title: Corrosion behavior and mechanical properties of bioactive sol-gel coatings on titanium implants.
abstract: Organic-inorganic hybrid coatings based on zirconia and poly (ε-caprolactone) (PCL) were prepared by means of sol-gel dip-coating technique and used to coat titanium grade 4 implants (Ti-4) in order to improve their wear and corrosion resistance. The coating chemical composition has been analysed by ATR-FTIR. The influence of the PCL amount has been investigated on the microstructure, mechanical properties of the coatings and their ability to inhibit the corrosion of titanium. SEM analysis has shown that all coatings have a nanostructured nature and that the films with high PCL content are crack-free. Mechanical properties of the coatings have been studied using scratch and nano-indentation tests. The results have shown that the Young's modulus of the coatings decreases in presence of large amounts of the organic phase, and that PCL content affects also the adhesion of the coatings to the underlying Ti-4 substrate. However, the presence of cracks on the PCL-free coatings affects severely the mechanical response of the samples at high loads. The electrochemical behavior and corrosion resistance of the coated and uncoated substrate has been investigated by polarization tests. The results have shown that both the coatings with or without PCL don't affect significantly the already excellent passivation properties of titanium.
authors.affiliation: Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa, Italy. Electronic address: michelina.catauro@unina2.it.
authors.forename: M
authors.initials: M
authors.lastname: Catauro
authors.affiliation: Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Bollino
authors.affiliation: Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Papale
authors.affiliation: Department of Engineering "Enzo Ferrari", University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Giovanardi
authors.affiliation: Department of Engineering "Enzo Ferrari", University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Veronesi
mesh_terms: D020099:Coated Materials, Biocompatible; D003343:Corrosion; D005782:Gels; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019736:Prostheses and Implants; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D005782:Gels; D014025:Titanium
keywords: Corrosion process; Organic–inorganic hybrid; Polarization tests; Scratch and nano-indentation tests; Sol-gel process