Compressive consolidation of strongly aggregated particle gels

Abstract

The compressive yield stress of particle gels shows a highly nonlinear dependence on the packing fraction. We have studied continuous compression processes, and discussed the packing fraction dependence with the particle scale rearrangements. The 2D simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions that approached close packing. The compression acts to reduce the size of the characteristic structural entities (i.e. the correlation length of the structure). We observed three stages of compression: (I) elastic-dominant regime; (II) single-mode plastic regime, where the network strengths are determined by the typical length scale and the rolling mode; and (III) multi-mode plastic regime, where sliding mode and connection breaks are important. We also investigated the way of losing the fractal correlation under compression. It turns out that both fractal dimension $D_{\mathrm{f}}$ and correlation length $\xi$ start to change from the early stage of compression, which is different from the usual assumption in theoretical models.

Simulation movies, etc., are available at http://www-levich.engr.ccny.cuny.edu/~seto/sites/colloidal_aggregates.html

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Cited by in corpus (6)

• Stress localization, stiffening and yielding in a model colloidal gel
• Time dependence in large amplitude oscillatory shear: a rheo-ultrasonic study of fatigue dynamics in a colloidal gel
• How Surface Roughness Affects the Interparticle Interactions at a Liquid Interface
• Wall Adhesion and Constitutive Modelling of Strong Colloidal Gels
• Micro-mechanical insights into the stress transmission in strongly aggregating colloidal gel
• Decoupling Structure and Elasticity in Colloidal Gels Under Isotropic Compression