Observation of two diffusive relaxation modes in microemulsions by dynamic light scattering

Langmuir : the ACS Journal of Surfaces and Colloids
Anuj ShuklaReinhard H H Neubert

Abstract

Water-in-oil microemulsions stabilized by AOT and dispersed in n-alkane oils with a constant molar water-to-surfactant ratio were studied by dynamic light scattering. A dilution series (in the range of volume fraction of water plus surfactant, phi approximately 0.02-0.52) was used, which allowed us to extract information about droplet sizes, diffusion coefficients, interactions, and polydispersity from experimental data. We report the observation of two diffusive relaxation modes in a concentrated microemulsion (0.20 < phi < 0.5) due to density (collective diffusion) and concentration or polydispersity (self-diffusion) fluctuations. Below this concentration it was difficult to resolve two exponentials unambiguously, and in this case one apparent relaxation mode was observed. It was found that for a given composition self-diffusion is more pronounced in apparent relaxation mode for a shorter chain length alkane. The concentration dependence of these diffusion coefficients reflects the effect of hard sphere and the supplementary attractive interactions. It was observed that the attractive part becomes more pronounced in the case of a large alkane chain oil at a given temperature. This explains the shift of the region of microemul...Continue Reading

References

Nov 15, 1990·Physical Review. a·B Cichocki, B U Felderhof
May 1, 2001·Physical Review Letters·U PeterA K Sood

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Citations

Feb 1, 2011·Physical Chemistry Chemical Physics : PCCP·Jorge Carballido-LandeiraAlberto P Muñuzuri
Dec 4, 2012·Journal of Colloid and Interface Science·Kévin Tse-Ve-KoonÉric Freyssingeas
Jun 14, 2012·European Journal of Pharmaceutics and Biopharmaceutics : Official Journal of Arbeitsgemeinschaft Für Pharmazeutische Verfahrenstechnik E.V·Fitsum F SahleReinhard H H Neubert
Jun 17, 2015·The European Physical Journal. E, Soft Matter·Lamiae TalhaLuca Cipelletti
Jul 31, 2013·European Journal of Pharmaceutics and Biopharmaceutics : Official Journal of Arbeitsgemeinschaft Für Pharmazeutische Verfahrenstechnik E.V·Fitsum F SahleReinhard H H Neubert
Dec 3, 2014·International Journal of Pharmaceutics·Ajaya Bhattarai, Hanna Wilczura-Wachnik
Mar 16, 2007·Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics·Y HattoriP Panizza
Dec 13, 2016·Langmuir : the ACS Journal of Surfaces and Colloids·Tianxiang YinWeiguo Shen
Jul 21, 2006·The Journal of Physical Chemistry. B·Jacqueline AppellEric Buhler

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