Simulation and Measurement of the Adhesion Moment of a Particle-Wall Contact on the Atomic Scale

If a particle in contact with a wall gets stressed by an external force and the contact breaks, the particle will start an evasive movement. In many cases, the evasive movement with the smallest force to overcome is rolling. The resistive force - or better, resistive moment - that holds the particle in place was observed. To do so, a computer-based simulation was developed to calculate this adhesion moment for two contact cases: a smooth spherical particle on a wall in a gaseous environment and another spherical particle with an also spherical roughness. These calculated values can now be compared to experimental data, since an apparatus to measure the adhesion moment was installed at an environmental scanning electron microscope.