摘要:

Polyglyceryl oleates with 3,6,10 glycerol groups formed lamellar liquid crystal with water. The penetration of water into amphiphilic bilayer was reduced with increased the number of glycerol groups. Polyglyceryl oleate entered into a liquid crystalline model of the stratum corneum lipids reduced the penetration of water and enhanced the stability towards low water content.

ISSN:0193-2691    

DOI:10.1080/01932690008913242

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In this manuscript, Aspirin and 2,4-dinitrochlorobenzene were used as substrates of hydrolysis reactions. The hydrolysis kinetics of the two substrates in microemulsion system for CTAB/n-butanol/25%n-octane/water was studied by using UV method, and the mechanism of the hydrolysis in different microemulsion media, especial the one of aspirin, was discussed. All experimental results showed that the hydrolysis reaction was extremely affected by the structures and the structural transitions of microemulsions. The hydrolysis rates are higher in the water in Oil(W/O) microemulsion media and decrease with the addition of water, in bicontinuous(B.C), they increase with the addition of water, and decrease in the oil in water(O/W). The transition points of the hydrolysis rates occurred just at structural transition points from W/O to B.C. in the microemulsions and from BC. to O/W. The phenomenon was considered to be caused by the different hydrolysis mechanisms in the different microemulsion media and the change of the polarity in “the interfacial films” of microemulsions. The aim of the investigation is to establish what is the connection between the structures of microemulsions and the hydrolysis rates.

ISSN:0193-2691    

DOI:10.1080/01932690008913243

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The stability and the rheological properties of emulsions prepared with saccharose esters were studied regarding the amounts of the two emulsifiers used and their HLB. The satisfactory stability of these systems has been ascribed to the presence of α-gel phases, evidenced by polarised light microscopy and studied by rheological and water evaporation measurements. The possibility of enclosing pigments such as TiO; and ZnO in these emulsions has also been verified.

ISSN:0193-2691    

DOI:10.1080/01932690008913244

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Ti-MCM-48 mesoporous materials have been synthesized by sequential addition of alkoxides. The atomic ratio of Si and Ti in the synthesis gel was 40 and 5, respectively. The materials were characterized by means of powder XRD, N2adsorption-desorption measurements. HREM,29Si MAS NMR, diffuse reflectance FT-IR spectroscopy, electrophoretic mobility measurements and electron probe microanalysis.

ISSN:0193-2691    

DOI:10.1080/01932690008913245

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The phase diagram of water, phenethyl alcohol (PEA) and the triblock copolymer EO4.5PO59EO4.5, (EO = ethylene oxide, PO = propylene oxide), L101, was determined and the vapor pressures of PEA were measured for different phases.

ISSN:0193-2691    

DOI:10.1080/01932690008913246

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The amphiphilic association structures in the system water-phenethyl alcohol and two triblock copolymers (L101: EO4.5PO59EO4.5and F108: EO132.5PO50EO132.5) (EO=ethylene oxide, PO=propylene oxide) were investigated by optical observation, measurements of surface tension, quasi-elastic light scattering and electric conductance. The results showed a most drastic influence of small amounts of the long polar chain block copolymer on the phase regions in the system water-phenethyl alcohol - (EO)5(PO)56(EO)5with 0.1% of the long polar chain compound added to the short chain one giving a most pronounced change in the phase regions.

ISSN:0193-2691    

DOI:10.1080/01932690008913247

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Materials which display ionic conductivity were produced by the sol-gel and microemulsion-gel methods. The charging and discharging characteristics were investigated and it was found that a single ionic species was responsible for the conduction, the ionic species being residual protons from the initial component mixture. The complex impedence of various samples was measured and the ionic conductivities ranged in value from 9 × 10−8to 1 × 10−5ohm−1cm−1. An Arrhemius plot for a microemulsion-gel revealed that the energy of activation was 0.15 eV.

ISSN:0193-2691    

DOI:10.1080/01932690008913248

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor