Marangoni Effects in Liquid Jets of Non-Ionic Surfactants

Daniel M. Colegate; Colin D. Bain

doi:10.1071/CH05136

RESEARCH ARTICLE

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Marangoni Effects in Liquid Jets of Non-Ionic Surfactants

Daniel M. Colegate ^A and Colin D. Bain ^A ^B

+ Author Affiliations

- Author Affiliations

^A Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK.

^B Corresponding author. Email: colin.bain@chem.ox.ac.uk

Australian Journal of Chemistry 58(9) 678-682 https://doi.org/10.1071/CH05136
Submitted: 1 June 2005 Accepted: 5 July 2005 Published: 21 September 2005

Abstract

The adsorption of nonionic surfactants in the C_nE₈ family at the air–water interface has been studied on the millisecond timescale in a free liquid jet. The amount of adsorbed surfactant was measured by ellipsometry. The rates of adsorption are compared with a diffusion-controlled adsorption model. In the case of C₁₀E₈, which is below its cmc, the monomer diffusion coefficient provides a good fit to the experimental data. For n = 12, 14, and 16, micelles control the mass transport. The best fit diffusion coefficients are close to, but not identical with, the literature values for the micellar diffusion coefficients. Laser Doppler velocimetry was used to measure the change in surface velocity arising from adsorption of the surfactant, for n = 12, 14, and 16. There was a qualitative correlation between the retardation of the surface velocity and the surface tension gradients.

Acknowledgments

We thank T. Battal for acquiring the data on C₁₀E₈ and the Mathematical and Physical Sciences Division of the University of Oxford for financial support. The experimental rig was constructed under EPSRC grant GR/M73194.

References

Marangoni Effects in Liquid Jets of Non-Ionic Surfactants

Abstract

Acknowledgments

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