title: On the composition fluctuations of reverse micelles.
abstract: The polydispersity of the reverse micelles is determined mainly by the fluctuations of their composition. The composition of the reverse micelle is a two-dimensional random variable whose components are the numbers of water (i) and surfactant (j) molecules. In this study the fluctuations of the composition of the reverse micelles are considered in the Gaussian approximation. It is shown that the standard deviation of the quantity w=i/j may be calculated from the dependence of the water vapor pressure above the microemulsion on the molar ratio W=[water]/[surfactant]. The estimation based on the literature data for microemulsion system sodium bis(2-ethylhexyl)sulfosuccinate/water/isooctane at 37°C in the range W=0-18 has shown that the relative standard deviation of the quantity w is about 10%. It is shown that the value of the composition fluctuations is related to the dependence of average composition on the concentration of reverse micelles at constant parameter W.
authors.affiliation: Institute of Problems of Chemical Physics, Russian Academy of Sciences, Acad. Semenov Av. 1, Chernogolovka, Moscow Region 142432, Russia. tovstun@icp.ac.ru
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Tovstun
authors.forename: Vladimir F
authors.initials: VF
authors.lastname: Razumov
mesh_terms: D004143:Dioctyl Sulfosuccinic Acid / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D008823:Micelles; D009795:Octanes / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004655:Emulsions; D008823:Micelles; D009795:Octanes; D013501:Surface-Active Agents; D014867:Water; D004143:Dioctyl Sulfosuccinic Acid; C045798:2,2,4-trimethylpentane