Dynamic Measurements of Micro-Meter Particle Detachment on Glass Surfaces

This work presents a high resolution study of the condition under which a transient fluid flow causes spherical glass beads particles of 10–100 μm in size to detach from glass surfaces. The general approach is to conduct well-controlled experiments, to observe individual microparticle motion in short term resuspension, within a period up to 5s, and to focus on the basic detachment mechanisms of the resuspended particles to fully understand and quantify the behavior of particles immediately before liftoff. Particle tracking obtained from high-speed imaging of individual particle with 4000 frames/s, reveal three different types of motion: rolling/bouncing, immediate liftoff (where the particle showed immediate liftoff without any initial rolling/bouncing) and complex motion where particles travel with rolling/bouncing motion on the surface for a certain distance before liftoff. The longer it will take the particle to start its initial movement the more rapid is the liftoff once motion is initiated. The majority of particle trajectories from the glass substrate were parallel to the surface with complex motion, covering 25% of the total distance traveled in rolling/bouncing motion before liftoff. Additionally, Single layer detachment showed that the detachment percentage initially follow an exponentially increasing trend for a period of ∼ 1s, followed by a plateau phase for a period of 5s.