Interaction of deformable solid and hollow particles with rough surface morphology in colloidal systems.

HYPOTHESIS AND BACKGROUND

A majority of natural particles have deformable and rough surfaces. Past research indicated a lack of information for a numerical model to simulate the potential non-contact interaction between two deformable particles with uneven surfaces. The simulation of deformable particles is critical to better understanding the interaction of deformable particles in colloidal systems. We hypothesized that numerical models could simulate the deformation process of solid and hollow particles, and the constructed models could predict the impact of deformation on the interaction of rough-surfaced solid or hollow deformable particles.

NUMERICAL MODELING

This work modeled the deformable solid and hollow particles with rough surface morphologies following a fractal geometry theory. Their non-contact interaction was simulated following the three-stages deformation model. Also, the impacts of surface tension, particle size, and surface roughness on the interaction of the particles were investigated.

FINDINGS

It was observed that the total potential energy of deformable solid and hollow particles followed a similar pattern under different conditions. The difference in the energy profile between solid and hollow particles is that the hollow particles generate a deeper primary minimum, and the energy barrier disappears, indicating that the hollow particles have better attachment affinity. The results show that the increased particle size will strengthen the deformability of deformable solid and hollow particles and their potential interaction, and particle size will be the most influential parameter in affecting the deformability of particles. When the particle size increased from 10 nm to 1000 nm, the deformation region of solid particles was enlarged from 5 nm to 90 nm. Nevertheless, increased surface tension would weaken the deformability of deformable solid and hollow particles, which would significantly reduce particle aggregation. The increase in the fractal dimension would reduce solid and hollow particles' deformability but increase the potential interaction energy. The controversial results could be found by increasing fractal roughness, which would improve the deformability of particles and reduce the interaction energy. The results of this study could be applied for foreseeing the deformation and interaction of deformable particles with potential applications in suspension systems, such as biological cell suspensions.