(363f) Topological DLVO Interactions of Spiky Particles with a Planar Substrate

The study of the interactions of anisotropic colloids with substrates is of interest due to their widespread applications in drug delivery, energy, defense, etc. Spiky colloidal particles are commonly seen in nature; however, considerable experimental and theoretical evidence undermines its adhesion effectiveness. Because of anisotropy, the spikes reduce the contact surface as well as the DLVO interactions. In this study, the DLVO interactions of a spiky particle with a planar substrate are modeled as a function of particle position, orientation, size, and spiky shape. The spiky particle’s topography is modeled using a spherical core with uniform and normally distributed superellipsoid spikes over its surface.

We quantify the DVLO interactions of the spiky particle with a planar substrate using the surface element integration method with a high-resolution surface mesh. We validated the results using a particle with tiny spikes near the limit of a smooth spherical particle interacting with the planar surface. Results show decreasing interaction energy as a function of position as the spike length increases. On the other hand, the DLVO interaction energy is highly dependent on the relative particle orientation with respect to the wall. It shows a maximum variation in the orientational space near the region with more spikes in contact with the substrate. Furthermore, the same orientational interaction energy dependence is found with different superellipsoid spikes, which directly correlates with the topological spike distribution but not with its shape, which shows how the spiky particles enhance the particle interaction with planar substrates.