The Geometry-Induced Superhydrophobic Property of Carpet-like Zinc Films

Carpet-like zinc films with unique nanowires are fabricated by using a simple physical evaporation method. The definite morphologies of the films endow the superhydrophobic material with a contact angle of about 157.9, and by additional modification of CF3(CF2)(7)CH2CH2Si(OCH3)(3) the water adhesive force could be tuned from 58.3 mu N to 14.6 mu N. In order to analyze the controllable adhesion of superhydrophobic Zn films, we study the microstructure and chemical compositions of the films by x-ray diffraction SEM, TEM, HRTEM and EDAX. Furthermore, a model based on the balance of micro-surface energy is proposed to illustrate the relationship of the geometry and wettability properties of the films. The model provides new insights into how to design-oriented microchannels and micro-protuberance on material surfaces, which is of benefit for controlling their ability of caught-collection in air bubbles and water-pinning collection.