ON THE PROCESS OF BUBBLE GROWING AND DEPARTURE ON HYDROPHILIC, SUPERHYDROPHOBIC AND BIPHILIC SURFACES
This paper proposes an extensive investigation on single bubble dynamics under extreme wetting conditions,
to provide further insight on the development of custom made biphilic patterns (hydrophilic surfaces with
superhydrophobic regions) to improve pool boiling heat transfer. The heat transfer coefficient measured for
3 different biphilic patterns is first related with bubble dynamics. Then, detailed analysis of bubble growth
and detachment are discussed, taking the behavior of a bubble generated on a smooth hydrophilic surface as a
reference. The results evidence a strong relation between the heat transfer coefficient and the bubble interaction
mechanisms which, in turn depend on the area of the superhydrophobic regions and distance between them.
Different detachment and growth mechanisms are observed on the biphilic surfaces, controlled by the balance
between the adhesive and buoyancy forces which strongly affect the temporal evolution of the bubble shape.
Controlling the area of the superhydrophobic regions and gathering the information of the temporal description
of bubble growth and detachment provides a good control on bubble size and frequency, which, in turn, are
vital to control the interaction mechanisms.