Tantalum oxide/carbon nanotubes composite coatings on titanium, and their functionalization with organophosphonic molecular films: A high quality scaffold for hydroxyapatite growth

► Sol-gel elaboration of thin composite films made of Ta2O5 and MWCNTs on Ti. ► Optimization of the sol composition (acid catalyst), hydrolysis and drying steps. ► Functionalization of the coatings with organophosphonic acid molecular films. ► Obtained deposits are free of defects, very homogeneous, and resistant to corrosion. ► Effects of inorganic and organic layers on in vitro HAp growth are highly beneficial.