A Brownian dynamics simulation to predict morphology of nanoparticle deposits in the presence of interparticle interactions

Nanoparticles synthesized in high temperature reactors provide a viable method for depositing nanostructured coatings. The morphology of the deposit is an important factor in many applications and cannot be predicted by continuum models. Computer simulation of nanoparticle deposition is used to relate operational conditions to the resulting morphology. Brownian dynamic simulation of nanoparticle deposition, accounting for the interparticle van der Waals and Coulomb interactions, is carried out. Influence of van der Waals interactions, gas temperature, and thermophoretic and electrophoretic interactions on deposit morphology is investigated. Fractal dimension, packing density, and coordination number and contact angle distribution for the nanoparticle deposits are reported. Results show that by suitably controlling the external electrical field, deposits with fractal dimensions ranging from 2.2 to 2.8 and packing density varying from 2 to 13% can be obtained.