Microscopic structure and elasticity of weakly aggregated colloidal gels

Citation:

Dinsmore, A. D. ; Prasad, V. ; Wong, I. Y. ; Weitz, D. A. Microscopic structure and elasticity of weakly aggregated colloidal gels. Physical Review Letters 2006, 96, 185502. Copy at http://www.tinyurl.com/y482dsc6
dinsmore2006.pdf856 KB

Abstract:

We directly probe the microscopic structure, connectivity, and elasticity of colloidal gels using confocal microscopy. We show that the gel is a random network of one-dimensional chains of particles. By measuring thermal fluctuations, we determine the effective spring constant between pairs of particles as a function of separation; this is in agreement with the theory for fractal chains. Long-range attractions between particles lead to freely rotating bonds, and the gel is stabilized by multiple connections among the chains. By contrast, short-range attractions lead to bonds that resist bending, with dramatically suppressed formation of loops of particles.

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Last updated on 04/22/2021