apart in inxler down tire periodic table, in solution the halides exhibit anomalous thermal and transport properties, due primarily to the presence of complex ions, such as CDlr and CdBr r. especially in concentrated solutions or those containing excess halide ions. 

Certain acid dyes [67] stabilize silver oxalate by forming surface compounds, while other dyestufis accelerate the decomposition because their redox properties enhance the ease of electron transfer from the oxalate ion to the silver. The influences of incorporated cadmium, copper and other ions on the rate of thermal decomposition, and on the concentration and mobility of interstitial silver ions, have been reviewed [46,68]. 

A lead sultidc photoconducior is the most widely used transducer for the near-lR region of the spectrum rrv)m lO.tMKi to 333 cm (I to 3 pm). It can be operated at room temperature. For mid- and far- R radiation, M(T pholoconductor transducers are used. They must be cooled with liquid nitrogen (77 K) to minimize thermal noise. The long-wavelength cutoff, and many of the other properties of these transducers, depend on the ratio of the mercury tclluride to cadmium lelluride. which can be varied continuously. 

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