%0 Journal Article
%A Naumann, Philipp
%A Datta, Sascha
%A Sottmann, Thomas
%A Arlt, Bastian
%A Frielinghaus, Henrich
%A Wiegand, Simone
%T Isothermal Behavior of the Soret Effect in Nonionic Microemulsions: Size Variation by Using Different n -Alkanes
%J The journal of physical chemistry  / B
%V 118
%N 12
%@ 1520-5207
%C Washington, DC
%I Soc.
%M FZJ-2014-01958
%P 3451 - 3460
%D 2014
%X In this work we investigate the thermodiffusion behavior of microemulsiondroplets of the type H2O/n-alkane/C12E5 (pentaethylene glycol monododecylether) using the n-alkanes: n-octane, n-decane, n-dodecane, and n-tetradecane. In orderto determine the thermodiffusion behavior of these microemulsion droplets, we applythe infrared thermal diffusion forced Rayleigh scattering (IR-TDFRS) technique. Wemeasure the Soret coefficient (ST) as function of the structure upon approaching theemulsification failure boundary (efb) and as a function of the radius of the spherical o/wmicroemulsion droplets close to the efb. By varying the chain length of the n-alkanes, weare able to study the thermodiffusion behavior of spherical o/w microemulsion dropletsof different sizes at the same temperature. In the investigated range a linear dependenceof the Soret coefficient as function of the radius was found. By use of a proposedrelationship between the Soret coefficient and the temperature dependence of theinterfacial tension, the transition layer l could be determined for the first time.Additionally, small angle neutron scattering (SANS) experiments are performed todetermine the size and to prove that the shape of the microemulsion droplets is spherical close to the efb. Accordingly, thescattering curves could be quantitatively described by a combination of a spherical core−shell form factor and sticky hard spherestructure factor.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000333578000023
%R 10.1021/jp412126n
%U https://juser.fz-juelich.de/record/152184