Repairable super-hydrophobic surface of silica fiber bulks modified with fluoroalkylmethoxysilane

The surface of porous bulks of silica fibers compacted by spark plasma sintering has been modified with fluoroalkylmethoxysilane, thereby obtaining super-hydrophobicity with a contact angle with water above 150°. Surface roughness and air trapped in pores of the compact surface are responsible for the super-hydrophobicity. More importantly, once the top layer of the compact wears, a fresh surface of the same fibrous structure re-appears, which again becomes super-hydrophobic after successive chemical modification. This demonstrates that the as-prepared material possesses repairable super-hydrophobicity. As this material can be machined, fine and complex channels of a super-hydrophobic inner surface are expected to be produced inside such a material.