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Active microrheology in corrugated channels: Comparison of thermal and colloidal baths
- Source :
- Journal of Colloid and Interface Science, Journal of colloid and interface science 608, 2694-2702 (2022). doi:10.1016/j.jcis.2021.10.193, Dipòsit Digital de la UB, Universidad de Barcelona
- Publication Year :
- 2021
-
Abstract
- Hypothesis: The dynamics of colloidal suspension confined within porous materials strongly differs from that in the bulk. In particular, within porous materials, the presence of boundaries with complex shapes entangles the longitudinal and transverse degrees of freedom inducing a coupling between the transport of the suspension and the density inhomogeneities induced by the walls. Method: Colloidal suspension confined within model porous media are characterized by means of active microrheology where a net force is applied on a single colloid (tracer particle) whose transport properties are then studied. The trajectories provided by active microrheology are exploited to determine the local transport coefficients. In order to asses the role of the colloid-colloid interactions we compare the case of a tracer embedded in a colloidal suspension to the case of a tracer suspended in an ideal bath. Finding: Our results show that the friction coefficient increases and the passage time distribution widens upon increasing the corrugation of the channel. These features are obtained for a tracer suspended in a (thermalized) colloidal bath as well as for the case of an ideal thermal bath. These results highlight the relevance of the confinement on the transport and show a mild dependence on the colloidal/thermal bath. Finally, we rationalize our numerical results with a semi-analytical model. Interestingly, the predictions of the model are quantitatively reliable for mild external forces, hence providing a reliable tool for predicting the transport across porous materials. (c) 2021 Elsevier Inc. All rights reserved.
- Subjects :
- Microrheology
Materials science
Entropy
active microrheology
Degrees of freedom (physics and chemistry)
FOS: Physical sciences
Materials porosos
Condensed Matter - Soft Condensed Matter
Suspension (chemistry)
Biomaterials
Colloid
Colloid and Surface Chemistry
TRACER
Thermal
Porous materials
Colloids
Col·loides
digestive, oral, and skin physiology
Fluid Dynamics (physics.flu-dyn)
Mechanics
Physics - Fluid Dynamics
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
Condensed Matter::Soft Condensed Matter
Entropia
ddc:540
Particle
Soft Condensed Matter (cond-mat.soft)
entropic barriers
Porous medium
porous materials
Subjects
Details
- ISSN :
- 10957103
- Volume :
- 608
- Issue :
- Pt 3
- Database :
- OpenAIRE
- Journal :
- Journal of colloid and interface science
- Accession number :
- edsair.doi.dedup.....52ddd5ce0cbc193e8dc2f273e4629369
- Full Text :
- https://doi.org/10.1016/j.jcis.2021.10.193