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Surfactant-enhanced spreading: experimental achievements and possible mechanisms
journal contribution
posted on 2015-11-03, 14:07 authored by Nina Kovalchuk, Anna TrybalaAnna Trybala, Omid Arjmandi-Tash, Victor StarovSurfactants 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 ScienceCitation
KOVALCHUK, N. ...et al., 2016. Surfactant-enhanced spreading: experimental achievements and possible mechanisms. Advances in Colloid and Interface Science, 233, pp.155-160.Publisher
© ElsevierVersion
- 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
2015-08-10Notes
This paper is in closed access.ISSN
0001-8686eISSN
1873-3727Publisher version
Language
- en