A Facile Method To Prepare Superhydrophobic Coatings by Calcium Carbonate

In this work, we have developed a facile and inexpensive method to fabricate a superhydrophobic surface with hierarchical nano- and microstructures. The superhydrophobic surface was prepared through spin coating of a mixture of nano- and microsized calcium carbonate (CaCO3) suspensions on a substrate, followed by modification of a low-surface-energy monolayer of stearic acid. The key parameters of the fabrication of suitable surface morphologies, including the content of CaCO3 powder and the percentage of nano- and microsized CaCO3 powder, were also investigated. Results showed that the optimum CaCO3 content was 40 wt % and the self-cleaning property of the film was achieved only by the addition of 2 wt % microsized CaCO3 powder and 38 wt % nanosized CaCO3 powder. After modification with a self-assembled monolayer of stearic acid, the as-prepared coating showed self-cleaning properties with a water contact angle as high as 152.8° and a sliding angle of 7.8°.