摘要:

In the past twenty five years, microemulsions have been the focus of extensive research worldwide due to their importance in a variety of technological applications. These applications include enhanced oil recovery, combustion, cosmetics, pharmaceuticals, agriculture, metal cutting, lubrication, food, enzymatic catalysis, organic and bio-organic reactions, chemical synthesis of nanoparticles etc. The basic purpose of this review is intended to provide the most important features of microemulsions and their applications. Emphasis is placed on recent works, however, the reference list is by no means complete. In order to limit the size of the review, a more or less arbitary selection has been made with respect to examples chosen from literature.

ISSN:0193-2691    

DOI:10.1080/01932699708943740

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The alkaline hydrolysis of dimethylformamide has been studied at 40'C in micellar solutions of single surfactant (CTAB. SDS. Brij 35) with the analog thermoanalytical curve method of thermokinetics. A kinetic equation of micellar catalysis under the condition of highter reactant concentration than micellar concentration ([S]>[M]) has been derived from the pseudophase model of micellar catalysis and some relative assumptions, The kinetic parameters. km, k2mand the association constant of reactant with micelle K1, have been calculated in this way. the results indicate that these surfactant micelles exhibit catalytic effect on the reaction. This is attributed to the micropolarity and local concentration effect of micelles.

ISSN:0193-2691    

DOI:10.1080/01932699708943741

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The microenviromental properties of sodium perfluorooctanoate(SPFO) and cetyltrimethylammonium bromide(CTAB) mixed micellar solutions were studied by using ESR, NMR and surface tension measurement al the air/water interface. The mixed anionic fluorocarbon and cationic hydrocarbon surfactants in this special case have higher surface activity since it is not universal for any type of syatem.1H NMR results show that there is strong interaction between cationic surfactant and anionic surfactant either as hydrocarbon surfactant or fluorocarbon surfactant mixture due to strong electric static interaction of opposite charge head group, synergistic to form the mixed micelles, and indicating diat SPFO molecules penetrate into the interior of CTAB micelles. ESR using 5-doxyi stearic acid label technique reveals the increase of microviscosity of the mixed micellar interface.

ISSN:0193-2691    

DOI:10.1080/01932699708943742

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Acrylamide is conveniendy polymerized in aqueous solution lo a water soluble polymer. The measurements of kinetic parameters of polymerization of acrylamide, in aqueous and micellar solution, have been earned out by conduction calorimeter. The polymerization is initiated by sodium sulfite and sulfite-persulfate redox system. The effect of initiator and monomer concentration as well as temperature and surfactants on polymerization rale constant has been investigated. The analog thermogram method has been employed to calculate the rate constants. The activation energy is calculated from Arrhenius relationship and molecular weights are determined by viscometry. Rate equations have been derived and reaction mechanism hove been suggested. The rate of reaction is found to increase with temperature and monomer concentration.

ISSN:0193-2691    

DOI:10.1080/01932699708943743

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The phase diagram of a sunscreen, ethylhexyl p-methoxycinnamate (EPMC), nonylphenyl ethoxylates-8 (NPE-8), and water was determined. The EPMC was solubilized in the lamellar liquid crystal of NPE-8 and water to 15% by weight. Low angle x-ray diffraction was used to determine the location of the EPMC molecules in the liquid crystal. They were found to penetrate between the hydrocarbon chains of the surfactant.

ISSN:0193-2691    

DOI:10.1080/01932699708943744

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Inorganic small particles were obtained by the chemical reaction of CUSO4 and urea in aqueous solution, anionic AOT-water and cationic CTAB-hexanol-water lamellar liquid crystals. X-ray diffraction and IR spectrum showed that different product were obtained from different systems. The product were CU4(OH)6SO4for aqueous solution, an inorganic mixture for CTAB system and microcrystal containing organic groups for AOT system. The the products formed in liquid crystals are particles or sheet in shape and have narrow size distribution. Particle size increased with reaction time, but the rate of growth of the particle in aqueous solution is faster than in liquid crystals. Comparing the average diameter of the particles formed in three systems, the size was reduced in the following order: D(water)>D(CTAB-hexanol-water)>D(AOT-water).

ISSN:0193-2691    

DOI:10.1080/01932699708943745

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The micropolarity of normal micellar interior of ionic surfactants, sodium dodecyl sulphate (SDS) and cetyltrimethylammonium bromide (CTAB), above critical micelle concentration, associated with the addition of pentanol ( or pentanol/hydrocarbon 50:50 wt/wt) were determined by means of fluorescent probe, pyrene. The results showed a decrease in the ratio of the intensity pyrene emission at higher pentanol content, suggesting a lower micropolarity of the micellar interior at increased amount of pentanol. The micropolarity of the micellar interior with CTAB was, however, found to be higher than the corresponding one with SDS. A transition in the micellar shape was also observed in both of the ionic surfactant systems.

ISSN:0193-2691    

DOI:10.1080/01932699708943746

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The effects of protein addition (lysozyme and bovine serum albumin) on surface tension reduction and cloud point of a surfactant (Pentaethyleneglycol Mono n-Dodecyl Ether (C12E5)) were studied. The minimum surface tension was in all cases 27 mN/m but was reached at a higher surfactant concentration for the BSA/ C12E5solution than for the pure surfactant or the lysozyme/surfactant mixture, indicating that C12E5binds to BSA but not to lysozyme. It was estimated that BSA bound four to five molecules of C12E5. Only BSA seemed to have any large effect on the cloud point of the surfactant and above a certain critical protein to surfactant ratio the clouding is totally suppressed. The results implies that the presence of protein influences the clouding only if surfactant binds to the protein.

ISSN:0193-2691    

DOI:10.1080/01932699708943747

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0193-2691    

DOI:10.1080/01932699708943748

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor