Superamphiphobic particles: how small can we go?
Water and oil repellent coatings--so-called superamphiphobic coatings--greatly reduce the interaction between a liquid and a solid. So far, only flat or weakly curved superhydrophobic and superamphiphobic surfaces have been designed. This raises the question of whether highly curved structures or microspheres are feasible. Therefore, we coated microspheres with a superamphiphobic layer and measured the force between the spheres and a liquid. A qualitatively different dependence of the adhesion force on the applied load for superamphiphobic and smooth spheres is detected. Furthermore, we demonstrate both experimentally and theoretically that superamphiphobicity fails below a critical particle radius, depending on topological details and type of liquid. Therefore, this study sets a fundamental physical limit to the application of superamphiphobic layers for small objects with high curvature.
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Ming
M
Ye
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Xu
X
Deng
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Javed
J
Ally
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Periklis
P
Papadopoulos
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Frank
F
Schellenberger
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Doris
D
Vollmer
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Michael
M
Kappl
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
Hans-Jürgen
HJ
Butt