Nonisothermal Spreading Dynamics of Self-Rewetting Droplets

We experimentally studied the spreading dynamics of binary alcohol mixtures (and pure liquids for reference) deposited on a heated substrate in a partially wetting situation under nonisothermal conditions. We show that the spreading mechanism of an evaporating droplet exhibits a power-law growth wit...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 34(2018), 5 vom: 06. Feb., Seite 1916-1931
1. Verfasser: Mamalis, Dimitrios (VerfasserIn)
Weitere Verfasser: Koutsos, Vasileios, Sefiane, Khellil
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2018
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't
Beschreibung
Zusammenfassung:We experimentally studied the spreading dynamics of binary alcohol mixtures (and pure liquids for reference) deposited on a heated substrate in a partially wetting situation under nonisothermal conditions. We show that the spreading mechanism of an evaporating droplet exhibits a power-law growth with early-stage exponents that depend strongly and nonmonotonically on the substrate temperature. Moreover, we investigated the temporal and spatial thermal dynamics in the droplet using infrared thermography, revealing the existence of unique thermal patterns due to thermal and/or solutal instabilities, which lead to surface tension gradients, namely the Marangoni effect. Our key findings are that the temperature of the substrate drastically affects the early-stage inertial-capillary spreading regime owing to the nonmonotonic surface tension-temperature dependence of the self-rewetting liquids. At later stages of wetting, the spreading dynamics enters the viscous-capillary dominated regime, with the characteristic low kinetics mirroring the behavior of pure liquids
Beschreibung:Date Completed 03.05.2018
Date Revised 03.05.2018
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.7b04045