Relaxation oscillations between Marangoni cells and double diffusive fingers in a reactive liquid–liquid system

Schwarzenberger, Karin; Eckert, Kerstin; Odenbach, Stefan

doi:10.1016/j.ces.2011.10.033

Cited by 20 publications

(15 citation statements)

References 48 publications

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“…Spatio-temporal convective patterns can become quite complex in the case of two immiscible solvents put in contact along a horizontal line, each of them containing a reactant. Upon transfer of one reactant from one phase to the other, a wealth of different convective chemohydrodynamic patterns can be observed in both the upper and lower layers ( Figure 11) (Eckert & Grahn (1999), Eckert et al (2004), Asad et al (2010), Schwarzenberger et al (2012)). The situation is then often complicated by the presence of Marangoni effects due to surface-tension gradients (Bratsun & De Wit (2004)) and modeling needs to account for reaction-diffusion-convection equations in both layers (Bratsun & De Wit (2011)).…”

Section: Effect Of A+b→c Reactions On Buoyancy-driven Convection In Imentioning

confidence: 99%

Chemo-Hydrodynamic Patterns and Instabilities

Wit

2020

Annu. Rev. Fluid Mech.

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By modifying a physical property of a solution like its density or viscosity, chemical reactions can modify and even trigger convective flows. These flows in turn affect the spatiotemporal distribution of the chemical species. A nontrivial coupling between reactions and flows then occurs. We present simple model systems of this chemo-hydrodynamic coupling. In particular, we illustrate the possibility of chemical reactions controlling or triggering viscous fingering, Rayleigh–Taylor, double-diffusive, and convective dissolution instabilities. We discuss laboratory experiments performed to study these phenomena and compare the experimental results to theoretical predictions. In each case we contrast the chemo-hydrodynamic patterns and instabilities with those that develop in nonreactive systems and unify the different dynamics in terms of the common features of the related spatial mobility profiles.

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Section: Effect Of A+b→c Reactions On Buoyancy-driven Convection In Imentioning

confidence: 99%

Chemo-Hydrodynamic Patterns and Instabilities

Wit

2020

Annu. Rev. Fluid Mech.

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“…The situation becomes even more complex if Marangoni effects are coupled to chemical reactions. In fact, oscillations can be observed for a variety of reactive systems [29][30][31][32][33][34][35]. Additional effects like chemical interaction of the solutes in the interfacial region, multi-component diffusion of educts and products or phase changes like precipitation however require a specific interpretation for each system.…”

Section: Introductionmentioning

confidence: 96%

Relaxation oscillations of solutal Marangoni convection at curved interfaces

Schwarzenberger

Aland

Domnick

et al. 2015

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…In this work, a recently discovered hydrodynamic effect is employed to create a novel, adaptive micromixer. For many years, the authors have been involved in the experimental and theoretical studies of the fundamental properties of soluto-capillary phenomena in different immiscible systems with [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ] and without chemical reactions [ 32 , 33 , 34 , 35 , 36 ]. Among the various effects studied by the authors, a prominent finding was that solutal Marangoni convection frequently is accompanied by intensive relaxation oscillations.…”

Section: Introductionmentioning

confidence: 99%

Adaptive Micromixer Based on the Solutocapillary Marangoni Effect in a Continuous-Flow Microreactor

et al. 2018

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Continuous-flow microreactors are an important development in chemical engineering technology, since pharmaceutical production needs flexibility in reconfiguring the synthesis system rather than large volumes of product yield. Microreactors of this type have a special vessel, in which the convective vortices are organized to mix the reagents to increase the product output. We propose a new type of micromixer based on the intensive relaxation oscillations induced by a fundamental effect discovered recently. The mechanism of these oscillations was found to be a coupling of the solutal Marangoni effect, buoyancy and diffusion. The phenomenon can be observed in the vicinity of an air–liquid (or liquid–liquid) interface with inhomogeneous concentration of a surface-active solute. Important features of the oscillations are demonstrated experimentally and numerically. The periodicity of the oscillations is a result of the repeated regeneration of the Marangoni driving force. This feature is used in our design of a micromixer with a single air bubble inside the reaction zone. We show that the micromixer does not consume external energy and adapts to the medium state due to feedback. It switches on automatically each time when a concentration inhomogeneity in the reaction zone occurs, and stops mixing when the solution becomes sufficiently uniform.

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Relaxation oscillations between Marangoni cells and double diffusive fingers in a reactive liquid–liquid system

Cited by 20 publications

References 48 publications

Chemo-Hydrodynamic Patterns and Instabilities

Chemo-Hydrodynamic Patterns and Instabilities

Relaxation oscillations of solutal Marangoni convection at curved interfaces

Adaptive Micromixer Based on the Solutocapillary Marangoni Effect in a Continuous-Flow Microreactor

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