Reversible Trapping of Colloids in Microgrooved Channels via Diffusiophoresis under Steady-State Solute Gradients

Singh, Naval; Vladisavljević, Goran T.; Nadal, François; Cottin-Bizonne, Cécile; Pirat, Christophe; Bolognesi, Guido

doi:10.1103/physrevlett.125.248002

Cited by 30 publications

(40 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Diffusiophoresis has been studied as a mechanism for the motion of colloidal particles due to chemical gradients since its discovery by Derjaguin et al (1947). In recent microfluidic studies (Shin et al 2016;Ault et al 2017;Battat et al 2019;Gupta, Shim & Stone 2020b;Singh et al 2020;Wilson et al 2020;Alessio et al 2021), a dead-end pore configuration is used to set up a transient one-dimensional (1-D) diffusion of solutes; significant colloidal dispersion is observed, which the typical models are unable to capture. In addition to the dead-end pore geometry, experimental data in other microfluidic configurations have been reported in which colloidal dispersion can be observed but remains unexplained quantitatively (Abécassis et al 2008(Abécassis et al , 2009Palacci et al 2010Palacci et al , 2012McDermott et al 2012;Paustian et al 2015;Nery-Azevedo, Banerjee & Squires 2017;Shimokusu et al 2019).…”

Section: Introductionmentioning

confidence: 99%

“…The reports in the literature do acknowledge that diffusioosmosis along the channel walls induces flow of the bulk liquid, which causes colloidal dispersion (Keh & Ma 2005;Kar et al 2015;Shin et al 2016Shin et al , 2017Rasmussen, Pedersen & Marie 2020). However, only a few studies have combined the influences of diffusiophoresis and diffusioosmosis in order to investigate particle motion in more realistic settings (Shin et al 2017;Singh et al 2020;Williams et al 2020;Alessio et al 2021). In our previous article, we demonstrated that particle motion due to diffusiophoresis and a diffusioosmotic-slip-driven flow field that neglects the smallest dimension of the pore does predict a non-zero dispersion of colloids (Alessio et al 2021).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Diffusioosmosis-driven dispersion of colloids: a Taylor dispersion analysis with experimental validation

et al. 2022

View full text Add to dashboard Cite

Diffusiophoresis refers to the movement of colloidal particles in the presence of a concentration gradient of a solute and enables directed motion of colloidal particles in geometries that are inaccessible, such as dead-end pores, without imposing an external field. Previous experimental reports on dead-end pore geometries show that, even in the absence of mean flow, colloidal particles moving through diffusiophoresis exhibit significant dispersion. Existing models of diffusiophoresis are not able to predict the dispersion and thus the comparison between the experiments and the models is largely qualitative. To address these quantitative differences between the experiments and models, we derive an effective one-dimensional equation, similar to a Taylor dispersion analysis, that accounts for the dispersion created by diffusioosmotic flow from the channel sidewalls. We derive the effective dispersion coefficient and validate our results by comparing them with direct numerical simulations. We also compare our model with experiments and obtain quantitative agreement for a wide range of colloidal particle sizes. Our analysis reveals two important conclusions. First, in the absence of mean flow, dispersion is driven by the flow created by diffusioosmotic wall slip such that spreading can be reduced by decreasing the channel wall diffusioosmotic mobility. Second, the model can explain the spreading of colloids in a dead-end pore for a wide range of particle sizes. We note that, while the analysis presented here focuses on a dead-end pore geometry with no mean flow, our theoretical framework is general and can be adapted to other geometries and other background flows.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Diffusioosmosis-driven dispersion of colloids: a Taylor dispersion analysis with experimental validation

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Whether it is diffusiophoresis causing this will therefore need to be experimentally verified. Diffusiophoresis is typically investigated by setting up a gradient of salt and observing the motion of colloidal particles along this gradient, for example in dead-end microfluidic channels (Shin et al 2016;Singh et al 2020). This could be adapted with two colloidal particle sizes.…”

Section: Discussionmentioning

confidence: 99%

Stratification in drying films: a diffusion–diffusiophoresis model

Rees-Zimmerman

Routh

2021

J. Fluid Mech.

View full text Add to dashboard Cite

This research is motivated by the desire to control the solids distribution during the drying of a film containing particles of two different sizes. A variety of particle arrangements in dried films has been seen experimentally, including a thin layer of small particles at the top surface. However, it is not fully understood why this would occur. This work formulates and solves a colloidal hydrodynamics model for (i) diffusion alone and (ii) diffusion plus excluded volume diffusiophoresis, to determine their relative importance in affecting the particle arrangement. The methodology followed is to derive partial differential equations (PDEs) describing the motion of two components in a drying film. The diffusive fluxes are predicted by generalising the Stokes–Einstein diffusion coefficient, with the dispersion compressibility used to produce equations valid up until close packing. A further set of novel equations incorporating diffusiophoresis is derived. The diffusiophoretic mechanism investigated in this work is the small particles being excluded from a volume around the large particles. The resulting PDEs are scaled and solved numerically using a finite volume method. The model includes the chemical potentials of the particles, allowing for incorporation of any interaction term. The relative magnitudes of the fluxes of the differently sized particles are compared using scaling arguments and via numerical results. The diffusion results, without any inter-particle interactions, predict stratification of large particles to the top surface. Addition of excluded volume diffusiophoresis introduces a downwards flux on the large particles, that can result in small-on-top stratification, thus providing a potential explanation of the experimental observations.

show abstract

“…Alternative mechanisms have thus been explored to drive particle migration using nonequilibrium gradients, e.g., surface tension gradients (Marangoni) (14,15), diffusiophoresis (16), electrophoresis (17), and chemotaxis (18). Nonequilibrium fluxes have been imposed using gradients of various salts (19)(20)(21), surfactants (22,23), polymers (24), and enzyme substrates (25) or of field variables like temperature (26), pH (27,28), or dissolved gas (29). A variety of particle types have been driven in this way, including solid particles, droplets, or bubbles (30)(31)(32), enzymes (25), and cells (33).…”

Section: Introductionmentioning

confidence: 99%

A two-step strategy for delivering particles to targets hidden within microfabricated porous media

et al. 2021

View full text Add to dashboard Cite

The delivery of small particles into porous environments remains highly challenging because of the low permeability to the fluids that carry these colloids. Even more challenging is that the specific location of targets in the porous environment usually is not known and cannot be determined from the outside. Here, we demonstrate a two-step strategy to deliver suspended colloids to targets that are “hidden” within closed porous media. The first step serves to automatically convert any hidden targets into soluto-inertial “beacons,” capable of sustaining long-lived solute outfluxes. The second step introduces the deliverable objects, which are designed to autonomously migrate against the solute fluxes emitted by the targets, thereby following chemical trails that lead to the target. Experimental and theoretical demonstrations of the strategy lay out the design elements required for the solute and the deliverable objects, suggesting routes to delivering colloidal objects to hidden targets in various environments and technologies.

show abstract

Reversible Trapping of Colloids in Microgrooved Channels via Diffusiophoresis under Steady-State Solute Gradients

Cited by 30 publications

References 18 publications

Diffusioosmosis-driven dispersion of colloids: a Taylor dispersion analysis with experimental validation

Diffusioosmosis-driven dispersion of colloids: a Taylor dispersion analysis with experimental validation

Stratification in drying films: a diffusion–diffusiophoresis model

A two-step strategy for delivering particles to targets hidden within microfabricated porous media

Contact Info

Product

Resources

About