Measurement of particle adhesion force and effective contact radius via centrifuge equipped with horizontal and vertical substrates

A centrifugal method was used to analyze and evaluate particle–surface interactions. Particles with count median diameters of 9.7, 14.5, and 32.8 μm were removed from horizontally and vertically mounted metal substrates. A point-mass model is conventionally used to analyze the forces exerted on particles during centrifugation. Conversely, in this study, a rigid-body model was employed considering the particle diameter and effective contact radius between a particle and substrate. As the moments of force exerted on the particles on the horizontal and vertical substrates were simultaneously formulated, the adhesion force and contact radius could be determined based on the particle diameter and angular velocities obtained at a given removal fraction. It was quantitatively demonstrated that as the particle diameter, relative humidity, and/or initial load increase and surface roughness decreases, the adhesion force increases. Furthermore, the contact radius increased as the particle diameter and/or surface roughness increased.