A one-step hydrothermal process to fabricate superhydrophobic hydroxyapatite coatings and determination of their properties.

A novel one-step hydrothermal method has been developed to deposit a superhydrophobic hydroxyapatite coating on Mg-Gd-Nd-Zn-Zr alloy substrate from a solution containing stearic acid and calcium-phosphate compounds. The as-prepared coatings were mainly made up of hydroxyapatite and calcium stearate. When the volume ratio of ethanol and deionized water is 6:4, the hydroxyapatite coating had a maximum contact angle of 152.8° and a sliding angle of < 2°. Potentiodynamic polarization studies proved that the superhydrophobic hydroxyapatite coatings reduced the corrosion current density in Hank' Balanced Salt Solution (HBSS) by four orders of magnitude. Besides, the prepared coatings induced < 0.1% of hemolysis, satisfying the judging criterion for excellent blood compatibility. This rapid and environmentally friendly method could be of great value for the application of biomedical magnesium alloys. [ABSTRACT FROM AUTHOR]