Roselike microstructures formed by direct in situ hydrothermal synthesis: From superhydrophilicity to superhydrophobicity

We describe the fabrication of roselike microstructures by the direct in situ hydrothermal synthesis method. The as-prepared roselike microstructure film exhibits excellent superhydrophilic properties, absorbing a water droplet of 4 mu L in less than 40 ms. Moreover, after a further modification with a self-assembled monolayer of octyltrimethoxysilane, the film changes its wetting properties from superhydrophilicity to superhydrophobicity with a contact angle as high as 154 degrees and a tilt angle lower than 3 degrees.