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Anisotropic viscoelastic phase separation in polydisperse hard rods leads to nonsticky gelation.

ABSTRACT: Spinodal demixing into two phases having very different viscosities leads to viscoelastic networks-i.e., gels-usually as a result of attractive particle interactions. Here, however, we demonstrate demixing in a colloidal system of polydisperse, rod-like clay particles that is driven by particle repulsions instead. One of the phases is a nematic liquid crystal with a highly anisotropic viscosity, allowing flow along the director, but suppressing it in other directions. This phase coexists with a dilute isotropic phase. Real-space analysis and molecular-dynamics simulations both reveal a long-lived network structure that is locally anisotropic, yet macroscopically isotropic. We show that our system exhibits the characteristics of colloidal gelation, leading to nonsticky gels.

SUBMITTER: Ferreiro-Cordova C

PROVIDER: S-EPMC7035602 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

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Anisotropic viscoelastic phase separation in polydisperse hard rods leads to nonsticky gelation.

Ferreiro-Córdova Claudia C Royall C Patrick CP van Duijneveldt Jeroen S JS

Proceedings of the National Academy of Sciences of the United States of America 20200131 7

Spinodal demixing into two phases having very different viscosities leads to viscoelastic networks-i.e., gels-usually as a result of attractive particle interactions. Here, however, we demonstrate demixing in a colloidal system of polydisperse, rod-like clay particles that is driven by particle repulsions instead. One of the phases is a nematic liquid crystal with a highly anisotropic viscosity, allowing flow along the director, but suppressing it in other directions. This phase coexists with a ...[more]

PMID: 32005711

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