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Rheological inversion of the universal aging dynamics of hectorite clay suspensions. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2015.11.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Farage TFF, Reinhardt J, Brader JM. Normal-stress coefficients and rod climbing in colloidal dispersions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:042303. [PMID: 24229168 DOI: 10.1103/physreve.88.042303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/11/2013] [Indexed: 06/02/2023]
Abstract
We calculate tractable microscopic expressions for the low-shear normal-stress coefficients of colloidal dispersions. Although restricted to the low rate regime, the presented formulas are valid for all volume fractions below the glass transition and for any interaction potential. Numerical results are presented for a system of colloids interacting via a hard-core attractive Yukawa potential, for which we explore the interplay between attraction strength and volume fraction. We show that the normal-stress coefficients exhibit nontrivial features close to the critical point and at high volume fractions in the vicinity of the reentrant glass transition. Finally, we exploit our formulas to make predictions about rod-climbing effects in attractive colloidal dispersions.
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Affiliation(s)
- T F F Farage
- Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland
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Ramírez-González P, Medina-Noyola M. General nonequilibrium theory of colloid dynamics. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:061503. [PMID: 21230674 DOI: 10.1103/physreve.82.061503] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 10/27/2010] [Indexed: 05/30/2023]
Abstract
A nonequilibrium extension of Onsager's canonical theory of thermal fluctuations is employed to derive a self-consistent theory for the description of the statistical properties of the instantaneous local concentration profile n(r,t) of a colloidal liquid in terms of the coupled time-evolution equations of its mean value n(r,t) and of the covariance [Formula in text] of its fluctuations δn(r,t)=n(r,t)-n(r,t). These two coarse-grained equations involve a local mobility function b(r,t) which, in its turn, is written in terms of the memory function of the two-time correlation function [Formula in text]. For given effective interactions between colloidal particles and applied external fields, the resulting self-consistent theory is aimed at describing the evolution of a strongly correlated colloidal liquid from an initial state with arbitrary mean and covariance n(0)(r) and σ(0)(r,r') toward its equilibrium state characterized by the equilibrium local concentration profile n(eq)(r) and equilibrium covariance σ(eq)(r,r'). This theory also provides a general theoretical framework to describe irreversible processes associated with dynamic arrest transitions, such as aging, and the effects of spatial heterogeneities.
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Affiliation(s)
- Pedro Ramírez-González
- Instituto de Física Manuel Sandoval Vallarta, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, San Luis Potosí, 78000 San Luis Potosí, Mexico
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Yeomans-Reyna L, Chávez-Rojo MA, Ramírez-González PE, Juárez-Maldonado R, Chávez-Páez M, Medina-Noyola M. Dynamic arrest within the self-consistent generalized Langevin equation of colloid dynamics. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:041504. [PMID: 17994991 DOI: 10.1103/physreve.76.041504] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 07/26/2007] [Indexed: 05/25/2023]
Abstract
This paper presents a recently developed theory of colloid dynamics as an alternative approach to the description of phenomena of dynamic arrest in monodisperse colloidal systems. Such theory, referred to as the self-consistent generalized Langevin equation (SCGLE) theory, was devised to describe the tracer and collective diffusion properties of colloidal dispersions in the short- and intermediate-time regimes. Its self-consistent character, however, introduces a nonlinear dynamic feedback, leading to the prediction of dynamic arrest in these systems, similar to that exhibited by the well-established mode coupling theory of the ideal glass transition. The full numerical solution of this self-consistent theory provides in principle a route to the location of the fluid-glass transition in the space of macroscopic parameters of the system, given the interparticle forces (i.e., a nonequilibrium analog of the statistical-thermodynamic prediction of an equilibrium phase diagram). In this paper we focus on the derivation from the same self-consistent theory of the more straightforward route to the location of the fluid-glass transition boundary, consisting of the equation for the nonergodic parameters, whose nonzero values are the signature of the glass state. This allows us to decide if a system, at given macroscopic conditions, is in an ergodic or in a dynamically arrested state, given the microscopic interactions, which enter only through the static structure factor. We present a selection of results that illustrate the concrete application of our theory to model colloidal systems. This involves the comparison of the predictions of our theory with available experimental data for the nonergodic parameters of model dispersions with hard-sphere and with screened Coulomb interactions.
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Affiliation(s)
- L Yeomans-Reyna
- Departamento de Física, Universidad de Sonora, Boulevard Luis Encinas y Rosales, 83000, Hermosillo, Sonora, Mexico
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Lionberger RA, Russel WB. Microscopic Theories of the Rheology of Stable Colloidal Dispersions. ADVANCES IN CHEMICAL PHYSICS 2007. [DOI: 10.1002/9780470141700.ch3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Yeomans-Reyna L, Acuña-Campa H, Guevara-Rodríguez FDJ, Medina-Noyola M. Self-consistent theory of collective Brownian dynamics: theory versus simulation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 67:021108. [PMID: 12636654 DOI: 10.1103/physreve.67.021108] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2002] [Revised: 10/12/2002] [Indexed: 05/24/2023]
Abstract
A recently developed theory of collective diffusion in colloidal suspensions is tested regarding the quantitative accuracy of its description of the dynamics of monodisperse model colloidal systems without hydrodynamic interactions. The idea is to exhibit the isolated effects of the direct interactions, which constitute the main microscopic relaxation mechanism, in the absence of other effects, such as hydrodynamic interactions. Here we compare the numerical solution of the fully self-consistent theory with the results of Brownian dynamics simulation of the van Hove function G(r,t) and/or the intermediate scattering function F(k,t) of four simple model systems. Two of them are representative of short-ranged soft-core repulsive interactions [(sigma/r)(mu), with mu>>1], in two and in three dimensions. The other two involve long-ranged repulsive forces in two (dipolar, r(-3) potential) and in three (screened Coulomb, or repulsive Yukawa interactions) dimensions. We find that the theory, without any sort of adjustable parameters or rescaling prescriptions, provides an excellent approximate description of the collective dynamics of these model systems, particularly in the short- and intermediate-time regimes. We also compare our results with those of the single exponential approximation and with the competing mode-mode coupling theory.
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Affiliation(s)
- Laura Yeomans-Reyna
- Departamento de Física, Universidad de Sonora, Boulevard Luis Encinas y Rosales, 83000 Hermosillo, Sonora, Mexico
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Yeomans-Reyna L, Medina-Noyola M. Self-consistent generalized Langevin equation for colloid dynamics. PHYSICAL REVIEW E 2001; 64:066114. [PMID: 11736243 DOI: 10.1103/physreve.64.066114] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2001] [Indexed: 11/07/2022]
Abstract
We present a general self-consistent theory of colloid dynamics which, for a system without hydrodynamic interactions, allows us to calculate F(k,t), and its self-diffusion counterpart F(S)(k,t), given the effective interaction pair potential u(r) between colloidal particles, and the corresponding equilibrium static structural properties. This theory is build upon the exact results for F(k,t) and F(S)(k,t) in terms of a hierarchy of memory functions, derived from the application of the generalized Langevin equation formalism, plus the proposal of Vineyard-like connections between F(k,t) and F(S)(k,t) through their respective memory functions, and a closure relation between these memory functions and the time-dependent friction function Delta zeta(t). As an illustrative application, we present and analyze a selection of numerical results of this theory in the short- and intermediate-time regimes, as applied to a two-dimensional repulsive Yukawa Brownian fluid. For this system, we find that our theory accurately describes the dynamic properties contained in F(k,t) in a wide range of conditions, including strongly correlated systems, at the longest times available from our computer simulations.
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Affiliation(s)
- L Yeomans-Reyna
- Instituto de Física Manuel Sandoval Vallarta, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64 78000, San Luis Potosí, SLP, Mexico
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Kollmann M, Nägele G. Colloidal electrolyte friction and sedimentation: A mode-coupling approach. J Chem Phys 2000. [DOI: 10.1063/1.1312272] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tanaka H. Viscoelastic model of phase separation in colloidal suspensions and emulsions. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 59:6842-52. [PMID: 11969673 DOI: 10.1103/physreve.59.6842] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/1998] [Indexed: 04/18/2023]
Abstract
We propose a simple physical model of phase separation of colloidal suspensions and emulsions, which we call the "viscoelastic model." On the basis of this model, we consider two poorly understood phenomena: (i) phase separation accompanying the formation of a transient gel, and its collapse, and (ii) shear effects on composition fluctuations and phase separation. These phenomena can be explained by "asymmetric stress division" between the components of a mixture due to their size difference; the interaction network of particles can store elastic energy, while a fluid component cannot. The importance of the bulk stress stemming from an interaction network is discussed, using a concept of self-induced elastic constraint due to connectivity. We argue that there are common features to polymer solutions, colloidal suspensions, emulsions, and possibly protein solutions. They originate from dynamic asymmetry between the components and the resulting interaction network of the slower component of a mixture, which leads to the formation of a transient gel.
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Affiliation(s)
- H Tanaka
- Institute of Industrial Science, University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan
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Lionberger RA, Russel WB. Effectiveness of nonequilibrium closures for the many body forces in concentrated colloidal dispersions. J Chem Phys 1997. [DOI: 10.1063/1.473029] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Delsanti M, Chang J, Lesieur P, Cabane B. Dynamic properties of aqueous dispersions of nanometric particles near the fluid–solid transition. J Chem Phys 1996. [DOI: 10.1063/1.472523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Baur P, Nägele G, Klein R. Nonexponential relaxation of density fluctuations in charge-stabilized colloids. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:6224-6237. [PMID: 9964983 DOI: 10.1103/physreve.53.6224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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