resumo
Surgical grade stainless steel (316L SS) is a widely used implant material in orthopedic surgeries. However, the release of metallic ions evidenced from the 316L SS implants in vivo conditions is a big challenge. In order to minimize the release of metallic ions, coating the 316L SS implant with a biocompatible material like hydroxyapatite [HAP, Ca-10(PO4)(6)(OH)(2)] is one of the suitable methods. In this paper, the hydroxyapatite coating on borate passivated through poly-ortho-phenylenediamine (PoPD)-coated 316L SS by a dip coating method has been reported. The coatings were characterized by electrochemical techniques such as potentiodynamic polarization, electrochemical impedance spectroscopy, and cyclic voltammetry. Surface characterization studies of the coatings such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were also carried out. The leach out characteristics of the coatings was determined at the impressed potential. The mechanical property of the coatings was evaluated by Vicker's microhardness test. The Cr-rich passive film formed underneath the PoPD layer showed a higher protective efficiency. The ability to form apatite on the post-passivated PoPD-coated 316L SS specimen was examined by immersing it in the simulated body fluid. The enhanced corrosion resistivity of the HAP coating on the post-passivated PoPD-coated 316L SS was due to an effective barrier of PoPD followed by the passive film underneath the PoPD.
palavras-chave
IN-VIVO; PHENYLENEDIAMINE ISOMERS; BIOMEDICAL APPLICATIONS; CORROSION-RESISTANCE; CONDUCTIVE POLYMER; SURFACE TREATMENTS; OXYGEN DEPENDENCE; SOL-GEL; PT-IR; 316L
categoria
Electrochemistry
autores
Gopi, D; Indira, J; Kavitha, L; Ferreira, JMF
nossos autores
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)agradecimentos
One of the authors D. Gopi acknowledges the major financial support from the Indian Council of Medical Research (ICMR, IRIS ID No. 2010-08660, Ref. No: 5/20/11(Bio)/10-NCD-I), Department of Science and Technology (DST-SERC, Ref. No: SR/FTP/ETA-04/2009 and DST-TSD, Ref. No.: DST/TSG/NTS/2011/73) and Council of Scientific and Industrial Research (CSIR, Ref. No.: 01(2547)/11/EMR-II), New Delhi, India in the form of major research projects. Another author (J. Indira) wishes to thank the Council of Scientific and Industrial Research (CSIR), New Delhi, India for the award of Senior Research Fellowship (CSIR-SRF). L. Kavitha acknowledges the financial support from International Centre for Theoretical Physics (ICTP), Italy in the form of Junior Associateship. The support from CICECO, University of Aveiro, Portugal is also acknowledged.