Influence de divers param�tres de constitution et de composition sur la configuration du domaine d'existence et certaines propri�t�s de microemulsions quaternaires monophasiques

Abstract

Macroscopically homogeneous, stable, fluid, generally optically transparent and isotropic media (currently called "microemulsions") may be formed by adequately mixing together water, a hydrophobic hydrocarbon, ("oil"), and suitable amphiphilic substances. The microemulsion domains of numerous systems incorporating water, sodium dodecylsulfate, various straight or branched alkanols and various aliphatic or aromatic hydrocarbons were delineated at T = 25 ~ It has thus been possible to bring out the influence of several composition factors upon microemulsion domain configuration, i. e. straight alkanol number of carbon atoms, alkanol isomery, normal aliphatic hydrocarbon number of carbon atoms, aliphatic hydrocarbon-aromatic hydrocarbon substitution. The existence of two main kinds of water/ionic surfactant/alkanol/hydrocarbon systems, according as the microemulsion realm-of-existence in the phase tetrahedron consists of two disjoined volumes, ("long" alkanols), or forms an all-in-one block volume, ("short" alkanols), can well be correlated with the existence of striking dissimilarifles in certain transport properties of microemulsions, such as electrical conductivity or viscosity. For some "short" alkanols, (e. g. 1-pentanol or 2-pentanol), the microemulsion domains exhibits strange configuration irregularities. Results gained from studies of microemulsion electroconductive and viscous behavior and of cyclohexene-2-one-lphotodimerization in microemulsions tend to indicate that these configuration irregularities define certain ranges of system composition that correspond to microemulsions possessing an exotic structure.Key words: Water, sodium dodecylsulfate, straight and branched alkanols, afiphatic and aromatic hydrocarbons, cyclohexene-2-one-1, microemulsion(s).Des milieux tr~s divers par le nombre et la nature des phases qui les composent, lorsque l'~quilibre thermodynamique est atteint, peuvent ~tre form,s en m~langeant de l'eau, (ou une solution saline aqueuse), un liquide hydrophobe tel qu'un hydrocarbure aliphatique ou aromatique et une (ou plusieurs) substance