Cadmium sulfoselenide

The cadmium chalcogenide semiconductors (qv) have found numerous appHcations ranging from rectifiers to photoconductive detectors in smoke alarms. Many Cd compounds, eg, sulfide, tungstate, selenide, teUuride, and oxide, are used as phosphors in luminescent screens and scintiUation counters. Glass colored with cadmium sulfoselenides is used as a color filter in spectroscopy and has recently attracted attention as a third-order, nonlinear optical switching material (see Nonlinear optical materials). DiaLkylcadmium compounds are polymerization catalysts for production of poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVA), and poly(methyl methacrylate) (PMMA). Mixed with TiCl, they catalyze the polymerization of ethylene and propylene. 

CdSe forms sohd solutions with CdS which are used as pigments ranging ia color from orange to deep maroon and are called cadmium sulfoselenides. Other uses are ia photocells, rectifiers, lumiaous paiats, and as a mby colorant for glass manufacture. CdSe currentiy sells for 1.50/g as phosphor-grade (99.999% purity) material. 

Pigment Systems. Most of the crystals used for ceramic pigments are complex oxides, owing to the great stability of oxides in molten silicate glasses. Table 3 fists these materials. The one significant exception to the use of oxides is the family of cadmium sulfoselenide red pigments. This family is used because the colors obtained caimot be obtained in oxide systems thus it is necessary to sustain the difficulties of a nonoxide system. 

In an attempt to extend the firing range of these colors, the inclusion pigments (11,17) have been developed. In these pigments cadmium sulfoselenides are incorporated within a clear 2h con lattice. The superior stabiHty of 2h con is thus imparted to the pigment. Colors from yellow to orange-red are available. Deep red is not available, and the purity of these colors is limited. 

Cadmium sulfide yellow can be considered for the brightest low temperature apphcations (15). It is a very bright, clean orange yellow. Primrose yellow and light yellow shades are made by precipitating small amounts of ZnS with the CdS. All the limitations of the cadmium sulfoselenide reds discussed above apply to the cadmium sulfide yellow. 

Thin films of ternary cadmium sulfoselenide CdS Sei-x have been electrodeposited from a non-aqueous organic bath by Baranski et al. [67], as well as by Loutfy and Ng [121], who employed similar principles (deposition from ethylene glycol solution... 

Cadmium Sulfoselenide Orange, pigment for plastics, 7 370t... 

Sulfide and sulfoselenide pigments cadmium sulfoselenide cadmium sulfide (Cd, Zn) S ... 

Cadmium red consists of cadmium sulfoselenide [12656-57-4], [58339-34-7], Cd(S,Se), and is formed when sulfur is replaced by selenium in the cadmium sulfide lattice. With increasing selenium content, the color changes to orange, red, and finally dark red. The density of these pigments increases correspondingly from 4.6 to 5.6 g/cm3 and the refractive index from 2.5 to 2.8. The crystals have cubic or spheroidal habits, the prevalent particle size is 0.3-0.4 pm. 

Mercury-cadmium pigments were developed in the early 1950s as a more cost-effective alternative to cadmium sulfoselenides. Mercury replaces part of the cadmium in the cadmium sulfide compound and eliminates the need for selenium. The resulting pigments range from deep orange to a maroon and offer a cleaner, brighter chroma than their cadmium counterparts. Manufacture is the same as for cadmium sulfides, except that mercury salts are added to the cadmium solution that is reacted with the alkali sulfide solution to cause precipitation. 

In the manufacture of orange to deep red cadmium sulfoselenides using the precipitation process, selenium is dissolved in the sodium sulfide solution in an amount consistent with the color required. Particularly brilliant hues are obtained, if the precipitated raw colorant undergoes brief heat treatment in molten salt at ca. 800°C whereby an optimum particle size of ca. 0.2 to 0.4 pm can be obtained. 

Cepria and coworkers used the voltammetry of immobilized microparticles to detect and quantify the cadmium pigments (e.g., cadmium sulfide and cadmium sulfoselenide) used in artists paints, as well as in glasses, plastics, ceramics, and enamels [141]. For this, a simple, fast and reliable technique was developed that proved to be especially applicable for valuable art objects, as it was minimally invasive and required only nanogram quantities of material (see also Section 6.4.1). For quantification purposes, an abrasive stripping scan was used from + 0.3 V to —1.0 V, following a 10 s pre-treatment step at —1.5 V. The Cd oxidation peak was evaluated with respect to an internal AgCl calibration standard. 

Cadmium/Mercury Sulfides. One of the major accomplishments of the past 25 years has been the introduction of a series of red and maroon pigments based on mercury and cadmium sulfides (CdS xHgS), to replace the well-known cadmium sulfoselenides. The work was prompted by the increasing shortage of selenium and its ever increasing price. In their search for replacement for the standard... 

Another 25% of the selenium production in 1996 was used in inorganic pigments (principally as cadmium sulfoselenide used in plastics, paints, enamels, inks, mbber, and ceramics), and 10-15% of selenium is used in a broad spectrum of applications including accelerators and vulcanizing agents in mbber production, in stainless steel, and as selenides of refractory metals for use in lubricants. Some of these products may end up as disposed waste. Medical and pharmaceutical uses such as in topical preparations for treatment of dandmff, for... 

Orange Azos Benzimidalones Pyrazolones Quinacridones Cadmium sulfide Cadmium sulfoselenides Lead chromates Lead molybdate... 

Red Benzimidalones Disazo s Quinacridones Pyrazolones Cadmium sulfoselenides Iron oxide... 

Until a few years ago, the red pigment for coloring containers, toys, household wares, plastic crates, etc. was Cadmium Red. This is Cadmium sulfoselenide red, C9Hi3CdN204SSe (CAS 58339-34-7), also known as Pigment Red 108 (see Chemnet 2015). The cadmium compound is now considered environmentally undesirable, so it is being replaced by the non-toxic Cerium(III) sulphide (Cc2S3 CAS 12014-93-6). This compound gives a rich red color and is stable up to 350 °C (Emsley 2001). 

---