Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-23T09:09:47.290Z Has data issue: false hasContentIssue false

Effect of interfacial viscosities on droplet migration at low surfactant concentrations

Published online by Cambridge University Press:  03 September 2020

Rajat Dandekar
Affiliation:
School of Mechanical Engineering, Purdue University, West Lafayette, IN49707, USA
Arezoo M. Ardekani*
Affiliation:
School of Mechanical Engineering, Purdue University, West Lafayette, IN49707, USA
*
Email address for correspondence: [email protected]

Abstract

In this paper, we theoretically investigate the migration of a surfactant covered droplet in a Poiseuille flow by including the surface viscosities of the droplet. We employ a regular perturbation expansion for low surface Péclet numbers and solve the problem up to a second-order approximation. We represent the drop surface as a two-dimensional homogeneous fluid using the Bousinessq–Scriven law and employ Lamb's general solution to represent the velocity fields inside and outside the droplet. We obtain an expression for the cross-stream migration velocity of the droplet, where the surface viscosities are captured by the Bousinessq numbers for surface shear and surface dilatation. We elucidate the influence of the surface viscosities on the migration characteristics of the droplet and the surfactant redistribution on the droplet surface. Our study sheds light on the importance of including the droplet surface viscosities to accurately predict the migration characteristics of the droplet.

Type
JFM Papers
Copyright
© The Author(s), 2020. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Asmolov, E. S. 1999 The inertial lift on a spherical particle in a plane Poiseuille flow at large channel Reynolds number. J. Fluid Mech. 381, 6387.CrossRefGoogle Scholar
Bhamla, M. S., Chai, C., Alvarez-Valenzuela, M. A., Tajuelo, J. & Fuller, G. 2017 Interfacial mechanisms for stability of surfactant-laden films. PloS One 12 (5), e0175753.CrossRefGoogle ScholarPubMed
Boussinesq, M. J. 1913 Sur l'existence d'une viscosité superficielle, dans la mince couche de transition séparant un liquide d'un autre fluide contigu. Ann. Chim. Phys 29, 349357.Google Scholar
Chan, P. H. & Leal, L. G. 1979 The motion of a deformable drop in a second-order fluid. J. Fluid Mech. 92 (1), 131170.CrossRefGoogle Scholar
Cox, R. G. & Brenner, H. 1968 The lateral migration of solid particles in Poiseuille flow – I theory. Chem. Engng Sci. 23 (2), 147173.CrossRefGoogle Scholar
Das, S., Mandal, S. & Chakraborty, S. 2017 Cross-stream migration of a surfactant-laden deformable droplet in a Poiseuille flow. Phys. Fluids 29 (8), 082004.CrossRefGoogle Scholar
Di Carlo, D., Irimia, D., Tompkins, R. G. & Toner, M. 2007 Continuous inertial focusing, ordering, and separation of particles in microchannels. Proc. Natl Acad. Sci. 104 (48), 1889218897.CrossRefGoogle ScholarPubMed
Gascoyne, P., Satayavivad, J. & Ruchirawat, M. 2004 Microfluidic approaches to malaria detection. Acta Trop. 89 (3), 357369.CrossRefGoogle ScholarPubMed
Gounley, J., Boedec, G., Jaeger, M. & Leonetti, M. 2016 Influence of surface viscosity on droplets in shear flow. J. Fluid Mech. 791, 464494.CrossRefGoogle Scholar
Gupta, L. & Wasan, D. T. 1974 Surface shear viscosity and related properties of adsorbed surfactant films. Ind. Engng Chem. Fundam. 13 (1), 2633.CrossRefGoogle Scholar
Haber, S. & Hetsroni, G. 1971 The dynamics of a deformable drop suspended in an unbounded Stokes flow. J. Fluid Mech. 49 (2), 257277.CrossRefGoogle Scholar
Hanna, J. A. & Vlahovska, P. M. 2010 Surfactant-induced migration of a spherical drop in Stokes flow. Phys. Fluids 22 (1), 013102.CrossRefGoogle Scholar
Hetsroni, G. & Haber, S. 1970 The flow in and around a droplet or bubble submerged in an unbound arbitrary velocity field. Rheol. Acta 9 (4), 488496.CrossRefGoogle Scholar
Ho, B. P. & Leal, L. G. 1974 Inertial migration of rigid spheres in two-dimensional unidirectional flows. J. Fluid Mech. 65 (2), 365400.CrossRefGoogle Scholar
Karimi, A., Yazdi, S. & Ardekani, A. M. 2013 Hydrodynamic mechanisms of cell and particle trapping in microfluidics. Biomicrofluidics 7 (2), 021501.CrossRefGoogle ScholarPubMed
Leal, L. 2007 Advanced Transport Phenomena: Fluid Mechanics and Convective Transport Processes, vol. 7. Cambridge University Press.CrossRefGoogle Scholar
Mandal, S., Bandopadhyay, A. & Chakraborty, S. 2015 Effect of interfacial slip on the cross-stream migration of a drop in an unbounded Poiseuille flow. Phys. Rev. E 92 (2), 023002.CrossRefGoogle Scholar
Mandal, S., Bandopadhyay, A. & Chakraborty, S. 2016 The effect of uniform electric field on the cross-stream migration of a drop in plane Poiseuille flow. J. Fluid Mech. 809, 726774.CrossRefGoogle Scholar
Manikantan, H. & Squires, T. M. 2020 Surfactant dynamics: hidden variables controlling fluid flows. J. Fluid Mech. 892.CrossRefGoogle Scholar
Mukherjee, S. & Sarkar, K. 2013 Effects of matrix viscoelasticity on the lateral migration of a deformable drop in a wall-bounded shear. J. Fluid Mech. 727, 318345.CrossRefGoogle Scholar
Mukherjee, S. & Sarkar, K. 2014 Lateral migration of a viscoelastic drop in a Newtonian fluid in a shear flow near a wall. Phys. Fluids 26 (10), 103102.CrossRefGoogle Scholar
Pak, O. S., Feng, J. & Stone, H. A. 2014 Viscous Marangoni migration of a drop in a Poiseuille flow at low surface Péclet numbers. J. Fluid Mech. 753, 535552.CrossRefGoogle Scholar
Pamme, N. 2007 Continuous flow separations in microfluidic devices. Lab on a Chip 7 (12), 16441659.CrossRefGoogle ScholarPubMed
Panigrahi, D. P., Santra, S., Banuprasad, T. N., Das, S. & Chakraborty, S. 2018 Interfacial viscosity-induced suppression of lateral migration of a surfactant-laden droplet in a non-isothermal Poiseuille flow. arXiv:1812.05060.Google Scholar
Raffiee, A. H., Ardekani, A. M. & Dabiri, S. 2019 Numerical investigation of elasto-inertial particle focusing patterns in viscoelastic microfluidic devices. J. Non-Newtonian Fluid Mech. 272, 104166.CrossRefGoogle Scholar
Raffiee, A. H., Dabiri, S. & Ardekani, A. M. 2017 Deformation and buckling of microcapsules in a viscoelastic matrix. Phys. Rev. E 96 (3), 032603.CrossRefGoogle Scholar
Rubinow, S. I. & Keller, J. B. 1961 The transverse force on a spinning sphere moving in a viscous fluid. J. Fluid Mech. 11 (3), 447459.CrossRefGoogle Scholar
Saffman, P. G. T. 1965 The lift on a small sphere in a slow shear flow. J. Fluid Mech. 22 (2), 385400.CrossRefGoogle Scholar
Santra, S., Das, S., Das, S. S. & Chakraborty, S. 2018 Surfactant-induced retardation in lateral migration of droplets in a microfluidic confinement. Microfluid Nanofluid 22 (8), 88.CrossRefGoogle Scholar
Schwalbe, J. T., Phelan, F. R. Jr., Vlahovska, P. M. & Hudson, S. D. 2011 Interfacial effects on droplet dynamics in Poiseuille flow. Soft Matt. 7 (17), 77977804.CrossRefGoogle Scholar
Scriven, L. E. 1960 Dynamics of a fluid interface equation of motion for Newtonian surface fluids. Chem. Engng Sci. 12 (2), 98108.CrossRefGoogle Scholar
Segre, G. & Silberberg, A. 1961 Radial particle displacements in Poiseuille flow of suspensions. Nature 189 (4760), 209.CrossRefGoogle Scholar
Stan, C. A., Ellerbee, A. K., Guglielmini, L., Stone, H. A. & Whitesides, G. M. 2013 The magnitude of lift forces acting on drops and bubbles in liquids flowing inside microchannels. Lab on a Chip 13 (3), 365376.CrossRefGoogle ScholarPubMed
Stan, C. A., Guglielmini, L., Ellerbee, A. K., Caviezel, D., Stone, H. A. & Whitesides, G. M. 2011 Sheathless hydrodynamic positioning of buoyant drops and bubbles inside microchannels. Phys. Rev. E 84 (3), 036302.CrossRefGoogle ScholarPubMed
Stone, H. A., Stroock, A. D. & Ajdari, A. 2004 Engineering flows in small devices: microfluidics toward a lab-on-a-chip. Annu. Rev. Fluid Mech. 36, 381411.CrossRefGoogle Scholar
Vasseur, P. & Cox, R. G. 1976 The lateral migration of a spherical particle in two-dimensional shear flows. J. Fluid Mech. 78 (2), 385413.CrossRefGoogle Scholar
van Voorst Vader, F., Erkens, T. F. & Van den Tempel, M. 1964 Measurement of dilatational surface properties. Trans. Faraday Soc. 60, 11701177.CrossRefGoogle Scholar
Wang, S., Guo, T., Dabiri, S., Vlachos, P. P. & Ardekani, A. M. 2017 Effect of surfactant on bubble collisions on a free surface. Phys. Rev. Fluids 2 (4), 043601.CrossRefGoogle Scholar
Wohl, P. R. & Rubinow, S. I. 1974 The transverse force on a drop in an unbounded parabolic flow. J. Fluid Mech. 62 (1), 185207.CrossRefGoogle Scholar