Nanopin film is an experimental material in nanotechnology developed in 2005 with unusual superhydrophobic properties [1].
This happens because it is covered with nanoscale, topped-off pins or cones perpendicular to the surface.
The surface is regarded as a composite material with mostly air and a small fraction constituted by the tops of the cones.
When the contact angle of the cone material is sufficiently large, Cassie's law predicts large contact angle values for the composite.
A solution of CoCl2•6H2O or cobalt chloride hexahydrate is heated at 60 °C for 24 hours in a chemical bath deposition to form a brucite type cobalt(II) hydroxide layer with composition The top coating is provided by lauric acid in a separate step.