Electrochemical and in vitro bioactivity of polypyrrole/ceramic nanocomposite coatings on 316L SS bio-implants

摘要

The present investigation describes the versatile fabrication and characterization of a novel composite coating that consists of polypyrrole (PPy) and Nb_2O_5 nanoparticles. Integration of the two materials is achieved by electrochemical deposition on 316L stainless steel (SS) from an aqueous solution of oxalic acid containing pyrrole and Nb_2O_5 nanoparticles. Fourier transform infrared spectral (FTIR) and X-ray diffraction (XRD) studies revealed that the existence of Nb_2O_5 nanoparticles in PPy matrix with hexagonal structure. Surface morphological analysis showed that the presence of Nb_2O_5 nanoparticles strongly influenced the surface nature of the nanocomposite coated 316L SS. Micro hardness results revealed the enhanced mechanical properties of PPy nanocomposite coated 316L SS due to the addition of Nb_2O_5 nanoparticles. The electrochemical studies were carried out using cyclic polarization and electrochemical impedance spectroscopy (EIS) measurements. In order to evaluate the biocom-patibility, contact angle measurements and in vitro characterization were performed in simulated body fluid (SBF) and on MG63 osteoblast cells. The results showed that the nanocomposite coatings exhibit superior bio-compatibility and enhanced corrosion protection performance over 316L SS than pure PPy coatings.