Dynamics of Colloids Confined in Microcylinders

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Abstract

We studied both global and local effects of cylindrical confinement on the diffusive behavior of hard sphere (HS) colloids. Using confocal scanning laser microscopy (CSLM) and particle tracking, we measured the mean squared displacement (MSD) of 1 micron sized silica particles in water–glycerol. This combination of fluid and setup allowed us to measure MSDs in a 4-dimensional parameter space, defined by the HS volume fraction (Φ: 0.05–0.39), cylinder radius (R: 2.5–20 micron), distance to the wall (z) and lagtime (τ: 0.03–60 s). MSDs for the entire cylinder confirm earlier findings that both narrowing the cylinder and populating it cause a slower dynamics. Additionally a decrease in R was found to cause a stronger ordering of the fluid. The effect of confinement on dynamics was further examined as a function of (z) location. For the largest cylinder (with minor curvature), we found that the strong decrease in MSD near the wall, becomes much less pronounced for higher Φ. Analyzing the radial (r) and azimuthal (θ) components, we found pronounced differences in the z-dependence that were ‘hidden’ in the total MSD. Near the wall, the r-MSD shows a much steeper z-dependence while at larger z, it shows a remarkable anti-correlation with the (peaked) density n(z). Also the dependence of the r-MSD on lagtime correlates with n(z): diffusive in between layers, but subdiffusive inside layers. These observations bring earlier findings together, while also shedding new light on the diffusive dynamics of concentrated colloids in narrow capillaries.
Original languageEnglish
Pages (from-to)1621-1630
JournalSoft matter
Volume12
Issue number5
DOIs
Publication statusPublished - 2016

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Colloids
colloids
Fluids
Silicon Dioxide
Volume fraction
Microscopic examination
laser microscopy
causes
fluids
Scanning
Lasers
curvature
silicon dioxide
radii
scanning

Keywords

  • METIS-313280
  • IR-99398

Cite this

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title = "Dynamics of Colloids Confined in Microcylinders",
abstract = "We studied both global and local effects of cylindrical confinement on the diffusive behavior of hard sphere (HS) colloids. Using confocal scanning laser microscopy (CSLM) and particle tracking, we measured the mean squared displacement (MSD) of 1 micron sized silica particles in water–glycerol. This combination of fluid and setup allowed us to measure MSDs in a 4-dimensional parameter space, defined by the HS volume fraction (Φ: 0.05–0.39), cylinder radius (R: 2.5–20 micron), distance to the wall (z) and lagtime (τ: 0.03–60 s). MSDs for the entire cylinder confirm earlier findings that both narrowing the cylinder and populating it cause a slower dynamics. Additionally a decrease in R was found to cause a stronger ordering of the fluid. The effect of confinement on dynamics was further examined as a function of (z) location. For the largest cylinder (with minor curvature), we found that the strong decrease in MSD near the wall, becomes much less pronounced for higher Φ. Analyzing the radial (r) and azimuthal (θ) components, we found pronounced differences in the z-dependence that were ‘hidden’ in the total MSD. Near the wall, the r-MSD shows a much steeper z-dependence while at larger z, it shows a remarkable anti-correlation with the (peaked) density n(z). Also the dependence of the r-MSD on lagtime correlates with n(z): diffusive in between layers, but subdiffusive inside layers. These observations bring earlier findings together, while also shedding new light on the diffusive dynamics of concentrated colloids in narrow capillaries.",
keywords = "METIS-313280, IR-99398",
author = "Somnath Ghosh and Dani{\"e}l Wijnperle and Mugele, {Friedrich Gunther} and Duits, {Michael H.G.}",
year = "2016",
doi = "10.1039/C5SM02581H",
language = "English",
volume = "12",
pages = "1621--1630",
journal = "Soft matter",
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}

Dynamics of Colloids Confined in Microcylinders. / Ghosh, Somnath; Wijnperle, Daniël; Mugele, Friedrich Gunther; Duits, Michael H.G.

In: Soft matter, Vol. 12, No. 5, 2016, p. 1621-1630.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Dynamics of Colloids Confined in Microcylinders

AU - Ghosh, Somnath

AU - Wijnperle, Daniël

AU - Mugele, Friedrich Gunther

AU - Duits, Michael H.G.

PY - 2016

Y1 - 2016

N2 - We studied both global and local effects of cylindrical confinement on the diffusive behavior of hard sphere (HS) colloids. Using confocal scanning laser microscopy (CSLM) and particle tracking, we measured the mean squared displacement (MSD) of 1 micron sized silica particles in water–glycerol. This combination of fluid and setup allowed us to measure MSDs in a 4-dimensional parameter space, defined by the HS volume fraction (Φ: 0.05–0.39), cylinder radius (R: 2.5–20 micron), distance to the wall (z) and lagtime (τ: 0.03–60 s). MSDs for the entire cylinder confirm earlier findings that both narrowing the cylinder and populating it cause a slower dynamics. Additionally a decrease in R was found to cause a stronger ordering of the fluid. The effect of confinement on dynamics was further examined as a function of (z) location. For the largest cylinder (with minor curvature), we found that the strong decrease in MSD near the wall, becomes much less pronounced for higher Φ. Analyzing the radial (r) and azimuthal (θ) components, we found pronounced differences in the z-dependence that were ‘hidden’ in the total MSD. Near the wall, the r-MSD shows a much steeper z-dependence while at larger z, it shows a remarkable anti-correlation with the (peaked) density n(z). Also the dependence of the r-MSD on lagtime correlates with n(z): diffusive in between layers, but subdiffusive inside layers. These observations bring earlier findings together, while also shedding new light on the diffusive dynamics of concentrated colloids in narrow capillaries.

AB - We studied both global and local effects of cylindrical confinement on the diffusive behavior of hard sphere (HS) colloids. Using confocal scanning laser microscopy (CSLM) and particle tracking, we measured the mean squared displacement (MSD) of 1 micron sized silica particles in water–glycerol. This combination of fluid and setup allowed us to measure MSDs in a 4-dimensional parameter space, defined by the HS volume fraction (Φ: 0.05–0.39), cylinder radius (R: 2.5–20 micron), distance to the wall (z) and lagtime (τ: 0.03–60 s). MSDs for the entire cylinder confirm earlier findings that both narrowing the cylinder and populating it cause a slower dynamics. Additionally a decrease in R was found to cause a stronger ordering of the fluid. The effect of confinement on dynamics was further examined as a function of (z) location. For the largest cylinder (with minor curvature), we found that the strong decrease in MSD near the wall, becomes much less pronounced for higher Φ. Analyzing the radial (r) and azimuthal (θ) components, we found pronounced differences in the z-dependence that were ‘hidden’ in the total MSD. Near the wall, the r-MSD shows a much steeper z-dependence while at larger z, it shows a remarkable anti-correlation with the (peaked) density n(z). Also the dependence of the r-MSD on lagtime correlates with n(z): diffusive in between layers, but subdiffusive inside layers. These observations bring earlier findings together, while also shedding new light on the diffusive dynamics of concentrated colloids in narrow capillaries.

KW - METIS-313280

KW - IR-99398

U2 - 10.1039/C5SM02581H

DO - 10.1039/C5SM02581H

M3 - Article

VL - 12

SP - 1621

EP - 1630

JO - Soft matter

JF - Soft matter

SN - 1744-683X

IS - 5

ER -