Viscoelasticity near the gel-point: a molecular dynamics study

Abstract

We report on extensive molecular dynamics simulations on systems of soft spheres of functionality f, i.e. particles that are capable of bonding irreversibly with a maximum of f other particles. These bonds are randomly distributed throughout the system and imposed with probability p. At a critical concentration of bonds, p_c approximately equal to 0.2488 for f=6, a gel is formed and the shear viscosity ηdiverges according to η~ (p_c-p)^{-s}. We find s is approximately 0.7 in agreement with some experiments and with a recent theoretical prediction based on Rouse dynamics of phantom chains. The diffusion constant decreases as the gel point is approached but does not display a well-defined power law.

4 pages, 4 figures

References in corpus (1)

• Shear viscosity of a crosslinked polymer melt

Cited by in corpus (9)

• Gel to glass transition in simulation of a valence-limited colloidal system
• Effect of bond lifetime on the dynamics of a short-range attractive colloidal system
• The rigidity transition in polymer melts with van der Waals interactions
• Critical behaviour of the Rouse model for gelling polymers
• Anomalous stress relaxation in random macromolecular networks
• Normal stresses at the gelation transition
• A model for gelation with explicit solvent effects: Structure and dynamics
• Dynamics of gelling liquids: a short survey
• Variational bounds for the shear viscosity of gelling melts