Cadmium lead sulfide

The reaction finished within 1 h at 26°C.. They used seed crystals of CdS to promote the uniformity of the final product, and analyzed the growth kinetics using Nielsen s chronomal. The isoelectric point in terms of pH was determined to be 3.7 by electrokinetic measurement. They also prepared zinc sulfide (ZnS polycrystalline spheres), whose isoelectric point in pH was 3.0 (2), lead sulfide (PbS monocrystalline cubic galena) (3), cadmium zinc sulfide (CdS/ZnS amorphous and crystalline spheres) (3), and cadmium lead sulfide (CdS/PbS crystalline polyhedra) (3), in a similar manner. 

The ziac concentrate is first roasted ia a fluid-bed roaster to convert the ziac sulfide to the oxide and a small amount of sulfate. Normally, roasting is carried out with an excess of oxygen below 1000°C so that comparatively Htfle cadmium is eliminated from the calciaed material ia this operation (3). Siace the advent of the Imperial Smelting Ziac Furnace, the preliminary roasting processes for ziac and ziac-lead concentrates result ia cadmium recovery as precipitates from solution or as cadmium—lead fume, respectively, as shown ia Figure 1. 

Copper smelting Copper concentrate, siliceous flux Sulfur dioxide, particulate matter containing arsenic, antimony, cadmium, lead, mercury, and zinc Acid plant blowdown slurry/sludge, slag containing iron sulfides, silica... 

Nanoparticles such as those of the heavy metals, like cadmium selenide, cadmium sulfide, lead sulfide, and cadmium telluride are potentially toxic [14,15]. The possible mechanisms by which nanoparticles cause toxicity inside cells are schematically shown in Fig. 2. They need to be coated or capped with low toxicity or nontoxic organic molecules or polymers (e.g., PEG) or with inorganic layers (e.g., ZnS and silica) for most of the biomedical applications. In fact, many biomedical imaging and detection applications of QDs encapsulated by complex molecules do not exhibit noticeable toxic effects [16]. One report shows that the tumor cells labeled with QDs survived in circulation and extravasated into tissues... 

Cadmium occurs naturally as sulfide co-deposited with zinc, copper, and lead sulfides. It is produced as a by-product in above-mentioned metal processing. Similar to lead and mercury, this heavy metal has no known biological functions in living organisms, and accordingly its accumulation in food and water leads to undesirable consequences to biota. Cadmium toxicology is related to dangerous influence to CNS and excretion systems, firstly, on kidney. 

In another industrial process, flue dusts from smelting lead and zinc concentrates are boiled in acidified water. Thallium dissolves and is separated from insoluble residues by filtration. Dissolved thallium in solution then is precipitated with zinc. Thallium is extracted from the precipitate by treatment with dilute sulfuric acid which dissolves the metal. The solution may also contain zinc, cadmium, lead, copper, indium, and other impurities in trace amounts. These metals are precipitated with hydrogen sulfide. The pure thallium sulfate solution then is electrolyzed to yield thallium. 

Cadmium, Zinc, and Lead Sulfides and Their Mixed Sulfides... 

To date, cadmium sulfide, zinc sulfide, lead sulfide, cadmium selenide, and lead selenide semiconductor particulate films have been grown, in situ, under... 

FIG. 1.13 Spherical and cubic model particles with crystalline or amorphous microstructure (a) spherical zinc sulfide particles (transmission electron microscopy, TEM, see Section 1.6a.2a) x-ray diffraction studies show that the microstructure of these particles is crystalline (b) cubic lead sulfide particles (scanning electron microscopy, SEM, see Section 1.6a.2a) (c) amorphous spherical particles of manganese (II) phosphate (TEM) and (d) crystalline cubic cadmium carbonate particles (SEM). (Reprinted with permission of Matijevic 1993.)... 

The three basic types are photoconductive, photovoltaic, and photo-emissive, and all are sensitive to both heat and light. The resistance of a photoconductive cell is lowered when it is illuminated and, over a small range, its response is linear. Cells containing lead sulfide, which is sensitive at wavelengths greater than 700 nm, and cadmium sulfide or selenide, with a sharp response maximum at 710 nm, have been used but may not give a stable response and are largely restricted to specialized applications in other fields. Silicon photodiodes and transistors are sensitive from 340 to 1200 nm with a peak at 900 nm. 

Quantum detectors are usually made of semiconductor materials or mixtures. Some commonly used quantum detectors are made of lead sulfide (PbS), lead selenide (PbSe), indium antimony (InSb), or mercury cadmium telluride (MCT, HgTe-CdTe). The absorption of infrared radiation in quantum detectors excites electrons... 

Many other systems based on different nanoparticles have been introduced, such as copper indium disulfide (CuInS2) [263-265], copper indium diselenide (CuInSe2) [266,267], cadmium telluride (CdTe) [268], lead sulfide (PbS) [269,270], lead selenide (PdSe) [271], and mercury telluride (HgTe) [272]. Some of these systems show enhanced spectral response well into the infrared part of the solar spectrum [271,272]. In most cases the absorption of the nanocrystals was, however, quantitatively small as compared to the conjugated polymers. 

This type of detector is constituted, for the mid-IR region, of a ternary alloy of mercury-cadmium telluride (MCT) or indium antimonide (InSb) deposited upon an inert support and for the near-IR of lead sulfide (PbS) or an other ternary alloy of indium/gallium/arsenic (InGaAs). Sensitivity is improved when these detectors are cooled down to liquid nitrogen temperature of (77 K). 

The alkaline earth group as a whole stands in marked contrast to transition metals and post-transition metals. For example, most of the metals in the periodic table form insoluble precipitates with the sulfide ion (S2), with the result that sulfide ores of transition and post-transition metals are very common in Earths crust. Common examples of metal sulfides include galena (lead sulfide), cinnabar (mercury sulfide), gree-nockite (cadmium sulfide), acanthite (silver sulfide), cobaltite (cobalt arsenic sulfide), sphalerite (ZnS), stibnite (antimony sulfide), several copper sulfides, orpiment and realgar (both forms of arsenic sulfide), and pyrite (iron sulfide). None of the alkaline earths, however, are found as sulfides. 

The same procedure was applied to the synthesis of cadmium selenide and zinc sulfide in LLC surfactant phases using C EO surfactants. A relationship between the covalent nature of bonds in the final product and the success of the templating procedure was established on the basis of silver sulfide, copper sulfide, mercury sulfide and lead sulfide not producing the same results. The interaction of the surfactant headgroups with the precipitated mineral and with its precursor ions are necessary for direct templating. This is also confirmed by the fact that salts that bind precursor ions prevent the formation of an ordered inorganic nanostructure within the LLC phase [51]. 

IODINE CHLORIDE (7790-99-0) Decomposes explosively below 207°F/97°C. Decomposes on contact with water, steam, alcohols. Reacts violently, causes ignition, or explodes on contact with organic matter, finely divided or foil aluminum or other metals, cadmium sulfide, lead sulfide, organic substances, potassium, phosphorus, phosphorus trichloride, rubber, silver sulfide, sodium, sulfur, zinc sulfide. 

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