TY  - CONF
AU  - Naumann, Philipp
AU  - Wiegand, Simone
AU  - Sottmann, Thomas
TI  - Isothermal Behavior of the Soret Effect in Nonionic Microemulsions: Size Variation by Using Different n-Alkanes
M1  - FZJ-2015-02256
PY  - 2014
AB  - In this work we investigate the thermodiffusion behavior of microemulsion droplets of the type H2O / n-alkane / C12E5  using the n-alkanes: n-octane, n-decane, n-dodecane and n-tetradecane [1]. In order to determine the thermodiffusion behavior of these microemulsion droplets, we apply the infrared thermal diffusion forced Rayleigh scattering technique. We measure the Soret coefficient S_T as function of the structure upon approaching the emulsification failure boundary (efb) and as a function of the radius of the spherical o/w-microemulsion droplets close to the efb. By varying the chain length of the n-alkanes we are able to study the thermodiffusion behavior of  droplets of different sizes at the same temperature. In the investigated range a linear dependence of the Soret coefficient as function of the radius  was found. Using a proposed relationship between the Soret coefficient and the temperature dependence of the interfacial tension, the  transition layer, l, could be determined for the first time [2].Additionally, small angle neutron scattering (SANS) experiments are performed to determine the size and to examine in detail the shape of the microemulsion droplets, as the droplets are known to elongate with increasing temperature. Close to the efb the scattering curves could be quantitatively described by a combination of a spherical core-shell form factor and sticky hard sphere structure factor. [1] Naumann, P., Datta, S., Sottmann, T., Arlt, B., Frielinghaus, H. and Wiegand, S. Submitted to J. Phys. Chem.B.[2] Parola, A. and Piazza, R.; Particle Thermophoresis in Liquids Eur. Phys. J. E., 15, pp. 255-263, 2004.
T2  - International Meeting on Thermodiffusion 11
CY  - 1 Jun 2014 - 6 Jun 2014, Bayonne (France)
Y2  - 1 Jun 2014 - 6 Jun 2014
M2  - Bayonne, France
LB  - PUB:(DE-HGF)6
UR  - https://juser.fz-juelich.de/record/188972
ER  -