Compressive yield stress of depletion gels with variable interaction strength

Lattuada, E. (2019) Compressive yield stress of depletion gels with variable interaction strength. Il nuovo cimento C, 42 (5). pp. 1-10. ISSN 1826-9885

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Abstract

We studied the stationary sedimentation profiles of colloidal gels in which the arrested phase separation process is driven by depletion forces, obtained by compressing the samples by either natural or artificial gravity in the range between 6g and 2300g. We found that the rheological properties of these gels display a drastic change when the particle volume fraction φ exceeds a value φc which barely depends on the strength of the attractive forces. The compressive yield stress Π(φ), in fact, first grows as a power law of φ for φ φc and, then, displays a diverging behavior for larger values of the gel volume fraction, with an asymptotic value similar to the random close packing value for hard spheres. The evidence we collected suggests that φc essentially coincides with the colloid-rich liquid branch of the metastable coexistence line, rather than with an attractive glass line penetrating inside the coexistence region, for which lower φ values, also dependent on the strength of the interactions, are expected.

Item Type: Article
Subjects: 500 Scienze naturali e Matematica > 530 Fisica
Depositing User: Marina Spanti
Date Deposited: 29 Jan 2021 11:19
Last Modified: 29 Jan 2021 11:19
URI: http://eprints.bice.rm.cnr.it/id/eprint/20669

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