Role of Particle Shape, Substrate Streaming Potential, and Ionic Strength in Kinetics and Spatial Distribution of Electrostatically Deposited Silver Nanoparticles

The electrostatic deposition of colloidal nanoparticles is a powerful way of constructing different types of composites, but its direct mechanism is not reliably established. In this work, we demonstrate correlations between the streaming potential of a polymeric substrate, ionic strength of a solution, and shape of silver nanoparticles on the one side and the deposition kinetics, optical properties, and 2D distribution of nanoparticles in the deposited layer on the other. We show that, unlike nanoplates, the quasi-spherical shape of silver nanoparticles and the low substrate streaming potential together with the low ionic strength favor the ordering of 2D nanoparticle's ordering. We also demonstrate the correlation between the real 2D distribution of nanoparticles and the distribution computed using the extended random sequential adsorption model and Monte Carlo simulation, highlighting the importance of electrostatic repulsion between nanoparticles with different effective exclusion radius and shape.