Modeling the self-assembly of nanoparticles into branched aggregates from a sessile nanofluid droplet

The drying of sessile nanofluid droplets on a surface can form various patterns and plays important role in micro and nano- manufacture technologies. In this paper, the kinetic Monte Carlo (KMC) approach based on the 2D Ising model is developed to simulate the drying process of a nanofluid droplet in a circular domain. In contrast to assuming a constant chemical potential in previous models, a chemical potential function dependent on time and the radius of the droplet is proposed. This model is used to investigate the formation of branched nanoparticle aggregates resulting from the drying of a nanofluid droplet. The predicted patterns from the drying droplet show a good agreement with the experiments. The distribution of particles and the shrinking of the contact line during the drying process, as well as the effects of the initial boundary chemical potential and the decrease rate of the chemical potential on the drying process have been investigated.