Cetyltrimethyl-ammonium bromide

Yan and associates developed a method for the analysis of iron based on its formation of a fluorescent metal-ligand complex with the ligand 5-(4-methylphenylazo)-8-aminoquinoline. In the presence of the surfactant cetyltrimethyl ammonium bromide the analysis is carried out... 

Acid Detergent Fiber. The ground sample is heated for 1 h under reflux in a solution of 2% cetyltrimethyl ammonium bromide [57-09-0] in IN sulfuric acid [7664-93-9]. The acid hydrolyzes and dissolves the nonceUulosic polysaccharides. The insoluble residue, relatively free of hemiceUuloses and containing aU the ceUulose and lignin, is filtered, dried, and corrected for ash to give the ADF value. 

Barr et al. Bromphenol blue 8 Cetyltrimethyl-ammonium bromide 267... 

Lyotropic liquid crystalline nanoparticles have also been described. Concentrated solutions of gold nanorods in water in the presence of a surfactant (cetyltrimethyl-ammonium bromide) display a nematic mesophase stable up to 200 °C [74[. The N mesophase was identified by optical microscopy by their typical nematic droplets texture. 

The surface active agents (surfactants) may be cationic, anionic or non-ionic. Surfactants commonly used are cetyltrimethyl ammonium bromide (CTABr), sodium lauryl sulphate (NaLS) and triton-X, etc. The surfactants help to lower the surface tension at the monomer-water interface and also facilitate emulsification of the monomer in water. Because of their low solubility surfactants get fully dissolved or molecularly dispersed only at low concentrations and at higher concentrations micelles are formed. The highest concentration where in all the molecules are in dispersed state is known as critical micelle concentration (CMC). The CMC values of some surfactants are listed in table below. 

Systems and materials. The reaction was carried out at several compositions in an ionic and in a nonionic system. The ionic system consisted of an emulsifier (49.6 wt % cetyltrimethyl ammonium bromide (CTAB)/50.4% n-butanol), hexadecane, and water. The nonionic emulsifier consisted of 65.7% polyoxyethylene (10) oleyl ether (Brij 96) and 34.4% n-butanol, again with hexadecane and water. In both systems, mlcroemulslon (pE) compositions used were obtained by diluting an initial 90 weight percent (%) emulsifler/10% oil mixture with varying amounts of water. Micro-emulsion samples thus obtained had final compositions of 30 to 80% water. Phase maps describing these systems have been published (10-11). 

Since N will be larger than S+, all anionic surfactants are negatively charged. Similarly, cationic micelles will be positively charged. For instance, the cationic surfactant cetyltrimethyl ammonium bromide (CTAB), we have following equilibrium in micellar solutions ... 

Contrary to hydrotropes, micelle-forming surfactants spontaneously self-aggregate cooperatively above the critical micelle concentration (cmc) even in the absence of solubilizate. Typical examples of micelle-forming surfactants include sodium dode-cylsulfate (SDS), dodecyltrimethylammonium bromide (DTAB), cetyltrimethyl-ammonium bromide (CTAB), and heptaoxyethylene dodecyl ether (C12E7) (Scheme 2). 

Cetyltrimethyl ammonium bromide (CTAB) dodecyltrimethyl ammonium bromide (DTAB) tetradecyltrimethyl ammonium bromide (TTAB) trioctyl-methyl ammonium chloride (TOMAC) N-benzyl-N-dodecyl-hf-bis(2-hy-droxy ethyl) ammonium chloride (BDBAC) cetyl pyridinimn chloride (CPC) quaternary ammonium salt with carbon atoms of R ranging from 8-10 (CHj Rj N+ CL) (Aliquat 336)... 

The raw materials used were as follows aerosil-200 silica, NaOH, cetyltrimethyl ammonium bromide (CTMABr), NaAlC>2, HF, HC1 and deionised water. 

Hydrotalcite is often too fine grained to produce treatment columns with suitable permeability. As an alternative, the sorbent may be mixed with contaminated water in a tank (Lazaridis et al, 2002). The spent sorbent is then separated from the treated water by flocculation, flotation, or other separation methods (see Section 7.2.4). Lazaridis et al. (2002) investigated the use of surfactants with dispersed-air flotation to separate spent hydrotalcites from treated water. At ionic strengths of 0.1 M using KNO3, effective flotation and separation could be obtained by using a mixture of dodecylpyridinium chloride, sodium dodecylhydrogen sulfate, and a cetyltrimethyl ammonium bromide frother (Lazaridis et al., 2002,322,323). 

Dialysis fluids (continued) Add Ferron and cetyltrimethyl-ammonium bromide solution to sample and measure phosphorescence at 586 nm Phosphor- imetry 5.4 g/L No data De La Campa et al. 1988... 

Name Cetyltrimethyl ammonium bromide adsorbed on silica Structure ... 

Quaternary ammonium compounds. These compounds are cationic surfactants if they contain a hydrocarbon chain of sufficient length. Example cetyltrimethyl-ammonium bromide, CH3(CFl2)isN+(CH3)3Br. See also Cationic Surfactant. 

The method is based on the partitions of the anions to a cationic micelle phase and shows different selectivity from ion exchange chromatography In a kinetic method [13] for the determination of thiocyanate, sulphite and sulphide the anions are reacted with 5,5 dithiobis (2-nitrobenzoic acid) in aqueous cetyltrimethyl/ammonium bromide micelles. 

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