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Forced motion of a probe particle near the colloidal glass transition

P. Habdas·D. Schaar·Andrew C. Levitt·Eric R. Weeks
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Abstract

We use confocal microscopy to study the motion of a magnetic bead in a dense colloidal suspension, near the colloidal glass transition volume fraction $ϕ_g$. For dense liquid-like samples near $ϕ_g$, below a threshold force the magnetic bead exhibits only localized caged motion. Above this force, the bead is pulled with a fluctuating velocity. The relationship between force and velocity becomes increasingly nonlinear as $ϕ_g$ is approached. The threshold force and nonlinear drag force vary strongly with the volume fraction, while the velocity fluctuations do not change near the transition.

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P. Habdas, D. Schaar, Andrew C. Levitt, Eric R. Weeks. 2004-05-19. Forced motion of a probe particle near the colloidal glass transition. https://doi.org/10.1209/epl%2Fi2004-10075-y

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