Simultaneous study of molecular and micelle diffusion in a technical microemulsion system by dynamic light scattering
Matthias Samuel Günter Knoll1, Cédric Giraudet1, Christian Joachim Hahn2
1Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP), Department of Chemical and Biological Engineering (CBI) and Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Paul-Gordan-Straße 6, 91052 Erlangen, Germany.
Journal of Colloid and Interface Science
|March 5, 2019
Summary
Dynamic light scattering (DLS) simultaneously measured molecular and micelle diffusion in microemulsions. Results show diffusion coefficients increase with temperature, with CO2 influencing molecular diffusion.
Area of Science:
- Physical Chemistry
- Materials Science
Background:
- Dynamic Light Scattering (DLS) is a standard technique for measuring diffusion coefficients.
- Simultaneous determination of molecular and micelle diffusion has not been previously reported.
Purpose of the Study:
- To investigate simultaneous measurement of molecular and translational micelle diffusion using DLS.
- To analyze diffusion in microemulsions and their subsystems with varying temperatures and pressures.
Main Methods:
- Systematic investigation of microemulsions and subsystems using DLS.
- Experiments conducted at temperatures of 314, 333, and 353 K and pressures of 10, 13, and 16 MPa.
Main Results:
- Simultaneous measurement of molecular and translational micelle diffusion coefficients was achieved.
- Diffusion coefficients increased with temperature; hydrodynamic diameter increased with CO2 swelling.
- Molecular diffusion, observable with CO2, was largely unaffected by surfactant presence.
Conclusions:
- DLS can simultaneously determine molecular and micelle diffusion coefficients.
- CO2 plays a significant role in molecular diffusion within these microemulsion systems.
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