Micrometer-sized spherulites as building blocks for lotus leaf-like superhydrophobic coatings

Abstract

Micropapillae covered by nanometer-sized wax crystals are essential building blocks of lotus leaf surface for repelling water and self-cleaning. It is generally time-consuming and complex to construct similar artificial micropapillae covered by nanometer-sized protuberances in the fabrication of superhydrophobic coatings without the aid of nanomaterials or special materials. We develop a cost-efficient strategy to simplify the fabrication process of lotus leaf-like superhydrophobic coatings by using micrometer-sized spherulites as building blocks. Well-controlled lotus leaf-like superhydrophobic coatings were prepared from hydrogenated castor oil spherulites through a one-step solution-immersion process. The result coatings have water contact angles over 150° and water shedding angles below 10°. It was demonstrated that micrometer-sized spherulites originated from common material could easily form lotus leaf-like superhydrophobic coatings on different materials through simple crystallization process.