Brownian dynamics of colloidal microspheres with tunable elastic properties from soft to hard
- Yoon, Jiwon Department of Physics, University of Fribourg, Switzerland - School of Chemical Engineering, Seoul National University, South Korea
- Cardinaux, Frédéric Department of Physics, University of Fribourg, Switzerland
- Lapointe, Clayton P. Department of Physics, University of Fribourg, Switzerland
- Zhang, Chi Department of Physics, University of Fribourg, Switzerland
- Mason, Thomas G. Department of Chemistry and Biochemistry, University of California, Los Angeles, USA - Department of Physics and Astronomy, University of California, Los Angeles, USA
- Ahn, Kyung Hyun School of Chemical Engineering, Seoul National University, South Korea
- Scheffold, Frank Department of Physics, University of Fribourg, Switzerland
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05.06.2018
Published in:
- Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 2018, vol. 546, p. 360–365
English
We study the Brownian thermal motion of a colloidal model system made by emulsifying hot liquid α-eicosene wax into an aqueous surfactant solution of sodium dodecyl sulfate (SDS). When this waxy oil-in-water emulsion is cooled below α- eicosene's melting point of Tc ≃ 25 °C, the microscale emulsion droplets solidify, effectively yielding a dispersed particulate system. So, the interiors of these wax droplets can be tuned from a viscous liquid to an elastic solid through very modest changes in absolute temperature. Using the multiple light scattering technique of diffusing wave spectroscopy (DWS), which is very sensitive to small-scale motion and shape fluctuations of dispersed colloidal objects, we show that the thermal fluctuations of the interfaces of these liquid droplets at higher temperature, seen in the DWS intensity–intensity correlation function at early times, effectively disappear when these droplets solidify at lower temperature. Thus, we show that the early-time behavior of this DWS correlation function can be used to probe mechanical properties of viscoelastic soft materials dispersed as droplets.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Physique
- Language
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- English
- Classification
- Physics
- License
- License undefined
- Identifiers
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- RERO DOC 322579
- DOI 10.1016/j.colsurfa.2018.02.046
- Persistent URL
- https://folia.unifr.ch/unifr/documents/307180
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