N. Rajendran

Bio: N. Rajendran is an academic researcher from Anna University. The author has contributed to research in topics: Dielectric spectroscopy & Corrosion. The author has an hindex of 22, co-authored 61 publications receiving 1215 citations. Previous affiliations of N. Rajendran include National Institute for Materials Science.

A Review on TiO2 Nanotubes: Influence of Anodization Parameters, Formation Mechanism, Properties, Corrosion Behavior, and Biomedical Applications

Abstract: In this article, influence of anodization parameters on the formation of tubes, tube dimensions, formation mechanism, properties of TiO2 nanotubes (TNT), and their applications in biomedical field are reviewed. The fabrication of TNT of a different shape such as pore size, length, and wall thickness by varying anodization parameters including electrolytes, pH, voltage, electrolyte bath temperature, and current density is examined and discussed. The crystallographic nature of the nanotube obtained by various methods has also been discussed. Finally, the article concludes by examining the key properties including the corrosion aspect and various applications in biomedical field in depth.

Novel sol gel coating of Nb2O5 on magnesium alloy for biomedical applications

Abstract: In recent years, magnesium alloys are considered as a new class of biodegradable alloys. Though they have several favourable properties, higher susceptibility to hydrogen evolution and corrosion have limited their applications in the biomedical field. Recently, several coatings have been developed to overcome their higher degradation rate. In this regard, a new attempt has been made to develop niobium oxide (Nb 2 O 5 ) coating on magnesium alloys to increase the biocompatibility and reduce the corrosion rate. Phase structure, surface morphology and chemical composition of the coating have been studied by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy, X-ray Diffraction Analysis (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) Spectroscopy and Transmission Electron Microscopy (TEM) analysis. The prepared coating possesses good bioactivity and hydrophilicity in Simulated Body Fluid (SBF). Corrosion rate and hydrogen evolution rate were enormously controlled and the coating possesses excellent bonding strength with the substrate. The higher cell attachment and cell growth with pseudopodia extensions were observed by controlling the release of magnesium ions into the surrounding body tissue.

Surface Modification Methods for Titanium and Its Alloys and Their Corrosion Behavior in Biological Environment: A Review

Abstract: Titanium (Ti) and its alloys are being used in biomedical field owing to their low elastic modulus, good fatigue strength and formability, and corrosion resistance. However, they are still not sufficient for long-term clinical usage as they are bio-inert and they cannot bond to living bone directly at the early stage after implantation into a human body. Their surfaces play an important role in response to the artificial devices in a biological environment; for these materials to meet the clinical demands, it is necessary to modify their surface. The corrosion resistance and biological properties of Ti and its alloys can be improved selectively by using the appropriate surface modification techniques while the desirable bulk attributes of the materials are retained. The proper surface treatment expands the use of these materials in the biomedical field. This article reviews the various surface modification techniques for Ti and its alloys including mechanical methods, chemical and electrochemical treatment, thermal spraying, sol–gel, and ion implantation towards the field of biomedical engineering. A positive effect of various surface modification techniques is illustrated in this review as suggested by many research groups. Also, this article includes the corrosion behavior of surface-modified Ti and its alloys for biomedical applications.

Electrochemical Impedance Spectroscopy

Abstract: This review describes recent advances in electrochemical impedance spectroscopy (EIS) with an emphasis on its novel applications to various electrochemistry-related problems. Section 1 discusses the development of new EIS techniques to reduce measurement time. For this purpose, various forms of multisine EIS techniques were first developed via a noise signal synthesized by mixing ac waves of various frequencies, followed by fast Fourier transform of the signal and the resulting current. Subsequently, an entirely new concept was introduced in which true white noise was used as an excitation source, followed by Fourier transform of both excitation and response signals. Section 2 describes novel applications of the newly developed techniques to time-resolved impedance measurements as well as to impedance imaging. Section 3 is devoted to recent applications of EIS techniques, specifically traditional measurements in various fields with a special emphasis on biosensor detections.