Effect of particle surface corrugation on colloidal interactions

Abstract Hypothesis Production of corrugated particles generally introduces several morphological heterogeneities, such as surface roughness and local variations in the corrugation shape, which are known from model system studies to significantly alter the colloidal interaction energy. Thus, realistic particle morphologies need to be investigated and compared to simple model shapes to yield insights into how interactions are influenced by such morphological heterogeneities. Experiments We apply the surface element integration method to study the colloidal interactions of electron tomography-based, realistic, corrugated colloidal particles and their symmetric, concave polyhedral analogs. We differentiate local surface features to vertices, ridges and ridge networks. We apply molecular modelling to assess the surface access of these features. Findings Significant mixing of the interaction strength is found between different surface features. Larger and smaller energy barrier heights and secondary minimum depths are observed compared to the values of the corresponding smooth spheres with similar volume or surface area depending on the contacting surface feature. Analysis of surface area distributions suggests that the deviations originate from the increased effective contact distance as a result of surface roughness and other morphological heterogeneities. We also find that the surface access of nanoparticles is greatly impaired at the crevices between the surface corrugations.