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1 poly(etheretherketone)/strontium, cerium co-substituted hydroxyapatite composite coating 2 developed on surface treated surgical grade stainless steel for orthopedic applications 3 4 ABSTRACT 16 17In the present investigation, the sulphonated poly(etheretherketone)/strontium, cerium co-18 substituted hydroxyapatite (S-PEEK/Sr,Ce-HAp) composite coating is obtained on the high 19 energy low current DC electron beam (HELCDEB) treated 316L stainless steel (316L SS) by 20 electrodeposition. The surface of 316L SS was treated using HELCDEB with energy of 500 keV 21 and beam current of 1.5 mA. The as-formed coatings on HELCDEB treated 316L SS were 22 characterised by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and 23 High resolution scanning electron microscopy (HRSEM). Electrochemical results show that the 24 S-PEEK/Sr,Ce-HAp coating with optimum 2 wt.% S-PEEK concentration on HELCDEB treated 25 316L SS possesses maximum corrosion resistance in Ringer's solution. The antibacterial activity 26 and in-vitro bioactivity of the composite coatings were investigated. The results revealed that the 27 HELCDEB treatment on 316L SS improved anticorrosion performance and also the combination 28 of S-PEEK and Sr,Ce-HAp in the coating greatly improved the bioactivity and biocompatibility 29 of the as-developed composite coating on HELCDEB treated 316L SS.30 20 in calcium site. Among these ions, Ce 3+ has been used as antibacterial agent in different 21 biomedical fields for a long time owing to the high safety and broad range of antibacterial 22 activity. Ce 3+ ions in the small quantities are imperative for a variety of metabolic processes in the 23 majority of the living microorganisms. Several in vitro studies reported that the Ce 3+ ions in the 24 1 adhesion. 25 There are three most important mechanisms for the antibacterial properties of Ce 3+ 2 ions. First, Ce 3+ ions bind to proteins and deactivate them. Second, Ce 3+ ions interact with 3 microbial membrane by causing structural change and permeability. Finally, Ce 3+ ions can 4 interact with microbial nucleic acids, which prevent microbial replication. 26-28 5 Thus the Sr 2+ and Ce 3+ , as important metal ions, were found to be very effective in 6 enhancing the structural stability, biological and antibacterial property of Ca-HAp. Recently Gopi 7 et al., have achieved the synthesis of Sr 2+ and Ce 3+ co-substituted HAp (Sr,Ce-HAp) 8 nanoparticles with increased bioactivity and antibacterial activity. 22 9 Considerable research attentions have been recently directed towards the mixer of 10 polymers with inorganic materials that shows excellent features with homogenous mechanical 11 properties. 29 The addition of polymer in the HAp at ambient temperature reduces its brittleness. 12 Among all the polymers, Polyetheretherketone (PEEK) is a biocompatible, stable and safe 13 thermoplastic polymer suitable for orthopedic applications. 30,31 It is perfectly matched for in vivo 14 medical device applications as it combines excellent chemical and hydrol...

The present work aims to investigate the effects of mineral (strontium, magnesium and zinc) substituted hydroxyapatite (M-HAP) coating on high-energy low-current DC electron beam (HELCDEB)-treated titanium (Ti).

Hydroxyapatite (HAP) is the most suitable nontoxic, biocompatible material increasingly used for bone implant coatings. However, its brittle nature is a major obstacle for such applications and this leads to the focus on developing composite coatings with the incorporation of various biopolymers and reinforcing material. In this study, mineral-substituted hydroxyapatite (M-HAP) and carboxymethyl chitosan (CMC), a biopolymer, are made into a composite (CMC/M-HAP) for enhanced biological properties of HAP. Furthermore, carbon nanotubes (CNTs) are incorporated in the composite to improve the mechanical and anticorrosive properties of HAP. The present work investigates the development of CNTs/CMC/M-HAP composite coating on piranha-treated Ti-6Al-4V alloy for improved biological and mechanical properties, which is anticipated to be the most suited alternative material for orthopedic implants.

The corrosion and corrosion inhibition of mild steel in groundwater using 1-(2-pyrrolecarbonyl)-benzotriazole (PBTA) and 1-(2-thienylcarbonyl)-benzotriazole (TBTA) with 2-phosphonoacetic acid (PAA), 4-phosphonobutyric acid (PBA), and Zn2+ at various temperatures ranging from 30 to 60 °C were reported. The study was performed using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) along with X-ray diffraction (XRD) and Scanning electron microscopy (SEM) investigations. PDP measurements proved that the presence of inhibitors decreases the corrosion of still by decreasing its corrosion current density. EIS data showed that the charge transfer resistance of steel increases in the groundwater containing inhibitors. XRD and SEM investigations confirmed that the inhibition of mild steel is achieved by the adsorption of the inhibitor molecules on the steel surface. All results indicated that the presence of PBTA and TBTA along with Zn2+ as well as PBA offered good inhibition efficiency against corrosion of mild steel in the groundwater media.

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