Floating behavior of hydrophobic glass spheres.
When a hydrophobic solid sphere is floating on water or salt solutions with different concentrations, it is at equilibrium under the impact of gravity, buoyancy force, and curvature force, the component of surface tension in the vertical direction. We have changed the diameters of the spheres and the concentrations of the two selected salts, NaCl and NaNO(3), to study the floating behaviors of these spheres and the contributions of surface tension and buoyancy force to their floatation. Generally speaking, the surface tension plays a more important role than the buoyancy force when the gravity is small, but the buoyancy force plays an identical or a more important role when the spheres are big enough. The wettability of the spheres significantly influences the height below the contact perimeter especially in salt solutions. The theoretical calculation meniscus slope angles at the sphere three-phase contact line are in agreement with experimental results.
Liu
Xinjie
X
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
Wang
Xiaolong
X
Liang
Yongmin
Y
Zhou
Feng
F
D005898:Glass; D057927:Hydrophobic and Hydrophilic Interactions; D008863:Microspheres; D008956:Models, Chemical; D012996:Solutions; D013500:Surface Tension; D014867:Water; D017155:Wettability
D012996:Solutions; D014867:Water