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arXiv · 1106.2566

On measuring colloidal volume fractions

Wilson C. K. Poon·Eric R. Weeks·C. Patrick Royall
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Abstract

Hard-sphere colloids are popular as models for testing fundamental theories in condensed matter and statistical physics, from crystal nucleation to the glass transition. A single parameter, the volume fraction (phi), characterizes an ideal, monodisperse hard-sphere suspension. In comparing experiments with theories and simulation, researchers to date have paid little attention to likely uncertainties in experimentally-quoted phi values. We critically review the experimental measurement of phi in hard-sphere colloids, and show that while statistical uncertainties in comparing relative values of phi can be as low as 0.0001, systematic errors of 3-6% are probably unavoidable. The consequences of this are illustrated by way of a case study comparing literature data sets on hard-sphere viscosity and diffusion.

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Wilson C. K. Poon, Eric R. Weeks, C. Patrick Royall. 2011-06-13. On measuring colloidal volume fractions. https://doi.org/10.1039/c1sm06083j

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