Colloidal motion under the action of a thermophoretic force
The Journal of Chemical Physics
MetadataShow full item record
Burelbach, J., Zupkauskas, M., Lamboll, R., Lan, Y., & Eiser, E. (2017). Colloidal motion under the action of a thermophoretic force. The Journal of Chemical Physics, 147 (9. 094906)https://doi.org/10.1063/1.5001023
We present thermophoretic measurements in aqueous suspensions of three different polystyrene (PS) particles of varying negative charge, size, and surface coating. Our measurement technique is based on the observation of the colloidal steady-state distribution using conventional bright-field microscopy, which avoids undesirable effects such as laser-induced convection or local heating. We find that the colloids with the weakest zeta potential exhibit the strongest thermophoretic effect, suggesting that the Soret coefficient has a more intricate dependence on surface functionality than predicted by existing theoretical approaches. We also study the relaxation of the colloids to steady-state and propose a model to quantify the relaxation speed, based on the time evolution of the colloidal center of mass. Our observations are well described by this model and show that the relaxation speed tends to increase with the magnitude of the thermophoretic force.
This work was funded by the Winton Programme for the Physics of Sustainability, Unilever Case and EPSRC (Grant No. 1353070).
Embargo Lift Date
External DOI: https://doi.org/10.1063/1.5001023
This record's URL: https://www.repository.cam.ac.uk/handle/1810/270272
Attribution 4.0 International
Licence URL: http://creativecommons.org/licenses/by/4.0/
Recommended or similar items
The following licence files are associated with this item: