Dynamical heterogeneity in a model for permanent gels: Different behavior of dynamical susceptibilities

2008/10/14 by T. Abete, A. de Candia, E. Del Gado +5
Materials Science · Mathematics · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cluster (spacecraft) #Dynamical heterogeneity #Function (biology) #Gaussian #Limit (mathematics) #Material Dynamics and Properties #Mathematical analysis #Mathematics #Measure (data warehouse) #Percolation (cognitive psychology) #Percolation threshold #Physics #Plateau (mathematics) #Quantum mechanics #Statistical physics #Theoretical and Computational Physics #Thermal diffusivity #Thermodynamics #cond-mat.soft #cond-mat.stat-mech

paper · pdf · doi:10.1103/physreve.78.041404

published as Phys. Rev. E, 78, 041404 (2008) · 11 pages, 14 figures

openalex publication_date 2008/10/14 · arxiv created 2008/11/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We present a systematic study of dynamical heterogeneity in a model for permanent gels upon approaching the gelation threshold. We find that the fluctuations of the self-intermediate scattering function are increasing functions of time, reaching a plateau whose value, at large length scales, coincides with the mean cluster size and diverges at the percolation threshold. Another measure of dynamical heterogeneities-i.e., the fluctuations of the self-overlap-displays instead a peak and decays to zero at long times. The peak, however, also scales as the mean cluster size. Arguments are given for this difference in the long-time behavior. We also find that the non-Gaussian parameter reaches a plateau in the long-time limit. The value of the plateau of the non-Gaussian parameter, which is connected to the fluctuations of diffusivity of clusters, increases with the volume fraction and remains finite at the percolation threshold.

Citations

• Role of Repulsive Forces in Determining the Equilibrium Structure of Simple Liquids
• Glassy correlations and microstructures in randomly cross-linked homopolymer blends
• Canonical dynamics: Equilibrium phase-space distributions
• Diverging length scale and upper critical dimension in the Mode-Coupling Theory of the glass transition
• Lengthscale dependence of dynamic four-point susceptibilities in glass formers
• A unified formulation of the constant temperature molecular dynamics methods
• Viscosity critical behaviour at the gel point in a 3d lattice model
• Correlations in the Motion of Atoms in Liquid Argon
• Nonlinear susceptibility in glassy systems: A probe for cooperative dynamical length scales
• Dynamical Heterogeneity Close to the Jamming Transition in a Sheared Granular Material
• Scaling Concepts in Polymer Physics
• Spatial correlations in the dynamics of glassforming liquids: Experimental determination of their temperature dependence
• Universal Nature of Particle Displacements close to Glass and Jamming Transitions
• Spontaneous and induced dynamic fluctuations in glass formers. I. General results and dependence on ensemble and dynamics