Study On The Solubilization Of Organics In Winsor Type ? Microemulsions

With low interfacial tension and strong emulsifying capacity,microemulsion shows good solubilization ability on organic matter.In this paper,several hydrocarbon organic compounds were studied,and the law of solubilization of organic compounds was investigated.Winsor type III microemulsions were prepared using sodium dodecyl sulfate(SDS)as surfactant,n-butanol as co-surfactant,NaCl as salt,for different organic mixtures(binary mixture of n-hexane,cyclohexane,toluene or n-octane).Gas chromatography was used to measure the organics content in the excess oil phase of Winsor type III microemulsion.The partition of organics under different surfactant and NaCl concentrations and different composition and content of organics mixtures was studied.The results show that the content is different for organics in the excess oil phases and in the initial organic mixtures,which means that selectivity was occurred during solubilization.Volume ratio of toluene to n-octane after solubilization increased by 1.4356 times,1.1400 times,0.9915 times,0.5285 times,0.4226 times and 0.2001 times at SDS content of 3.0%,4.0%,5.0%,6.0%,7.0%,10.0%.Volume ratio of toluene to n-octane after solubilizing increased by 0.0158 times,0.0532 times,0.0475 times and0.2099 times at NaCl content of 3.0%,4.0%,5.0%,6.0%.In general,molecules which have smaller molecular volume and light polarity are preferentially solubilized.The solubilization behavior of mixed oils was examined using two kinds of surfactants,octadecyl trimethyl ammonium chloride(OTAC)and SDS.Equivalent alkyl carbon number(EACN)was adjusted through mixing of different kinds of hydrocarbons,including two-component and four-component hydrocarbons.The relations between EACN and the optimum dosage of alcohol(A*)and optimal solubilization parameter(SP*)were investigated.It was found that for both of the two kinds of surfactants used,the A*vs.EACN and the SP*vs.EACN relations fit quadratic functions.For a certain surfactant under constant condition,the quadratic functions are the same no matter what kinds of hydrocarbons were used.Relationship between optimal relative amount of alcohol and the equivalent alkyl carbon number in octadecyl trimethyl ammonium chloride microemulsion system is A*=0.0101(EACN)~2-0.0846(EACN)+0.8357,relationship between optimal solubilization ability and EACN is SP*=0.3872(EACN)~2-9.6179(EACN)+62.732.Relationship between optimal relative amount of alcohol and the equivalent alkyl carbon number(EACN)in SDS microemulsion system is A*=0.0405(EACN)~2-0.2552(EACN)+1.4074,relationship between optimal solubilization ability and the equivalent alkyl carbon number is SP*=-0.2457(EACN)~2+1.5048(EACN)+5.9264.