Stability of nano-hydroxyapatite thin coatings at liquid/solid interface

Abstract

The stability of nano-hydroxyapatite thin coatings immediately after deposition, sonication and prolong water exposure was monitored using the quartz crystal microbalance. Different morphological forms of nano-hydro xyapatite particles were obtained using three different synthesis routes. Electrophoretic deposition and spin coating techniques were used for the fabrication of nano-hydroxyapatite coatings on gold quartz crystal mi crobalance sensors. Synthesized nano-hydroxyapatite particles and coatings were characterized by spectroscopic techniques such as, Powder X-ray Diffraction (PXRD) and Fourier Transform Infrared (FTIR), and Scanning Electron Microscopy (SEM). All resulting thin coatings showed stability under ultrasonic treatment in aqueous medium, however the stability varied under subsequent prolong exposure to similar mediums. Comparative studies on these thin coatings indicated that the resulting coating morphology in the form of preferential crystal orientation, and the solution at interface are the key parameters that control the thin coating stability.