The use of the NiTi alloy in the medical application has increased recently, since it has better functional fatigue and biocompatibility than other shape memory alloys (SMA) material such as CuZnAl and CuAlNi. Although, many applications of NiTi for bio-functional materials have been implemented, however the safety issues of this alloy in human body is still under investigations. Nickel, the element found in NiTi, is a toxic and causes allergy. it has been reported that around twenty percent of woman in Europe had the allergy due to the use of nickel. The safety of the use of NiTi as the biomaterial can be improved by means of minimizing the release of nickel to the human tissues. Graphene, which is one of two-dimensional carbon materials is an ideal candidate for implant surface coatings, since it is very stable, atomically smooth, and very durable. Some experimental works of graphene coating on nitinol has been conducted. Graphene can be grown on the NiTi surface via chemical vapor deposition (CVD) method using the hydrocarbon such as methane as the carbon precursor molecule. In order to understand the complete mechanism of graphene growth on the NiTi surface, we will at first investigate the physics of methane dissociation on the NiTi surface using density functional theory (DFT) calculation.
Density functional theory, methane, dissociation, NiTi surface
This research aims to elucidate the mechanism of methane dissociation on NiTi surfaces. This should provide the valuable information of the initial stage of graphene growth on NiTi from a microscopically view point. Therefore, it would complement the experimental research on this topic.
The Quantum Espresso package will be utilized in this calculation. At first, we will calculate the adsorption energy of the methane and its fragments on several sites of the NiTi (001) and NiTi (111) surface. The reaction route will be determined from the lowest adsorption energy of methane fragments on the NiTi surface. Finally, the Nudged Elastic Band (NEB) method will be employed to search the minimum energy path (MEP) and to estimate the activation energy of the reaction.
Dr. Rizal Arifin (Faculty of Engineering, Universitas Muhammadiyah Ponorogo)
Munaji, M.Si. (Faculty of Engineering, Universitas Muhammadiyah Ponorogo)
Dr. Veronica M. Sanchez (Researcher at CSC-CONICET Argentina)
Software: Quantum Espresso (QE) Package
Temporary Data Storage: 100 GB
Processor Core Hours: 2160 hours
Publication in the Journal of Physical Chemistry C (or any similar journal)
20/01/2018 - 20/04/2018