Ion SANDU1, 2, 3, 4, Adrian Valentin COTIRLET1, 5, Gogu GHIORGHITA1, Roxana CURCA1,3, Andrei Victor SANDU1,2,4,6*
Abstract. The effects of the surfactant adsorption on the surface of a free liquid drop, immersed in an unbounded liquid (the densities of the two bulk liquids are equal) are studied. The interfacial tension gradients, caused by the surfactant applied on the drop surface, generate surface forces within the boundary region of the free drop, leading to a surface flow (known as Marangoni flow). As a result of this flow, which causes the motion of neighboring liquids by viscous traction, a hydrodynamic pressure force (named Marangoni force) is generated which acts on the free drop surface. The aim of this research study is to correlate the effects of interfacial tension gradients, in a real surface flow, with the forces of hydrodynamic pressure, acting on the free drop surface. The Marangoni force is examined on nondeformable and deformable free drops. Dynamics of free liquid drops is known as the interfacial Marangoni effect. This effect has an important impact on surface flow of liquids in the absence of gravity, as well as in advanced fundamental research in physical chemistry, colloidal science, biological phenomena and in medical applications.
Keywords: free drop dynamics, interfacial tension gradient, Marangoni force, Marangoni effect, Marangoni flow, hydrodynamic model
DOI 10.56082/annalsarsciphyschem.2025.2.43
1 Academy of Romanian Scientists, 3 Ilfov St., RO-050044, Bucharest, Romania
2 National Institute for Research and Development in Environmental Protection, Splaiul Independenței, nr. 294, Sector 6, 060031 Bucharest, Romania
3 Alexandru Ioan Cuza University of Iasi, Science Department, Interdisciplinary Research Institute, Bld. Carol I, nr. 11, 700506 Iasi, Romania
4 Romanian Inventors Forum, Str. Sf. Petru Movilă, nr. 3, L11, III/3, 700089 Iași, Romania
5 Moinești Municipal Emergency Hospital, str. Zorilor, nr. 1, 605400 Moinești, Bacău, Romania
6 Gheorghe Asachi Technical University of Iasi, The Faculty of Material Science and Engineering, Bld. D. Mangeron, nr. 61, 700050 Iasi, Romania
* Corresponding author: ion.sandu@uaic.ro
PUBLISHED in Annals of the Academy of Romanian Scientists Series on Physics and Chemistry, Volume 10, No2