Tuning the rheological behavior of colloidal gels through competing interactions
(2020) In Physical Review Materials 4(4).- Abstract
We study colloidal gels formed by competing electrostatic repulsion and short-range attraction by means of extensive numerical simulations under external shear. We show that, upon varying the repulsion strength, the gel structure and its viscoelastic properties can be largely tuned. In particular, the gel fractal dimension can be either increased or decreased with respect to mechanical equilibrium conditions. Unexpectedly, gels with stronger repulsion, despite being mechanically stiffer, are found to be less viscous with respect to purely attractive ones. We provide a microscopic explanation of these findings in terms of the influence of an underlying phase separation. Our results allow for the design of colloidal gels with desired... (More)
We study colloidal gels formed by competing electrostatic repulsion and short-range attraction by means of extensive numerical simulations under external shear. We show that, upon varying the repulsion strength, the gel structure and its viscoelastic properties can be largely tuned. In particular, the gel fractal dimension can be either increased or decreased with respect to mechanical equilibrium conditions. Unexpectedly, gels with stronger repulsion, despite being mechanically stiffer, are found to be less viscous with respect to purely attractive ones. We provide a microscopic explanation of these findings in terms of the influence of an underlying phase separation. Our results allow for the design of colloidal gels with desired structure and viscoelastic response by means of additional electrostatic interactions, easily controllable in experiments.
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- author
- Ruiz-Franco, J. ; Camerin, F. LU ; Gnan, N. and Zaccarelli, E.
- publishing date
- 2020-04
- type
- Contribution to journal
- publication status
- published
- in
- Physical Review Materials
- volume
- 4
- issue
- 4
- article number
- 045406
- publisher
- American Physical Society
- external identifiers
-
- scopus:85084657941
- ISSN
- 2475-9953
- DOI
- 10.1103/PhysRevMaterials.4.045601
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2020 American Physical Society.
- id
- 60260b77-1190-48ea-892e-d4b3528a01eb
- date added to LUP
- 2024-02-22 14:13:14
- date last changed
- 2024-02-23 16:04:34
@article{60260b77-1190-48ea-892e-d4b3528a01eb, abstract = {{<p>We study colloidal gels formed by competing electrostatic repulsion and short-range attraction by means of extensive numerical simulations under external shear. We show that, upon varying the repulsion strength, the gel structure and its viscoelastic properties can be largely tuned. In particular, the gel fractal dimension can be either increased or decreased with respect to mechanical equilibrium conditions. Unexpectedly, gels with stronger repulsion, despite being mechanically stiffer, are found to be less viscous with respect to purely attractive ones. We provide a microscopic explanation of these findings in terms of the influence of an underlying phase separation. Our results allow for the design of colloidal gels with desired structure and viscoelastic response by means of additional electrostatic interactions, easily controllable in experiments.</p>}}, author = {{Ruiz-Franco, J. and Camerin, F. and Gnan, N. and Zaccarelli, E.}}, issn = {{2475-9953}}, language = {{eng}}, number = {{4}}, publisher = {{American Physical Society}}, series = {{Physical Review Materials}}, title = {{Tuning the rheological behavior of colloidal gels through competing interactions}}, url = {{http://dx.doi.org/10.1103/PhysRevMaterials.4.045601}}, doi = {{10.1103/PhysRevMaterials.4.045601}}, volume = {{4}}, year = {{2020}}, }