Spreading and retraction dynamics of sessile evaporating droplets comprising volatile binary mixtures
| Autor: | Adam Williams, Dimitrios Mamalis, George Karapetsas, Omar Matar, Prashant Valluri, Khellil Sefiane |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Fluids & Plasmas media_common.quotation_subject Evaporation 02 engineering and technology Substrate (electronics) Inertia 01 natural sciences Instability 09 Engineering Physics::Fluid Dynamics Stress (mechanics) 0103 physical sciences 010306 general physics 01 Mathematical Sciences media_common Marangoni effect Mechanical Engineering 021001 nanoscience & nanotechnology Condensed Matter Physics Lubrication theory Condensed Matter::Soft Condensed Matter Mechanics of Materials Chemical physics Wetting 0210 nano-technology |
| Zdroj: | Journal of Fluid Mechanics Williams, A G L, Karapetsas, G, Mamalis, D, Sefiane, K, Matar, O K & Valluri, P 2021, ' Spreading and retraction dynamics of sessile evaporating droplets comprising volatile binary mixtures ', Journal of Fluid Mechanics, vol. 907, A22 . https://doi.org/10.1017/jfm.2020.840 |
| ISSN: | 1469-7645 0022-1120 |
| DOI: | 10.1017/jfm.2020.840 |
| Popis: | The dynamics of thin volatile droplets comprising of binary mixtures deposited on a heated substrate are investigated. Using lubrication theory, we develop a novel one-sided model to predict the spreading and retraction of an evaporating sessile axisymmetric droplet formed of a volatile binary mixture on a substrate with high wettability. A thin droplet with a moving contact line is considered, taking into account the variation of liquid properties with concentration as well as the effects of inertia. The parameter space is explored and the resultant effects on wetting and evaporation are evaluated. Increasing solutal Marangoni stress enhances spreading rates in all cases, approaching those of superspreading liquids. To validate our model, experiments are conducted with binary ethanol–water droplets spreading on hydrophilic glass slides heated from below. The spreading rate is quantified, revealing that preferential evaporation of the more volatile component (ethanol) at the contact line drives superspreading, leading in some cases to a contact line instability. Good qualitative agreement is found between our model and experiments, with quantitative agreement being achieved in terms of spreading rate. |
| Databáze: | OpenAIRE |
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