Persulphate, ammonium

Such reactions can be initiated by free radicals, derived from compounds (initiators) such as benzoyl peroxide, ammonium persulphate or azobis-isobutyronitrile or by ionic mechanisms... 

Pure uninhibited tetrafluoroethylene can polymerise with violence, even at temperatures initially below that of room temperature. There is little published information concerning details of commercial polymerisation. In one patent example a silver-plated reactor was quarter-filled with a solution consisting of 0.2 parts ammonium persulphate, 1.5 parts borax and 100 parts water, and with a pH of 9.2. The reactor was closed and evacuated, and 30 parts of monomer... 

Aluminium nitrate Ammonium persulphate Barium nitrate/peroxide Calcium nitrate/peroxide Cupric nitrate... 

Ammonium perchlorate Ammonium persulphate Ammonium pernitrate Perchloric acid (>73%)... 

Fig. 13.1 Log/log plot of gold-plate porosity against thickness for the conventional hot-cyanide gold-plating bath on copper substrate. The porosity was determined by the amount of copper (p.p.m.) dissolved under standard conditions by an ammonia-ammonium persulphate...

FIGURE 9.10 In vitro cytotoxicity testing of individual components of recombinant resilin curing polymer system. The light gray areas represent green fluorescence, evidence of live cells, (a) Ammonium persulphate... 

Aluminium sulphate Ammonium bifluoride Ammonium bisulphite Ammonium bromide Ammonium persulphate Antimony trichloride Beryllium chloride Cadmium chloride Calcium hypochlorite Copper nitrate Copper sulphate Cupric chloride Cuprous chloride Ferric chloride Ferric nitrate... 

The most common poly(alkenoic acid) used in polyalkenoate, ionomer or polycarboxylate cements is poly(acrylic acid), PAA. In addition, copolymers of acrylic acid with other alkenoic acids - maleic and itaconic and 3-butene 1,2,3-tricarboxylic acid - may be employed (Crisp Wilson, 1974c, 1977 Crisp et al, 1980). These polyacids are prepared by free-radical polymerization in aqueous solution using ammonium persulphate as the initiator and propan-2-ol (isopropyl alcohol) as the chain transfer agent (Smith, 1969). The concentration of poly(alkenoic add) is kept below 25 % to avoid the danger of explosion. After polymerization the solution is concentrated to 40-50 % for use. 

Poly(alkenoic acid)s may be prepared as follows. 200 cm of a solution containing between 0-5 and 2-5 g of ammonium persulphate contained in a flask is heated to a controlled temperature, lying between 80 and 95 °C, while purging with nitrogen to displace dissolved oxygen. Two solutions. Solution (/) and Solution (II) are added, in the ratio 3-4 10, to the flask charge, with continuous stirring, over a period of two hours. These solutions are ... 

The molecular mass of the polyacid obtained lies between 10000 and 55000. Increasing the temperature of polymerization and the concentration of ammonium persulphate serves to decrease the molecular mass of the poly(alkenoic acid). 

In this case, a moderately water-soluble amphiphilic N-vinylcaprolaclam (NVC1) played the role of a fl-unit, and a well-water-compatible N-vinyl-imidazole (NVIAz) served as a P-unil. The polymerization was carried out in a medium of 10% aqueous dimethylsulfoxide (DMSO). The addition of DMSO to the reaction solvent was necessary because of insufficient NVC1 solubility in pure water. It was also shown that in this solvent mixture, the NVCl-homopolymers and NVCl/NVIAz-copolymers retained their LCST-behaviour [26,28]. Hence, the DMSO in the reaction solvent did not significantly suppress the hydrophobic interactions of the NVC1 units. The polymerization was initiated by the redox system (N,N,N, N -tetramethylethylenediamine (TMEDA) + ammonium persulphate (APS)) and was carried out at 65 °C (1st step). This condition was very important, since admittedly the temperature was higher than the phase separation threshold of the reaction bulk when the polymeric products were formed that is, under these thermal conditions, hydrophobically-induced folding as the NVCl-blocks appear was ensured. After completion of the reaction, the... 

The ester group is then hydrolysed, and the hydrolysis normally stops at the MePO(OH)2 stage. More vigorous conditions are required to rupture the Me—P bond. Thus the normal hydrolysis product of D.F.P. and of tabun, namely, phosphoric acid, will give a positive test with ammonium molybdate, whereas the product from sarin, namely, methylphosphonic acid, will not respond to this test. Vigorous reagents such as hot nitric acid and ammonium persulphate will break the C—P link and then a positive test for phosphate is obtained with ammonium molybdate. Sarin can be prepared in a variety of ways. Three... 

Sarin, which is hydrolysed only to methylphosphonic acid, will not give this colour. If, however, the sarin is first volatilized into ammonium persulphate, and then heated, rupture of the C—P bond takes place at an appreciable rate, and a positive reaction is then usually given. 

Dissolved oxygen (which tends to inhibit the reaction) is removed under a vacuum. Four volumes of ammonium persulphate (3.0 g l-1) are added and gently mixed before pouring into the mould. The mixture is covered with a thin-layer of water to exclude air and allowed to polymerize (approximately 30 min). Protective gloves should be worn and the preparation of the gel carried out in a fume cupboard because the monomers are toxic. 

Polymerization of the gel may be achieved either by ultraviolet photoactivation with riboflavin, or, preferably, using ammonium persulphate as a catalyst. It is necessary to include an initiator for the reaction, TEMED (tetramethylethylene diamine) being commonly used. 

With the preformed ammonium persulphate, oxidation of sulphides to both sulphoxides and sulphones has been observed [e.g. 6, 7] whereas, when Oxone is used in conjunction with a quaternary ammonium salt, oxidation can be selectively stopped at the sulphoxide stage [6-8]. It has been recorded that electron-deficient aryl sulphides, e.g. di(4-nitrophenyl)sulphide, are not readily oxidized. 

As an alternative to simple solvolysis, tosylhydrazones have been oxidatively cleaved to the corresponding ketones in high yield (>90%) using tetra-n-butyl-ammonium persulphate [13]. The reaction has been applied with success even with unsaturated ketones. 

Acrylamide 20% / urea 8 M stock solution 8 M urea solution Ammonium persulphate Siliconized glass plates 30 x 40 cm )... 

Mix the required amount of acrylamide/urea stock solution with TBE buffer and complete with millipore water to give a volume of 250 ml. Then add 10% (w/v) of ammonium persulphate as a catalyst. The polymerization reaction is started by adding 100 pil TEMED. 

Wet cells (15g) in saline (80 ml) are mixed with an equal volume of a 10% w/v monomer solution (85% acrylamide/15% NN methylene bis-acrylamide). Initiator is added (1 ml 5% NNN N -tetramethyldiethylamine and 4 ml 5% ammonium persulphate). Gelation occurs within 20 minutes at 5°C. 

The film deposition was carried out at room temperature from an aqueous solution of plumbous acetate, ammonium acetate, and ammonium persulphate, using NH4OH to bring the pH to 6. A trace of AgNOs was added as a catalyst for reaction 7.4 [29]. A film of PbOi ca. 50 nm thick was formed in an hour. Once this initial film was deposited, thicker films could be built up, usually at a somewhat higher pH, in the absence of the AgNOs. The initial film formation appears to be a pure CD reaction. However, electrochemical studies of further film buildup showed that an electroless deposition mechanism, involving two partial electrochemical reactions, was responsible for film formation. 

Pour the gels in a fume hood. The total gel volume depends on the electrophoresis system used. Mix acrylamide solutions with ammonium persulphate (6 pl/ml gel)... 

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