Hydrophobic Coatings Composed by Cubic-Shaped CdO Nanoparticles Grown by a Novel and Simple Microwave Method

Cube-shaped cadmium oxide (CdO) nanoparticles were deposited by a novel low cost microwave evaporation technique. High purity cadmium (Cd) flakes were placed in a microwave susceptor inside a commercial microwave oven. Metallic Cd was evaporated in less than 2 minutes and it was oxidized due to ambient oxygen. The CdO nanoparticles were deposited on a glass substrate placed few centimeters above the susceptor. The surfaces with nanoparticles were treated with a solution containing ethanol and phenyltriethoxysilane (PTES), and the hydrophobic properties of the as-synthesized and post-PTES-treated surfaces were studied. Morphological and structural information of the as-synthesized nanoparticles were investigated via SEM and XRD analysis. Contact angles (θC) for the as-synthesized CdO surfaces were about 112°, whereas, for ethanol/PTES-treated CdO nanoparticles surfaces, contact angles were improved to about 158°. Thus, ethanol/PTES-treated CdO nanoparticles obtained by this simple procedure showed superhydrophobicity properties of potential use in micro fluidic devices and some other applications in the future.