Adsorption of multiple spherical particles onto sinusoidally corrugated substrates.

We utilize a Monte Carlo simulation scheme based on the bond fluctuation model to simulate settlement of adhesive particles onto sinusoidally corrugated substrates. The particles are composed of a hard inner core with either an effective potential shell or a "soft" adhesive shell made of flexible arms attached to the particle surface. These chains adhere via either the effective potential shell or the sticky chain ends to the surface via pairwise nonspecific interactions. This simulation model allows for multiple particles to settle onto each tested substrate to elucidate the behavior of the collective adhesive layer featuring multiparticle assembly. Particles move within a 3D lattice space and settle on the substrate due to attractive particle/substrate interactions. Once a single particle adheres to the substrate, a new particle is introduced into the lattice to begin a new settlement. Through this multiparticle settlement mode, we explore the interplay among the characteristics of the particles (i.e., size, interaction shell) and the substrates (i.e., wavelength and periodicity) as well as interparticle interactions. We report that the adhesion of particles with an effective interaction shell to the substrates is reduced dramatically when the particle size is smaller than the feature width of the periodic substrate. The settlement of particles with flexible hair on the sinusoidally corrugated substrates is more complex. Specifically, the presence of flexible polymeric hairs makes the particle settlement more likely to occur on nearly all substrates studied irrespective of the characteristics of the substrate.