TY - JOUR AU - Bigaj, A. AU - Upadhyay, V. AU - Rongy, L. TI - Thermal effects on chemically induced Marangoni convection around A + B → C reaction fronts JF - JOURNAL OF CHEMICAL PHYSICS J2 - J CHEM PHYS VL - 160 PY - 2024 IS - 6 SN - 0021-9606 DO - 10.1063/5.0187785 UR - https://m2.mtmt.hu/api/publication/34779272 ID - 34779272 N1 - Export Date: 9 April 2024 CODEN: JCPSA Correspondence Address: Bigaj, A.; Nonlinear Physical Chemistry Unit, CP231, Belgium; email: adam.bigaj@ulb.be LA - English DB - MTMT ER - TY - JOUR AU - Gao, Yuan AU - Paul, Justine E. AU - Chen, Manxin AU - Seth, Aarav AU - Liu, Qibang AU - Hong, Liu AU - Chamorro, Leonardo P. AU - Ewoldt, Randy H. AU - Sottos, Nancy R. AU - Geubelle, Philippe H. TI - Fluid convection driven by surface tension during free-surface frontal polymerization JF - MECHANICS OF MATERIALS J2 - MECH MATER VL - 194 PY - 2024 PG - 12 SN - 0167-6636 DO - 10.1016/j.mechmat.2024.104987 UR - https://m2.mtmt.hu/api/publication/35331974 ID - 35331974 LA - English DB - MTMT ER - TY - JOUR AU - Gao, Y. AU - Paul, J. E. AU - Chen, M. AU - Hong, L. AU - Chamorro, L. P. AU - Sottos, N. R. AU - Geubelle, P. H. TI - Buoyancy-Induced Convection Driven by Frontal Polymerization JF - PHYSICAL REVIEW LETTERS J2 - PHYS REV LETT VL - 130 PY - 2023 IS - 2 PG - 6 SN - 0031-9007 DO - 10.1103/PhysRevLett.130.028101 UR - https://m2.mtmt.hu/api/publication/33851994 ID - 33851994 AB - In this Letter, we study the interaction between a self-sustaining exothermic reaction front propagating in a direction perpendicular to that of gravity and the buoyancy-driven convective flow during frontal polymerization (FP) of a low-viscosity monomer resin. As the polymerization front transforms the liquid monomer into the solid polymer, the large thermal gradients associated with the propagating front sustain a natural convection of the fluid ahead of the front. The fluid convection in turn affects the reaction-diffusion (RD) dynamics and the shape of the front. Detailed multiphysics numerical analyses and particle image velocimetry experiments reveal this coupling between natural convection and frontal polymerization. The frontal Rayleigh (Ra) number affects the magnitude of the velocity field and the inclination of the front. A higher Ra number drives instability during FP, leading to the observation of thermal-chemical patterns with tunable wavelengths and magnitudes. LA - English DB - MTMT ER - TY - JOUR AU - Rivadeneira, Rodrigo AU - Vasquez, Desiderio A. TI - Transitions between convective reaction fronts in a Poiseuille flow JF - MECCANICA J2 - MECCANICA VL - 58 PY - 2023 IS - 4 SP - 699 EP - 710 PG - 12 SN - 0025-6455 DO - 10.1007/s11012-023-01643-8 UR - https://m2.mtmt.hu/api/publication/33891373 ID - 33891373 AB - Density driven convection changes the speed and shape of autocatalytic reaction-diffusion fronts propagating in liquids. These fronts acquire different symmetries depending on domain size and density gradients. In vertical tubes, the front shape can change from flat to nonaxisymmetric, and then to axisymmetric for larger density gradients. Imposing a Poiseuille flow will affect the transition between the different types of fronts, depending on the strength and the direction of the flow, with the nonaxisymmetric state dissapearing for strong flows. In most circumstances, the speed of the front decreases for fronts propagating against the direction of the Poiseuille flow. However, in some cases an adverse Poiseuille flow increases the front speed. This phenomena takes place near a transition between different types of fronts. Tilting the tube significantly changes the front propagation, increasing to a maximum speed for angles away from the vertical direction. In this paper, we study the combined effects of convection and forced Poiseuille flow in inclined tubes, solving numerically the reaction-diffusion equations coupled to the Navier-Stokes equations. LA - English DB - MTMT ER - TY - JOUR AU - Tiani, R. AU - Rongy, L. TI - Marangoni-driven nonlinear dynamics of bimolecular frontal systems: a general classification for equal diffusion coefficients JF - PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A - MATHEMATICAL PHYSICAL & ENGINEERING SCIENCES J2 - PHILOS TRANS - R SOC A VL - 381 PY - 2023 IS - 2245 PG - 14 SN - 1364-503X DO - 10.1098/rsta.2022.0080 UR - https://m2.mtmt.hu/api/publication/33836824 ID - 33836824 N1 - Cited By :1 Export Date: 24 January 2024 Correspondence Address: Tiani, R.; Nonlinear Physical Chemistry Unit, Belgium; email: reda.tiani@ulb.be Correspondence Address: Rongy, L.; Nonlinear Physical Chemistry Unit, Belgium; email: laurence.rongy@ulb.be AB - When bimolecular fronts form in solutions, their dynamics is likely to be affected by chemically driven convection such as buoyancy- and Marangoni-driven flows. It is known that front dynamics in the presence of buoyancy-driven convection can be predicted solely on the basis of the one-dimensional reaction-diffusion concentration profiles but that those predictions fail for Marangoni-driven convection. With a two-dimensional reaction-diffusion-Marangoni convection model, we analyze here convective effects on the time scalings of the front properties, together with the influence of reaction reversibility and of the ratio of initial reactants' concentrations on the front dynamics. The effect of buoyancy forces is here neglected by assuming the reactive system to be in zero-gravity condition and/or the solution density to be spatially homogenous.This article is part of the theme issue 'New trends in pattern formation and nonlinear dynamics of extended systems'. LA - English DB - MTMT ER - TY - JOUR AU - Vailati, A. AU - Bataller, H. AU - Bou-Ali, M. M. AU - Carpineti, M. AU - Cerbino, R. AU - Croccolo, F. AU - Egelhaaf, S. U. AU - Giavazzi, F. AU - Giraudet, C. AU - Guevara-Carrion, G. AU - Horváth, Dezső AU - Koehler, W. AU - Mialdun, A. AU - Porter, J. AU - Schwarzenberger, K. AU - Shevtsova, V. AU - De Wit, A. TI - Diffusion in liquid mixtures JF - NPJ MICROGRAVITY J2 - NPJ MICROGRAVITY VL - 9 PY - 2023 IS - 1 PG - 8 SN - 2373-8065 DO - 10.1038/s41526-022-00246-z UR - https://m2.mtmt.hu/api/publication/33889920 ID - 33889920 AB - The understanding of transport and mixing in fluids in the presence and in the absence of external fields and reactions represents a challenging topic of strategic relevance for space exploration. Indeed, mixing and transport of components in a fluid are especially important during long-term space missions where fuels, food and other materials, needed for the sustainability of long space travels, must be processed under microgravity conditions. So far, the processes of transport and mixing have been investigated mainly at the macroscopic and microscopic scale. Their investigation at the mesoscopic scale is becoming increasingly important for the understanding of mass transfer in confined systems, such as porous media, biological systems and microfluidic systems. Microgravity conditions will provide the opportunity to analyze the effect of external fields and reactions on optimizing mixing and transport in the absence of the convective flows induced by buoyancy on Earth. This would be of great practical applicative relevance to handle complex fluids under microgravity conditions for the processing of materials in space. LA - English DB - MTMT ER - TY - JOUR AU - Bere, Katalin AU - Nez, Emilie AU - Balog, Edina AU - Janovák, László AU - Sebők, Dániel AU - Kukovecz, Ákos AU - Roux, Clément AU - Pimienta, Veronique AU - Schuszter, Gábor TI - Enhancing the yield of calcium carbonate precipitation by obstacles in laminar flow in a confined geometry JF - PHYSICAL CHEMISTRY CHEMICAL PHYSICS J2 - PHYS CHEM CHEM PHYS VL - 23 PY - 2021 IS - 29 SP - 15515 EP - 15521 PG - 7 SN - 1463-9076 DO - 10.1039/D1CP01334C UR - https://m2.mtmt.hu/api/publication/32154322 ID - 32154322 LA - English DB - MTMT ER - TY - JOUR AU - Li, Zhuoxuan AU - Yuan, Ling AU - Liu, Mengfei AU - Cheng, Zhenfang AU - Zheng, Juhua AU - Epstein, Irving R. AU - Gao, Qingyu TI - The Briggs–Rauscher Reaction: A Demonstration of Sequential Spatiotemporal Patterns JF - JOURNAL OF CHEMICAL EDUCATION J2 - J CHEM EDUC VL - 98 PY - 2021 IS - 2 SP - 665 EP - 668 PG - 4 SN - 0021-9584 DO - 10.1021/acs.jchemed.0c00892 UR - https://m2.mtmt.hu/api/publication/31921671 ID - 31921671 N1 - Funding Agency and Grant Number: National Natural Science Foundation of China [21773304]; Natural Science Foundation of Jiangsu Province [BK20171186, CHE-1856484]; U.S. National Science Foundation Funding text: This work was supported by Grant 21773304 from the National Natural Science Foundation of China, the Natural Science Foundation of Jiangsu Province (Grant BK20171186), and Grant CHE-1856484 from the U.S. National Science Foundation. The authors would like to thank Rui Teng for their help with video processing. LA - English DB - MTMT ER - TY - JOUR AU - Bába, Péter AU - Tóth, Ágota AU - Horváth, Dezső TI - Surface-Tension-Driven Dynamic Contact Line in Microgravity JF - LANGMUIR J2 - LANGMUIR VL - 35 PY - 2019 IS - 2 SP - 406 EP - 412 PG - 7 SN - 0743-7463 DO - 10.1021/acs.langmuir.8b03592 UR - https://m2.mtmt.hu/api/publication/30443568 ID - 30443568 AB - We study the effect of Marangoni flow on a dynamic contact line formed by a propagating reaction front and a liquid-air interface. The self-sustained iodate-arsenous acid reaction maintains the production of the weakly surface active iodine leading to an unbalanced surface force along the tip of the reaction front. The experiments, performed in microgravity to exclude the contribution of buoyancy, reveal that the fluid flow generated by the surface tension gradient is localized to the contact line. The penetration depth of the surface stress is measured as 1-2 mm; therefore, with greater fluid height the liquid advancement on the upper surface does not lead to enhanced mixing in the bulk. Because the propagation velocity of the reactive interface remains at that of reaction-diffusion, the leading edge consists of two straight lines; a tilted segment connects the contact line on the surface with the vertical segment on bottom. Modeling calculations of the reaction-diffusion-advection system in three dimensions reconstruct the experimental observations and along with the experiments validate a model based on geometric spreading. According to the calculated flow field, the direction of significant fluid flow follows the concentration gradients and hence coincides with the propagation of the reaction front, allowing only negligible transverse flow in the upper fluid layer. LA - English DB - MTMT ER - TY - JOUR AU - Llamoza, Johan AU - Vasquez, Desiderio A. TI - Structures and Instabilities in Reaction Fronts Separating Fluids of Different Densities JF - MATHEMATICAL AND COMPUTATIONAL APPLICATIONS J2 - MATH COMPUT APPL VL - 24 PY - 2019 IS - 2 PG - 16 SN - 1300-686X DO - 10.3390/mca24020051 UR - https://m2.mtmt.hu/api/publication/30962590 ID - 30962590 AB - Density gradients across reaction fronts propagating vertically can lead to Rayleigh-Taylor instabilities. Reaction fronts can also become unstable due to diffusive instabilities, regardless the presence of a mass density gradient. In this paper, we study the interaction between density driven convection and fronts with diffusive instabilities. We focus in fluids confined in Hele-Shaw cells or porous media, with the hydrodynamics modeled by Brinkman's equation. The time evolution of the front is described with a Kuramoto-Sivashinsky (KS) equation coupled to the fluid velocity. A linear stability analysis shows a transition to convection that depends on the density differences between reacted and unreacted fluids. A stabilizing density gradient can surpress the effects of diffusive instabilities. The two-dimensional numerical solutions of the nonlinear equations show an increase of speed due to convection. Brinkman's equation lead to the same results as Darcy's laws for narrow gap Hele-Shaw cells. For large gaps, modeling the hydrodynamics using Stokes' flow lead to the same results. LA - English DB - MTMT ER - TY - JOUR AU - Almarcha, C. AU - Radisson, B. AU - Al Sarraf, E. AU - Villermaux, E. AU - Denet, B. AU - Quinard, J. TI - Interface dynamics, pole trajectories, and cell size statistics JF - PHYSICAL REVIEW E: COVERING STATISTICAL NONLINEAR BIOLOGICAL AND SOFT MATTER PHYSICS (2016-) J2 - PHYSICAL REVIEW E VL - 98 PY - 2018 IS - 3 PG - 5 SN - 2470-0045 DO - 10.1103/PhysRevE.98.030202 UR - https://m2.mtmt.hu/api/publication/30443571 ID - 30443571 AB - We demonstrate the possibility to reproduce the experimental evolution of an interface, here a flame front, through the trajectory of a few poles whose position in the complex plane expresses the interface shape. These poles are analytical solutions of the Sivashinsky equation and they evolve according to an ordinary differential equation. The direct comparison with experimental flame fronts propagating in a quasi-two-dimensional configuration is made at the nonlinear but deterministic stages of the front dynamics, reproducing a cell creation and fusion process. At later times, when the front is sensitive to noise as in the Kardar-Parisi-Zhang equation, we demonstrate that the cell size distribution is still ruled by the pole attractive nature. LA - English DB - MTMT ER - TY - JOUR AU - Inomoto, Osamu AU - Hauser, Marcus J. B. AU - Kobayashi, Ryo AU - Mueller, Stefan C. TI - Acceleration of chemical reaction fronts II. Gas-phase-diffusion limited frontal dynamics JF - EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS J2 - EUR PHYS J-SPEC TOP VL - 227 PY - 2018 IS - 5-6 SP - 509 EP - 520 PG - 12 SN - 1951-6355 DO - 10.1140/epjst/e2018-00075-y UR - https://m2.mtmt.hu/api/publication/30443569 ID - 30443569 AB - The propagation of reaction-diffusion fronts in an open liquid solution layer is critically affected by mass transfer between the liquid solution and the adjacent gas phase. This is the case in the iodate-arsenous acid (IAA) reaction when run under stoichiometric excess of iodate. Here, iodine is the reaction product, which has a low solubility in the liquid phase, hence, excess iodine rapidly evaporates. In the gas phase, it diffuses and overtakes the reaction front propagating in the liquid medium because its diffusion coefficient in the gas phase is considerably larger than that in aqueous solution. Evaporated iodine is re-dissolved into the reaction medium ahead of the reaction front. Since iodine is the autocatalytic species of the IAA reaction, this additional gas-phase transport may lead to an acceleration of the propagating reaction front. LA - English DB - MTMT ER - TY - JOUR AU - Inomoto, Osamu AU - Mueller, Stefan C. AU - Kobayashi, Ryo AU - Hauser, Marcus J. B. TI - Acceleration of chemical reaction fronts I. Surface tension-driven convection JF - EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS J2 - EUR PHYS J-SPEC TOP VL - 227 PY - 2018 IS - 5-6 SP - 493 EP - 507 PG - 15 SN - 1951-6355 DO - 10.1140/epjst/e2018-00074-6 UR - https://m2.mtmt.hu/api/publication/30443570 ID - 30443570 AB - Chemical fronts and waves travelling in reaction-diffusion systems frequently induce hydrodynamic flow. This adds an additional transport process to the mechanism of spatio-temporal structure formation and can lead to an acceleration of the chemical (reaction) front. We report on the acceleration of travelling chemical fronts elicited by convection, as caused by the Marangoni effect in the monostable iodate-arsenous acid reaction in a thin liquid film. At a stoichiometric excess of iodate over arsenous acid, the reaction produces a large amount of iodine, which is surface-active. At the reaction front, iodine is transferred from the bulk to the surface inducing spatio-temporal gradients of surface tension that lead to capillary flows. These flows, in turn, promote further iodine adsorption at the surface through hydrodynamic mixing effects. As a consequence, an acceleration of the chemical fronts is observed, even if the concentration difference across the front is constant. After the transient acceleration of the reaction front, it settles at a constant propagation velocity, which is assumed to be regulated by a balance in the mass transfer between the bulk and the surface. LA - English DB - MTMT ER -