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Shape and rheology of droplets with viscous surface moduli

Published online by Cambridge University Press:  11 January 2019

Vivek Narsimhan*
Affiliation:
Purdue University, School of Chemical Engineering, 480 Stadium Mall Drive, West Lafayette, IN 47907, USA
*
Email address for correspondence: vnarsim@purdue.edu

Abstract

We develop perturbation theories to describe the flow dynamics of a droplet with a thin layer of insoluble surfactant whose mechanics are described by interfacial viscosity, i.e. a Boussinesq–Scriven constitutive law. The theories quantify droplet deformation in the limit of small capillary number, large viscosity ratio, or large shear Boussinesq number, to a sufficient level of approximation where one can extract information about nonlinear rheology and droplet breakup. In the first part of this manuscript, we quantify the Taylor deformation parameter and inclination angle in shear and extensional flows, developing expressions that resolve discrepancies between current analytical theories and boundary element simulations. Interestingly, the theories we develop appear to accurately describe the inclination angle of a clean droplet over a wider range of viscosity ratios and capillary numbers than previous works. In the second part of the manuscript, we calculate how interfacial viscosity alters the extra stress of a dilute suspension of droplets, in particular the shear stress, normal stress differences, shear thinning and extensional thickening. The normal stresses are intimately related to the lateral migration of droplets in wall-bound shear flow, and we explore the influence of interfacial viscosity on this phenomenon. We conclude by discussing how one can use these theories to describe droplet breakup, and how one can incorporate additional effects into the perturbation theories such as viscoelastic membranes and/or Marangoni flows.

Type
JFM Papers
Copyright
© 2019 Cambridge University Press 

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References

Abreu, D., Levant, M., Steinberg, V. & Seifert, U. 2014 Fluid vesicles in flow. Adv. Colloid Interface Sci. 208, 129141; special issue in honour of Wolfgang Helfrich.Google Scholar
Bagchi, P. & Kalluri, R. M. 2010 Rheology of a dilute suspension of liquid-filled elastic capsules. Phys. Rev. E 81, 056320.Google Scholar
Barthés-Biesel, D. 2016 Motion and deformation of elastic capsules and vesicles in flow. Annu. Rev. Fluid Mech. 48 (1), 2552.Google Scholar
Barthés-Biesel, D. & Acrivos, A. 1973 Deformation and burst of a liquid droplet freely suspended in a linear shear field. J. Fluid Mech. 61 (1), 122.Google Scholar
Barthés-Biesel, D. & Sgaier, H. 1985 Role of membrane viscosity in the orientation and deformation of a spherical capsule suspended in shear flow. J. Fluid Mech. 160, 119135.Google Scholar
Bentley, B. J. & Leal, L. G. 1986 An experimental investigation of drop deformation and breakup in steady, two-dimensional linear flows. J. Fluid Mech. 167, 241283.Google Scholar
Boussinesq, M. 1913 Sur l’existence d’une viscosité superficielle, dans la mince couche de transition séparant un liquide d’un autre fluide contigue. Ann. Chim. Phys. 29, 349357.Google Scholar
Brooks, C. F., Fuller, G. G., Frank, C. W. & Robertson, C. R. 1999 An interfacial stress rheometer to study rheological transitions in monolayers at the air–water interface. Langmuir 15 (7), 24502459.Google Scholar
Brown, F. L. H. 2011 Continuum simulations of biomembrane dynamics and the importance of hydrodynamic effects. Q. Rev. Biophys. 44 (4), 391432.Google Scholar
Cates, M. E. & Clegg, P. S. 2008 Bijels: a new class of soft materials. Soft Matt. 4, 21322138.Google Scholar
Chaffey, C. E. & Brenner, H. 1967 A second-order theory for shear deformation of drops. J. Colloid Interface Sci. 24 (2), 258269.Google Scholar
Choi, S. Q., Steltenkamp, S., Zasadzinski, J. A. & Squires, T. M. 2011 Active microrheology and simultaneous visualization of sheared phospholipid monolayers. Nat. Commun. 2, 312317.Google Scholar
Cicuta, P., Keller, S. L. & Veatch, S. L. 2007 Diffusion of liquid domains in lipid bilayer membranes. J. Phys. Chem. B 111 (13), 33283331.Google Scholar
Cox, R. G. 1969 The deformation of a drop in a general time-dependent fluid flow. J. Fluid Mech. 37 (3), 601623.Google Scholar
Dahl, J. B., Narsimhan, V., Gouveia, B., Kumar, S., Shaqfeh, E. S. G. & Muller, S. J. 2016 Experimental observation of the asymmetric instability of intermediate-reduced-volume vesicles in extensional flow. Soft Matt. 12, 37873796.Google Scholar
Danov, K. D. 2001 On the viscosity of dilute emulsions. J. Colloid Interface Sci. 235 (1), 144149.Google Scholar
Discher, B. M., Won, Y.-Y., Ege, D. S., Lee, J. C-M., Bates, F. S., Discher, D. E. & Hammer, D. A. 1999 Polymersomes: tough vesicles made from diblock copolymers. Science 284 (5417), 11431146.Google Scholar
Erk, K. A., Martin, J. D., Schwalbe, J. T., Phelan, F. R. & Hudson, S. D. 2012 Shear and dilational interfacial rheology of surfactant-stabilized droplets. J. Colloid Interface Sci. 377 (1), 442449.Google Scholar
Erni, P. 2011 Deformation modes of complex fluid interfaces. Soft Matt. 7, 75867600.Google Scholar
Erni, P., Fischer, P. & Windhab, E. J. 2005 Deformation of single emulsion drops covered with a viscoelastic adsorbed protein layer in simple shear flow. Appl. Phys. Lett. 87 (24), 244104.Google Scholar
Flumerfelt, R. W. 1980 Effects of dynamic interfacial properties on drop deformation and orientation in shear and extensional flow fields. J. Colloid Interface Sci. 76 (2), 330349.Google Scholar
Frankel, N. A. & Acrivos, A. 1970 The constitutive equation for a dilute emulsion. J. Fluid Mech. 44 (1), 6578.Google Scholar
Fuller, G. G. & Vermant, J. 2012 Complex fluid–fluid interfaces: rheology and structure. Annu. Rev. Chem. Biomol. Engng 3 (1), 519543.Google Scholar
Gambin, Y., Lopez-Esparza, R., Reffay, M., Sierecki, E., Gov, N. S., Genest, M., Hodges, R. S. & Urbach, W. 2006 Lateral mobility of proteins in liquid membranes revisited. Proc. Natl Acad. Sci. USA 103 (7), 20982102.Google Scholar
Georgieva, D., Schmitt, V., Leal-Calderon, F. & Langevin, D. 2009 On the possible role of surface elasticity in emulsion stability. Langmuir 25 (10), 55655573.Google Scholar
Gounley, J., Boedec, G., Jaeger, M. & Leonetti, M. 2016 Influence of surface viscosity on droplets in shear flow. J. Fluid Mech. 791, 464494.Google Scholar
Klingler, J. F. & McConnell, H. M. 1993 Brownian motion and fluid mechanics of lipid monolayer domains. J. Phys. Chem. 97 (22), 60966100.Google Scholar
Langevin, D. 2000 Influence of interfacial rheology on foam and emulsion properties. Adv. Colloid Interface Sci. 88 (1), 209222; Beijing Conference, May 1999.Google Scholar
Lee, J. S. & Feijen, J. 2012 Polymersomes for drug delivery: design, formation and characterization. J. Control. Release 161 (2), 473483; Drug Delivery Research in Europe.Google Scholar
Levan, M. D. 1981 Motion of a droplet with a Newtonian interface. J. Colloid Interface Sci. 83 (1), 1117.Google Scholar
de Loubens, C., Deschamps, J., Edwards-Levy, F. & Leonetti, M. 2016 Tank-treading of microcapsules in shear flow. J. Fluid Mech. 789, 750767.Google Scholar
Mandal, S. & Chakraborty, S. 2017 Influence of interfacial viscosity on the dielectrophoresis of drops. Phys. Fluids 29 (5), 052002.Google Scholar
Manor, O., Lavrenteva, O. & Nir, A. 2008 Effect of non-homogeneous surface viscosity on the Marangoni migration of a droplet in viscous fluid. J. Colloid Interface Sci. 321 (1), 142153.Google Scholar
Narsimhan, V. 2018 Letter: the effect of surface viscosity on the translational speed of droplets. Phys. Fluids 30 (8), 081703.Google Scholar
Narsimhan, V. & Shaqfeh, E. S. G. 2010 Lateral drift and concentration instability in a suspension of bubbles induced by Marangoni stresses at zero Reynolds number. Phys. Fluids 22 (10), 101702.Google Scholar
Narsimhan, V., Spann, A. P. & Shaqfeh, E. S. G. 2014 The mechanism of shape instability for a vesicle in extensional flow. J. Fluid Mech. 750, 144190.Google Scholar
Narsimhan, V., Spann, A. P. & Shaqfeh, E. S. G. 2015 Pearling, wrinkling, and buckling of vesicles in elongational flows. J. Fluid Mech. 777, 126.Google Scholar
Oldroyd, J. D. 1955 The effect of interfacial stabilizing films on the elastic and viscous properties of emulsions. Proc. R. Soc. Lond. A 232 (1191), 567577.Google Scholar
Phillips, W. J., Graves, R. W. & Flumerfelt, R. W. 1980 Experimental studies of drop dynamics in shear fields: role of dynamic interfacial effects. J. Colloid Interface Sci. 76 (2), 350370.Google Scholar
Pozrikidis, C. 1994 Effects of surface viscosity on the finite deformation of a liquid drop and the rheology of dilute emulsions in simple shearing flow. J. Non-Newtonian Fluid Mech. 51 (2), 161178.Google Scholar
Rallison, J. M. 1980 Note on the time-dependent deformation of a viscous drop which is almost spherical. J. Fluid Mech. 98 (3), 625633.Google Scholar
Saffman, P. G. & Delbrück, M. 1975 Brownian motion in biological membranes. Proc. Natl Acad. Sci. USA 72 (8), 31113113.Google Scholar
Schowalter, W. R., Chaffey, C. E. & Brenner, H. 1968 Rheological behavior of a dilute emulsion. J. Colloid Interface Sci. 26 (2), 152160.Google 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, 77977804.Google Scholar
Scriven, L. E. 1960 Dynamics of a fluid interface equation of motion for Newtonian surface fluids. Chem. Engng Sci. 12 (2), 98108.Google Scholar
Smart, J. R. & Leighton, D. T. Jr 1991 Measurement of the drift of a droplet due to the presence of a plane. Phys. Fluids A 3 (1), 2128.Google Scholar
Taylor, G. I. 1934 The formation of emulsions in definable fields of flow. Proc. R. Soc. Lond. A 146 (858), 501523.Google Scholar
Torza, S., Cox, R. G. & Mason, S. G. 1972 Particle motions in sheared suspensions xxvii. Transient and steady deformation and burst of liquid drops. J. Colloid Interface Sci. 38 (2), 395411.Google Scholar
Velikov, K. P. & Velev, O. D. 2014 Stabilization of Thin Films, Foams, Emulsions and Bifluid Gels with Surface–Active Solid Particles, chap. 9, pp. 277306. Wiley-Blackwell.Google Scholar
Vlahovska, P. M., Bławzdziewicz, J. & Loewenberg, M. 2009a Small-deformation theory for a surfactant-covered drop in linear flows. J. Fluid Mech. 624, 293337.Google Scholar
Vlahovska, P. M., Podgorski, T. & Misbah, C. 2009b Vesicles and red blood cells in flow: from individual dynamics to rheology. C. R. Phys. 10 (8), 775789; complex and biofluids.Google Scholar
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