The deposition of nanoparticles onto a solid surface is an important operation in the assembly of nanoparticles to form new materials for a variety of technological applications. This project will carry out atomic scale simulations of the spreading of water droplets on both pure and chemically modified silicon surfaces when the droplets contain nanoparticles of gallium nitride. Simulations will be conducted for sessile drops and for drops that impact the silicon surface. Patterning of gallium nitride nanoparticles on the silicon surface will be examined. Understanding the forces that determine the spreading of the drop and the deposition of the nanoparticles is essential to design a bottom up approach to manufacturing new materials for optoelectronic applications. The project will also engage undergraduate and masters students in research projects that will make connections between the atomic scale simulations and larger scale descriptions of droplet and nanoparticle dynamics.
Simulations will be conducted to discover how wetting kinetics and capillary forces depend on the interactions between particle and solvent, between particle and solid surface, and between solvent and solid surface. Forces acting on suspended nanoparticles will be directly computed from simulations and correlated with drop morphology and the environment near a given particles, such as proximity to an advancing contact line or proximity to other particles. Additional simulations will explore effects of particle size and concentration on particle patterning and forces computed during wetting and spreading. Force data extracted from the simulations will help validate and optimize analytical descriptions of the driving forces in nano-suspension wetting. The project will provide new insights into non-equilibrium thermodynamics and its manifestations in nanoscale systems by connecting interaction affinity to suspension wetting kinetics and particle behavior.
