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Babu S, Rottereau M, Nicolai T, Gimel JC, Durand D. Flocculation and percolation in reversible cluster-cluster aggregation. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2006; 19:203-11. [PMID: 16505949 DOI: 10.1140/epje/e2006-00022-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Indexed: 05/06/2023]
Abstract
Off-lattice dynamic Monte-Carlo simulations were done of reversible cluster-cluster aggregation for spheres that form rigid bonds at contact. The equilibrium properties were found to be determined by the life time of encounters between two particles (te). te is a function not only of the probability to form or break a bond, but also of the elementary step size of the Brownian motion of the particles. In the flocculation regime the fractal dimension of the clusters is df=2.0 and the size distribution has a power law decay with exponent tau=1.5. At larger values of te transient gels are formed. Close to the percolation threshold the clusters have a fractal dimension df=2.7 and the power law exponent of the size distribution is tau=2.1. The transition between flocculation and percolation occurs at a characteristic weight average aggregation number that decreases with increasing volume fraction.
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Affiliation(s)
- S Babu
- Polymères Colloïdes Interfaces, UMR 6120 CNRS - Université du Maine, 72085, Le Mans Cedex 9, France
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Odriozola G, Schmitt A, Callejas-Fernández J, Martínez-García R, Leone R, Hidalgo-Álvarez R. Simulated Reversible Aggregation Processes for Different Interparticle Potentials: The Cluster Aging Phenomenon. J Phys Chem B 2003. [DOI: 10.1021/jp0262160] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- G. Odriozola
- Departamento de Química Física y Matemática, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay, and Departamento de Física Aplicada, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada, Spain
| | - A. Schmitt
- Departamento de Química Física y Matemática, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay, and Departamento de Física Aplicada, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada, Spain
| | - J. Callejas-Fernández
- Departamento de Química Física y Matemática, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay, and Departamento de Física Aplicada, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada, Spain
| | - R. Martínez-García
- Departamento de Química Física y Matemática, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay, and Departamento de Física Aplicada, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada, Spain
| | - R. Leone
- Departamento de Química Física y Matemática, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay, and Departamento de Física Aplicada, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada, Spain
| | - R. Hidalgo-Álvarez
- Departamento de Química Física y Matemática, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay, and Departamento de Física Aplicada, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada, Spain
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Grosskinsky S, Timme M, Naundorf B. Universal attractors of reversible aggregate-reorganization processes. PHYSICAL REVIEW LETTERS 2002; 88:245501. [PMID: 12059310 DOI: 10.1103/physrevlett.88.245501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2001] [Indexed: 05/23/2023]
Abstract
We analyze a general class of reversible aggregate-reorganization processes. These processes are shown to exhibit globally attracting equilibrium distributions, which are universal, i.e., identical for large classes of models. Furthermore, the analysis implies that, for studies of equilibrium properties of any such process, computationally expensive reorganization dynamics such as random walks can be replaced by more efficient yet simpler methods. As a particular application, our results explain the recent observation of the formation of similar fractal aggregates from different initial structures by diffusive reorganization [M. Filoche and B. Sapoval, Phys. Rev. Lett. 85, 5118 (2000)].
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Odriozola G, Schmitt A, Moncho-Jordá A, Callejas-Fernández J, Martínez-García R, Leone R, Hidalgo-Alvarez R. Constant bond breakup probability model for reversible aggregation processes. PHYSICAL REVIEW E 2002; 65:031405. [PMID: 11909055 DOI: 10.1103/physreve.65.031405] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2001] [Revised: 09/19/2001] [Indexed: 11/07/2022]
Abstract
Reversible aggregation processes were simulated for systems of freely diffusing sticky particles. Reversibility was introduced by allowing that all bonds in the system may break with a given probability per time interval. In order to describe the kinetics of such aggregation-fragmentation processes, a fragmentation kernel was developed and then used together with the Brownian aggregation kernel for solving the corresponding kinetic master equation. The deduced fragmentation kernel considers a single characteristic lifetime for all bonds and accounts for the cluster morphology by averaging over all possible configurations for clusters of a given size. It became evident that the simulated cluster-size distributions could be described only when an additional fragmentation effectiveness was considered. Doing so, the stochastic solutions were in good agreement with the simulated data.
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Affiliation(s)
- G Odriozola
- Departamento de Química Física y Matemática, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
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Filoche M, Sapoval B. Diffusion-reorganized aggregates: attractors in diffusion processes? PHYSICAL REVIEW LETTERS 2000; 85:5118-5121. [PMID: 11102200 DOI: 10.1103/physrevlett.85.5118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2000] [Indexed: 05/23/2023]
Abstract
A process based on particle evaporation, diffusion, and redeposition is applied iteratively to a two-dimensional object of arbitrary shape. The evolution spontaneously transforms the object morphology, converging to branched structures. Independently of initial geometry, the structures found after a long time present fractal geometry with a fractal dimension around 1.75. The final morphology, which constantly evolves in time, can be considered as the dynamic attractor of this evaporation-diffusion-redeposition operator. The ensemble of these fractal shapes can be considered to be the dynamical equilibrium geometry of a diffusion-controlled self-transformation process.
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Affiliation(s)
- M Filoche
- Laboratoire de Physique de la Matiere Condensee, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France
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Urbanc B, Cruz L, Buldyrev SV, Havlin S, Hyman BT, Stanley HE. Dynamic feedback in an aggregation-disaggregation model. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 60:2120-6. [PMID: 11970004 DOI: 10.1103/physreve.60.2120] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/1998] [Revised: 03/23/1999] [Indexed: 11/07/2022]
Abstract
We study an aggregation-disaggregation model which is relevant to biological processes such as the growth of senile plaques in Alzheimer disease. In this model, during the aggregation each deposited particle has a probability of producing a new particle in its vicinity, while during disaggregation the particles are anihilated randomly. The model is held in a dynamic equilibrium by a feedback mechanism which changes the disaggregation probability in proportion to the change in the total number of particles. We also include surface diffusion which influences the morphology of growing aggregates and colonies. A colony includes the descendents of a single particle. We investigate the statistical properties of the model in two dimensions. We find that unlike the colonies, individual aggregates are fractals with a fractal dimension of D(f)=1.92+/-0.06 in the absence of surface diffusion. We show that the surface diffusion changes the fractal dimension of aggregates: at a small aggregation-disaggregation rate, D(f) is independent of the strength of the surface diffusion, D(f)=1.73+/-0.03. At larger aggregation-disaggregation rates and different strengths of surface diffusion, aggregates with fractal dimensions between D(f)=1.73 and 1.92 form. The steady-state distribution of aggregate sizes is shown to be power law if the aggregation-disaggregation process dominates over the surface diffusion. In the limit of weak aggregation-disaggregation and strong surface diffusion the size distribution is log-normal.
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Affiliation(s)
- B Urbanc
- Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA
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Douglas JF. Swelling and growth of polymers, membranes, and sponges. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:2677-2689. [PMID: 9965381 DOI: 10.1103/physreve.54.2677] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Vanderzande C. Vesicles, the tricritical-0-state Potts model, and the collapse of branched polymers. PHYSICAL REVIEW LETTERS 1993; 70:3595-3598. [PMID: 10053914 DOI: 10.1103/physrevlett.70.3595] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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