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arXiv · 1607.08167

Effects of contact-line pinning on the adsorption of nonspherical colloids at liquid interfaces

Anna Wang·W. Benjamin Rogers·Vinothan N. Manoharan
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Abstract

The effects of contact-line pinning are well-known in macroscopic systems, but are only just beginning to be explored at the microscale in colloidal suspensions. We use digital holography to capture the fast three-dimensional dynamics of micrometer-sized ellipsoids breaching an oil-water interface. We find that the particle angle varies approximately linearly with the height, in contrast to results from simulations based on minimization of the interfacial energy. Using a simple model of the motion of the contact line, we show that the observed coupling between translational and rotational degrees of freedom is likely due to contact-line pinning. We conclude that the dynamics of colloidal particles adsorbing to a liquid interface are not determined by minimization of interfacial energy and viscous dissipation alone; contact-line pinning dictates both the timescale and pathway to equilibrium.

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Anna Wang, W. Benjamin Rogers, Vinothan N. Manoharan. 2017-08-10. Effects of contact-line pinning on the adsorption of nonspherical colloids at liquid interfaces. https://doi.org/10.1103/physrevlett.119.108004

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