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Surfactant-enhanced spreading: experimental achievements and possible mechanisms

journal contribution
posted on 03.11.2015, 14:07 by Nina Kovalchuk, Anna TrybalaAnna Trybala, Omid Arjmandi-Tash, Victor Starov
Surfactants are broadly used to improve wetting properties of aqueous formulations. The improvement is achieved by essential reduction of liquid/air and solid/liquid interfacial tensions resulting in the decrease of contact angle. For moderately hydrophobic substrates, there is a range of surfactants providing complete wetting of substrate. With the decrease of substrate surface energy, this range of surfactants reduces very quickly and only trisiloxane surfactant solutions are capable to wet completely such highly hydrophobic substrates as polypropylene and parafilm. That is why these surfactants are referred to as superspreaders. The most intriguing feature of wetting surfactant solutions is their ability to spread much faster than pure liquids with spread area, S, being proportional to time, t, S~t, as compared to S~t(0.2) for pure liquids, which wet completely the solid substrate. Trisiloxane surfactant solutions spread faster than other aqueous surfactant solutions, which also provide complete wetting, being superspreaders in the sense of spreading rate as well. The mechanism of fast spreading of surfactant solutions on hydrophobic substrates and much higher spreading rates for trisiloxane solutions are to be explained. Below the available experimental data on superspreading and surfactant-enhanced spreading are analysed/summarised, and possible mechanisms governing the fast spreading are discussed.

Funding

This work was supported by Engineering and Physical Sciences Research Council, UK, grant EP/D077869/1; CoWet EU project; ESA under grants EVAPORATION, FASES, and PASTA and by COST MP1106 project.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Published in

Advances in Colloid and Interface Science

Citation

KOVALCHUK, N. ...et al., 2016. Surfactant-enhanced spreading: experimental achievements and possible mechanisms. Advances in Colloid and Interface Science, 233, pp.155-160.

Publisher

© Elsevier

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2015-08-10

Notes

This paper is in closed access.

ISSN

0001-8686

eISSN

1873-3727

Language

en