Triple line destabilization: Tuning film thickness through meniscus curvature

Particulate suspension coating of capillary tubes

“…One important consequence of this effect is that, even if in average it is possible to deposit a film of thickness and composition of the same order of magnitude as the initial composition of the suspension, the actual thickness and composition will both increase along the tube during the translation of the plug. Therefore, although this method can be interesting to deposit particles on the inner wall of a capillary tube, 40 it may be challenging to control very well the resulting coating and properties. We should emphasize that such an effect would also be observed at a constant flow rate, where u r would be constant, but where ϕ would follow a similar evolution.…”

“…12,14 If the fluid is partially wetting, i.e., its contact angle is θ > 0, the film dynamics is more complex as the contact line motion plays a role in determining the deposition patterns. 15,16 When solid particles are dispersed in a liquid, the usual interfacial dynamics and rheological approaches used to describe capillary flows can often fail when the lengthscale of the capillary object, here the liquid film, becomes comparable to the diameter of the particles. This peculiar dynamics of suspension has been considered in various configurations such as the formation of droplets, [17][18][19][20][21][22] the stability of jets, 23 the fragmentation of suspension sheets, 24 the motion of contact lines, 25 and during the formation of thin films.…”

“…, its contact angle is θ > 0, the film dynamics is more complex as the contact line motion plays a role in determining the deposition patterns. 15,16…”

“…Yet, such an approach could allow coating the inner wall of tubes, giving them some surface properties. 7,40 It would also lead to a better description of multiphase flows that involve particles and interfaces in porous media.…”