Colloidal detachment from solid surfaces: Phase diagrams to determine the detachment regime

[Display omitted] •Phase diagrams allow indicating particle detachment by rolling, sliding, or lifting.•The existence of asperities increases the critical velocity for particle detachment.•Determination of asperity distribution from gradual particle detachment.•Quantification of particles attached in the primary and secondary energy minima.•Particle mobilisation occurs in order of decreasing of their sizes. Particle detachment during colloidal-suspension transport in porous media occurs in chemical and environmental engineering. Breach of the attached particles mechanical equilibrium conditions yields their mobilisation by rolling, sliding, or lifting. We introduced a novel phase diagram indicating the detachment regime for given transport conditions. The phase diagram structure follows from the mechanical equilibrium conditions. Seven series of laboratory tests in visualisation cell with various parameters have been conducted. Placing the observed detachment parameters on phase diagrams shows that rolling is the dominant detachment regime. A gradual detachment of particles was explained by a probabilistic distribution of the particle and surface parameters, and a novel method for the probabilistic distribution determination is developed. For the laboratory tests performed, correlating the critical velocity for particle mobilisation with asperity size allowed obtaining the asperity distribution on the substrate. The obtained distributions were in agreement with reported values of surface roughness on glass coverslips.