Dynamic simulation of flocculation: fractal particles in a polymer matrix

Principal investigator:
Co-investigator(s): James BUSFIELD
Flocculation model

In a variety of applications, micro or nanoparticles are used in a polymer matrix to modify the mechanical property of the particle-polymer mixture. Particles are used for instance in many complex fluids as thickeners to enhance viscosity and texture (e.g. in cosmetics), and to improve the mechanical performance of materials such as filled rubber and nanocomposites.

The structure of a colloidal dispersion, i.e. the physical arrangement of the particles, depends sensitively on the amount of shear used during processing, on the shearing time, on the particle size, on the particle structure, and on the surface chemistry of the particles. In this project, we will explore these parameters numerically, with the specific goal of understanding dispersion in filled rubber.

For the simulation, we are implementing a modified Brownian Dynamics simulations in which the polymers are treated as a continuum (we implicitly relying on scale separation between the polymers and the particles). We attempt to include in the simulation the best available inter-particle interaction models and incorporate the actual fractal structure of the particles. Our goal is to verify whether such a simulation approach can capture the main qualitative (and hopefully quantitative!) features observed in actual flocculation experiments.