posted on 2020-03-31, 18:34authored byJacopo Bernardini, Uddalok Sen, Mohamad Jafari Gukeh, Pietro Asinari, Constantine M. Megaridis
The
interaction of rising gas bubbles with submerged air-repelling or
air-attracting surfaces is relevant to various technological applications
that rely on gas-microvolume handling or removal. This work demonstrates
how submerged metal meshes with super air-attracting/repelling properties
can be employed to manipulate microvolumes of air, rising buoyantly
in the form of bubbles in water. Superaerophobic meshes are observed
to selectively allow the passage of air bubbles depending on the mesh
pore size, the bubble volume-equivalent diameter, and the bubble impact
velocity on the mesh. On the other hand, superaerophilic meshes reduce
or amplify the volume captured from a train of incoming bubbles. Finally,
a spatial wettability pattern on the mesh is used to control the size
of the outgoing bubble, and an empirical relation is formulated to
predict the released gas volume. The study demonstrates how porous
materials with controlled wettability can be used to precisely modulate
and control the outcome of bubble/mesh interactions.