Precipitation technique

The quickest-and most straightforward-strategy for the preparation of inorganic materials is the precipitation technique, although in the case of metal oxides this often results in amorphous materials that require extensive calcination treatment 

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Lead chromates are prepared by precipitation techniques from soluble salts ia aqueous media. The raw material Hst iacludes a number of different lead compounds, eg, Htharge, lead nitrate, basic lead acetate, basic lead carbonate, as well as acids, alkahes, sodium bichromate, and sodium chromate. The typical reaction can be represented by the foUowiag equation ... 

Conventional Refining Process. The conventional refining process is based on complex selective dissolution and precipitation techniques. The exact process at each refinery differs in detail (12—14), but a typical scheme is outlined in Figure 2. 

The quantitative analysis of additives in a polycarbonate homopolymer has been carried out by micro-SEC-capillary GC and by a conventional precipitation technique (14). The validity of the on-line technique was demonstrated and equivalent... 

The co-precipitation technique starts with an aqueous solution of nitrates, carbonates, chlorides, oxychlorides, etc., which is added to a pH-controlled solution of NH4OH, allowing the hydroxides to precipitate immediately. This method requires water-soluble precursors and insoluble hydroxides as a final product. The hydroxides are filtered and rinsed with water when chlorides are employed as starting materials and chlorine is not desired in the final product. After drying the filtrate, it is calcined and sintered. This method is being applied very successfully for oxygen-ion conducting zirconia ceramics [30],... 

An overview is presented of plutonium process chemistry at Rocky Flats and of research in progress to improve plutonium processing operations or to develop new processes. Both pyrochemical and aqueous methods are used to process plutonium metal scrap, oxide, and other residues. The pyrochemical processes currently in production include electrorefining, fluorination, hydriding, molten salt extraction, calcination, and reduction operations. Aqueous processing and waste treatment methods involve nitric acid dissolution, ion exchange, solvent extraction, and precipitation techniques. 

The solubility product (. sp) describes the equilibrium of a salt dissolving in water. In the laboratory and in industry, solubility equilibria are often exploited in the opposite direction. Two solutions are mixed to form a new solution in which the solubility product of one substance is exceeded. This salt precipitates and can be collected by filtration. Example illustrates how precipitation techniques can be used to remove toxic heavy metals from aqueous solutions. 

In situ precipitation technique Reduces the concentration of the scale-forming ingredients [858,859]... 

The waste from such an operation, if treated by conventional precipitation techniques without an examination of the manufacturing process itself, would impose a severe cost on the manufacturing operation and produce large amounts of sludge for disposal. 

Nanocrystalline gamma iron oxide (y-Fe203) recently been studied as a gas sensing material, has been synthesised at 70°C using sonication-assisted precipitation technique [21]. The synthesised material was then used for fabricating the... 

SnO has received much attention as a potential anode material for the lithium-ion-secondary-battery. The conventional techniques require temperatures above 150°C to form phase pure SnO. Whereas, sonication assisted precipitation technique has been used to prepare phase-pure SnO nanoparticles at room temperature by Majumdar et al. [25]. In this study, ultrasonic power has been found to play a key role in the formation of phase pure SnO as with a reduction in the ultrasonic power authors have observed a mixed phase. For the case of high ultrasonic power, authors have proposed that, intense cavitation and hence intense collapse pressure must have prevented the conversion of SnO to Sn02-... 

Figure 2.11 TEM images and nanoparticle size distributions of nanopartides synthesized from a modified Brust arrested precipitation technique (a) under ambient conditions and (b) at an applied C02 pressure of 33.0 bar.

Zinc electrowinning requires high electrolyte purity.186 Cementation with powdered zinc to remove heavy metals such as Cd, Hg, and Pb, and other precipitation techniques are most... 

As presented by this paper, our aim was to describe some preliminary results demonstrating that amorphous manganese-oxide-based materials synthesised by means of precipitation technique from aqueous solutions could serve as effective cathodes in lithium batteries. 

Purify the biotinylated protein or molecule using dialysis or gel filtration. For small molecule biotinylation where these separation methods may not be appropriate, other procedures may have to be developed, such as reverse-phase chromatography or organic precipitation techniques. 

Protein Precipitation Techniques and Instrumentation for High-Throughput Screening... 

In the late 1970s and early 1980s there was a flurry of interest in precipitation techniques as a method of keeping ions in their in vivo locations, and thus avoid the problems mentioned in Subheading 3.1. The idea was simply to add a precipitant to the fixative, which reacted with the ion in question, and hopefully kept it where it was in the tissue. The most popular technique was to use a silver salt to precipitate chloride ions (35). Two problems emerged loss of ions was not totally prevented (36) and quantification was not possible. This led to the almost complete... 

C 1 g catalyst, H20/EtOH = Catalyst was prepared by co-precipitation technique. Work focused on reactor... 

Catalysts were prepared by impregnation and co-precipitation techniques. Among the catalysts tested in the SRE reaction, the Cu0/Zn0/Al203 exhibited better performance... 

Figure 7. Preparation procedure for precipitating technique. Shown also is the schematic illustration of the diffusion stranding mechanism for nanosphere formation that occurs during the precipitation method.

The dyes with long-lived luminescence are particularly attractive since background fluorescence can easily be discarded in time domain measurements. Crosssensitivity to oxygen may be problematic but it can be minimized by utilizing gas-blocking polymers. For example, Kuemer et al. [15] used the precipitation technique to prepare polyacrylonitrile-based beads doped with a ruthenium(II) complex which showed virtually no cross-sensitivity to oxygen. Copolymers of polyacrylonitrile and polyacrylic acid were used to provide the beads with... 

Carefully selected monoclonal antibodies against apo(a) are well suited for most immunoassays (LI, L2, W17). Precipitation techniques such as nephelome-try or turbidimetry require monospecific polyclonal antisera. 

Similar problems occur for the nephelometric and turbidimetric methods, where the sizes of the IgG-Lp(a) complexes depend upon that of apo(a) itself (L2, W4). Furthermore, problems due to interferences from elevated plasma triglyceride are commonly encountered in the precipitation techniques (C3). As Lp(a) can be redistributed among the Lp(a) fraction and the triglyceride-rich lipoproteins, especially in patients after a fatty meal (B11), these methods are not appropriate for monitoring Lp(a) levels and distribution in plasma. 

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