Flow regime transitions and effects on solute transport in surfactant-driven Marangoni flows

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:553

Article

Iasella, Steven V.¹  Sun, Ningguan¹  Zhang, Xin¹  Corcoran, Timothy E.²  Garoff, Stephen³  Przybycien, Todd M.^1,4,5  Tilton, Robert D.^1,4 

[1] Carnegie Mellon Univ, Dept Chem Engn, Ctr Complex Fluids Engn, 5000 Forbes Ave, Pittsburgh, PA 15213 USA

[2] Univ Pittsburgh, Dept Med, Pulm Allergy & Crit Care Div, 3550 Terrace St, Pittsburgh, PA 15213 USA

[3] Carnegie Mellon Univ, Dept Phys, Ctr Complex Fluids Engn, 5000 Forbes Ave, Pittsburgh, PA 15213 USA

[4] Carnegie Mellon Univ, Dept Biomed Engn, Ctr Complex Fluids Engn, 5000 Forbes Ave, Pittsburgh, PA 15213 USA

[5] Rensselaer Polytech Inst, Dept Chem & Biol Engn, 110 8th St, Troy, NT 12180, Australia

关键词: Marangoni flow;    Spreading;    Surfactants;    Liquid films;    Dewetting;   

DOI  :  10.1016/j.jcis.2019.06.016

来源: Elsevier

【 摘 要 】

Hypothesis: Surfactant-driven Marangoni flow on liquid films is predicted to depend on subphase depth and initial surface tension difference between the subphase and deposited surfactant solution drop. Changes in flow behavior will impact transport of soluble species entrained in the Marangoni flow along the surface. In extreme cases, the subphase film may rupture, limiting transport. Understanding this behavior is important for applications in drug delivery, coatings, and oil spill remediation. Experiments: A trans-illumination optical technique measured the subphase height profiles and drop content transport after drop deposition when varying initial subphase depth, surfactant concentration, and subphase viscosity. Findings: Three distinct flow regimes were identified depending on the subphase depth and surfactant concentration and mapped onto an operating diagram. These are characterized as a central depression bounded by an outwardly traveling ridge, an annular depression bounded by a central dome and the traveling ridge, and an annular dewetting when the subphase ruptures. Well above the critical micelle concentration, transitions between regimes occur at characteristic ratios of gravitational and initial surface tension gradient stresses: transitions shift when surfactant dilution during spreading weakens the stress before the completion of the spreading event. Drop contents travel with the ridge, but dewetting hinders transport. (C) 2019 Elsevier Inc. All rights reserved.

【 授权许可】

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