Micellization effect

The reaction involves the nucleophilic attack of a peracid anion on the unionized peracid giving a tetrahedral diperoxy intermediate that then eliminates oxygen giving the parent acids. The observed rate of the reaction depends on the initial concentration of the peracid as expected in a second-order process. The reaction also depends on the stmcture of the peracid (specifically whether the peracid can micellize) (4). MiceUization increases the effective second-order concentration of the peracid because of the proximity of one peracid to another. This effect can be mitigated by the addition of an appropriate surfactant, which when incorporated into the peracid micelle, effectively dilutes the peracid, reducing the rate of decomposition (4,90). 

Micellar effects can play an important part in aqueous organometallic reactions. Surface active diphosphines have been synthesized and sparingly soluble solutes like decene may well benefit through miceller effects. 

Hydroaminomethylation of alkenes occurred to give both n- and /. so aliphatic amines catalyzed by [Rh(cod)Cl]2 and [Ir(cod)Cl]2 with TPPTS in aqueous NH3 with CO/H2 in an autoclave. The ratio of n-and /.soprimary amines ranged from 96 4 to 84 16.178 The catalytic hydroaminomethylation of long-chain alkenes with dimethylamine can be catalyzed by a water-soluble rhodium-phosphine complex, RhCl(CO) (Tppts)2 [TPPTS P(m-C6H4S03Na)3], in an aqueous-organic two-phase system in the presence of the cationic surfactant cetyltrimethy-lammonium bromide (CTAB) (Eq. 3.43). The addition of the cationic surfactant CTAB accelerated the reaction due to the micelle effect.179... 

N-Alkylhydroxamic acid hydrolysis Methyl Violet + OH" Cl C12H25S03Na + H30+, CTABr + OH". An attempt made to separate electronic and hydrophobic effects on the micellar reaction Anionic and cationic micelles. Effect of surfactant structure examined Berndt el at., 1984 Malaviya and Katiyar, 1984... 

Clouding and Aggregation of Triton X-100 Micelles Effect of Additives... 

Nazario LMM, Hatton TA, Crespo JPSG (1996) Nonionic cosurfactants in AOT reversed micelles Effect on percolation, size, and solubilization site. Langmuir... 

Reverse micelles -effect of supercntical fluids [SUPERCRITICAL FLUIDS] (Vol 23)... 

Zana, R. 1999. Microviscosity of aqueous surfactant micelles Effect of various parardeKir fs. Chem. B. 103 9117-9125. 

Adams, M. L. and G S. Kwon. 2003. Relative aggregation state and hemolytic activity of amphotericin B encapsulated by poly(ethylene oxide)-block-pdty(hexyl-r,-aspartamide)-acyl conjugate micelles effects of acyl chain length Control. Rel81 23-32. 

Micelle Effect on the Write-lock-read-unlock-erase Cycle... 

The increase of hydrophobicity in the substrate shows the increase in the binding. The hydrolysis of 3-nitro-4-acyloxy benzoic acid (8) by poly(4(5)-vinyl-imidazole) (II) is much influenced by the acyl chain length in the substrate (24,25, 56, 72). The increase of the acyl chain length makes the binding increase and the deacylation decrease. In the hydrolysis of the substrate having the longer acyl chain, a micelle effect should be considered. The hydrolysis is much influenced by the micelle formation. 

The emulsification method is primarily used for waterborne epoxy adhesive systems and is the focus of this section. The epoxy resin is made water-dispersible by partitioning the epoxy resin within a micelle, effectively separating the resin from the water. This emulsification can be achieved by a suitable surfactant. 

Proteins in homogenized dairy products Symmetrical Separation of whey proteins from fat globules fractionation of whey proteins and casein micelles effect of carrier ionic strength, cross-flow rate, pH, and membrane type on retention and size distribution of micelles [M. A. Jussila, G. Yohannes, and M.-L. Riekkola, J. Microcol. Separ. 9 601-609 (1997)]... 

H. J. D. McManus, Y. S. Kang, and L. Kevan, Electron spin resonance, electron spin echo, and electron nuclear double resonance studies of the photoieduction yield of a series of alkylmethylviologens in sodium dodecyl sulfate and dodecyltrimethylammonium chloride micelles Effect of the alkyl chain length ofthe viologen, J. Phys. Chem. 96, 5622-5628 (1992). 

Methyl Violet -E OH Cl Anionic and cationic micelles. Effect of surfactant structure examined Malaviya and Katiyar, 1984... 

To account for the micelle effect, specific parameters of the respective surfactant micelles have to be known. Numerous papers on the determination of aggregation numbers and rate constants of micelle kinetics of many surfactants have been published (for example Aniansson et al. 1976, Hoffmann et al. 1976, Kahlweit Teubner 1980). Different micelle kinetics mechanisms exist, for example that summarised by Zana (1974). Three of these mechanisms are demonstrated in Fig. 4.12. 

For example, cationic micelles effectively speed reactions involving nucleophilic anions, e.g., OH , but cations such as (5) and (6) are completely ineffective in this regard. Thus the high charge density of ionic micelles allows them to bind hydrophilic counterions, whereas single hydrophobic cations, or small clusters of them, do not have this ability. 

Marin A, Muniruzzaman M, Rapoport N. Acoustic activation of drug delivery from polymeric micelles Effect of pulsed ultrasound. J Control Release 2001 71 239 249. 

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