Procédés et mécanique aux petites échelles PROMETHEE
Deformable micro-objects under hydrodynamic forcing
Microfluidics and Processes
Flow organization at small scales
Membrane separations
suite...
Processes and Small Scales Mechanics Team
Présentation
The PROMETHEE team develops marked competences in the field of continuum mechanics and process engineering, while combining experimental approaches with the development of theories and models. The originality of the studies carried out is declined according to several specificities:
Micro-nano scale of observation and analysis that evacuates the problems related to turbulence (Stokes regime) but requires to consider aspects at the boundaries of the discipline;
Predominant role of interfaces: interactions with solid walls at the nano scale (nano-tubes), fluid-structure interaction with fluid or polymerized membranes at the meso scale;
Connection with complex fluids, soft matter and biological systems.
On the theme of micro- and nano-fluidics, the objects of study, physico-chemical (drops, capsules,...) and biological (vesicles, red blood cells,...), also include the intensified processes of encapsulation and vectorization by microreactor, themes in full expansion. The team is also developing tools for characterizing the organization at small scales such as the development of numerical simulations to account for the segregation obtained within granular media and the development of chemical methods to characterize the effects of micromixing (mixing at the molecular scale). In addition to this, we are involved in the characterization and thermodynamic modeling of complex media.
The numerical tools developed and implemented are varied: boundary integral, finite elements, immersed boundary method, Lattice Boltzman method...
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v2⟩ Plus de détails...
We report on a systematic numerical exploration of the vesicle dynamics in a channel, which is a model of red blood cells in microcirculation. We find a spontaneous transition, called swirling, from straight motion with axisymmetric shape to a motion along a helix with a stationary deformed shape that rolls on itself and spins around the flow direction. We also report on a planar oscillatory motion of the mass center, called three-dimensional snaking for which the shape deforms periodically. Both emerge from supercritical pitchfork bifurcation with the same threshold. The universality of these oscillatory dynamics emerges from Hopf bifurcations with two order parameters. These two oscillatory dynamics are put in the context of vesicle shape and dynamics in the parameter space of reduced volume v, capillary number, and confinement. Phase diagrams are established for v = 0.95, v = 0.9, and v = 0.85 showing that oscillatory dynamics appears if the vesicle is sufficiently deflated. Stationary shapes (parachute/bullet/peanut, croissant, and slipper) are fixed points, while swirling and snaking are characterized by two limit cycles.
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v2⟩
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v1⟩ Plus de détails...
We report on a systematic numerical exploration of the vesicle dynamics in a channel, which is a model of red blood cells in microcirculation. We find a spontaneous transition, called swirling, from straight motion with axisymmetric shape to a motion along a helix with a stationary deformed shape that rolls on itself and spins around the flow direction. We also report on a planar oscillatory motion of the mass center, called three-dimensional snaking for which the shape deforms periodically. Both emerge from supercritical pitchfork bifurcation with the same threshold. The universality of these oscillatory dynamics emerges from Hopf bifurcations with two order parameters. These two oscillatory dynamics are put in the context of vesicle shape and dynamics in the parameter space of reduced volume v, capillary number, and confinement. Phase diagrams are established for v = 0.95, v = 0.9, and v = 0.85 showing that oscillatory dynamics appears if the vesicle is sufficiently deflated. Stationary shapes (parachute/bullet/peanut, croissant, and slipper) are fixed points, while swirling and snaking are characterized by two limit cycles.
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v1⟩
Revaz Chachanidze, Kaili Xie, Jinming Lyu, Marc Jaeger, Marc Leonetti. Breakups of Chitosan microcapsules in extensional flow. Journal of Colloid and Interface Science, 2023, 629, pp.445-454. ⟨10.1016/j.jcis.2022.08.169⟩. ⟨hal-03787637⟩ Plus de détails...
The controlled rupture of a core-shell capsule and the timely release of encapsulated materials are essential steps of the efficient design of such carriers. The mechanical and physico-chemical properties of their shells (or membranes) mainly govern the evolution of such systems under stress and notably the link between the dynamics of rupture and the mechanical properties. This issue is addressed considering weakly cohesive shells made by the interfacial complexation of Chitosan and PFacid in a planar extensional flow. Three regimes are observed, thanks to the two observational planes. Whatever the time of reaction in membrane assembly, there is no rupture in deformation as long as the hydrodynamic stress is below a critical value. At low times of complexation (weak shear elastic modulus), the rupture is reminiscent of the breakup of droplets: a dumbell or a waist. Fluorescent labelling of the membrane shows that this process is governed by continuous thinning of the membrane up to the destabilization. It is likely that the membrane shows a transition from a solid to liquid state. At longer times of complexation, the rupture has a feature of solid-like breakup (breakage) with a discontinuity of the membrane. The maximal internal constraint determined numerically marks the initial location of breakup as shown. The pattern becomes more complex as the elongation rate increases with several points of rupture. A phase diagram in the space parameters of the shear elastic modulus and the hydrodynamic stress is established.
Revaz Chachanidze, Kaili Xie, Jinming Lyu, Marc Jaeger, Marc Leonetti. Breakups of Chitosan microcapsules in extensional flow. Journal of Colloid and Interface Science, 2023, 629, pp.445-454. ⟨10.1016/j.jcis.2022.08.169⟩. ⟨hal-03787637⟩
Jiupeng Du, Nelson Ibaseta, Pierrette Guichardon. Characterization of polyurea microcapsules synthesized with an isocyanate of low toxicity and eco-friendly esters via microfluidics: Shape, shell thickness, morphology and encapsulation efficiency. Chemical Engineering Research and Design, 2022, 182, pp.256-272. ⟨10.1016/j.cherd.2022.03.026⟩. ⟨hal-04063865⟩ Plus de détails...
There are some studies on the synthesis of polyurea microcapsules. However, there is hardly a case where both green solvents and non-toxic isocyanates are used, especially in microfluidics. In this work, an environmentally friendly chemical system of interfacial polymerization (isocyanate: HDB-LV; solvent: octyl salicylate or dibutyl adipate) is tested for the first time to produce polyurea microcapsules. The size of microcapsules is calibrated at 78 μm by microfluidics to quantitatively analyze the relationships among shell thickness, encapsulation efficiency and isocyanate concentrations. The influences of solvent types and reactant concentrations on the shape, morphology and shell thickness of microcapsules are studied. Esters with low water miscibility and low amine concentrations (lower reaction rate) are crucial for the formation of spherical microcapsules. An ester with high water miscibility can diffuse into the continuous phase during encapsulation, which results in broken microcapsules. A high concentration of amine can probably cause cross-linking not only at the interface but also inside the droplet template, which leads to microcapsule deformation. A linear relationship is observed between the shell thickness of microcapsules and the isocyanate concentration. Overall, a high encapsulation efficiency (more than 90%) for octyl salicylate is achieved with polyurea microcapsules.
Jiupeng Du, Nelson Ibaseta, Pierrette Guichardon. Characterization of polyurea microcapsules synthesized with an isocyanate of low toxicity and eco-friendly esters via microfluidics: Shape, shell thickness, morphology and encapsulation efficiency. Chemical Engineering Research and Design, 2022, 182, pp.256-272. ⟨10.1016/j.cherd.2022.03.026⟩. ⟨hal-04063865⟩
Antoine Galko, Simon Gsell, Umberto d'Ortona, Laurent Morin, Julien Favier. Pulsated Herschel-Bulkley flows in two-dimensional channels: A model for mucus clearance devices. Physical Review Fluids, 2022, 7 (5), pp.053301. ⟨10.1103/PhysRevFluids.7.053301⟩. ⟨hal-03863329⟩ Plus de détails...
Mercredi 16 juin 2021
- De la vague déferlante au globule rouge / Soutenance HDR Paul Gang CHEN
Dr. Paul Gang CHEN
Date de soutenance : le mercredi 16 juin à 15h00 (visio - Zoom)
Résumé : au cours de cette soutenance, je présenterai mes différents travaux sur la modélisation et la simulation numérique d’écoulements interfaciaux : de la vague déferlante au globule rouge.
Jury :
M. Daniel Henry, LMFA, École Centrale de Lyon, Rapporteur
M. Grétar Tryggvason, Johns Hopkins University, Rapporteur
M. Stéphane Zaleski, d’Alembert, Sorbonne Université, Rapporteur
M. Richard Saurel, LMA, Aix-Marseille Université
M. Marc Jaeger, M2P2, École Centrale de Marseille, Tuteur
M. Marc Leonetti, LRP, Grenoble, Invité
Mardi 16 Mars
- Preparation of polyurea microcapsules calibrated in size and shell thickness by a microfluidic process for the absorption of ultraviolet / Soutenance de thèse Jiupeng DU
Doctorant : Jiupeng DU
Date de soutenance : le mardi 16 mars à 14h00 en VISIO
Abstract : This thesis aims to exploit the advantages of microfluidics for the production of polyurea microcapsules. Because of its ability to produce drops with a very narrow size distribution, microfluidic emulsification shows great interest as the first step for rapid interfacial polymerisation. Although the literature on the production of drops in microchannels is abundant, commonly used organic solvents are limited to certain toxic hydrocarbon oils or ketones, as these solvents are very hydrophobic and therefore easy to emulsify in water.
The first part of the work concentrates on the feasibility of emulsifying two less hydrophobic green solvents (dibutyl adipate and n-butyl acetate) in water and study the different flow regimes within a hydrophilic flow-focusing microchannel of glass. The results show that the wetting of the walls by dibutyl adipate can be modified by adding a surfactant (Tween 80). However, the formation of the drops being much faster than the transfer of the surfactant to the interface of the drop being formed, concentrations much higher than the critical micellar concentration are necessary to avoid wetting of the walls by the dispersed phase and thus the appearance of disordered flow regimes. The behavior of the n-butyl acetate/water system is similar, but the comparison of the flow maps for the two systems raises the question of the choice of dimensional numbers for representing the transition between the dripping and jetting regimes.
In the second part, the addition of an interfacial polymerization within the emulsion formed by microfluidics is studied in detail. We aim to fabricate polyurea microcapsules calibrated in size and shell thickness containing octyl salicylate (OS). These microcapsules are used to study, for the first time, the influence of the shell thickness of microcapsules on their absorption efficiency against ultraviolet (UV) light. The results show that an increase of the concentration of isocyanate (HDB-LV or hexamethylene diisocyanate biuret) in the organic phase increases the shell thickness of the microcapsules, their encapsulation efficiency and very moderately their average absorbance. The average absorbance of the microcapsules is inversely proportional to the size of the microcapsules (for the same mass of OS). A theoretical model is proposed to estimate the average absorbance as a function of the mass fraction of HDB-LV in the organic phase and of the size of microcapsules. Finally, the concentration of amine (ethylenediamine) has been optimized to ensure the spherical shape of the microcapsules.
Jury:
Marc LEONETTI (CNRS, LRP), Rapporteur
Nathalie LE SAUZE (Univ Toulouse III), Rapportrice
