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Vijayshankar Asokan: Amorphous nanoparticles into nanotubes: Transformational behavior of carbon black particles - with and without catalysts

posted 8 Aug 2014, 06:19 by Lisbeth Kirk Mynster
Vijayshankar Asokan, Dorte Nørgaard Madsen, Department of Physics and Technology, University of Bergen, Norway, 5007 

CB is a well-known type of amorphous carbon which exists in the form of aggregated spheres. It lies in the category of non-graphitizable carbon. Many bent and faceted layer planes and few closed-shell structures could be obtained when CB was treated at high temperature and however carbon undergoes structural transformation when it comes in contact with metal catalysts at high temperature. The degree of transformation and morphology of resulting nanostructure depends on many factors which this project takes into consideration and studied. In this work, an easy, economical and single-step process for the transformation of CB into a large quantities of metal-encapsulated multi-walled carbon nanobeads (MWNB) and multi-walled carbon nanotubes (MWNT) is carried out. Further, this works studied the possibilities of transformation CB into a nano-onions and nanofibers using microwave energy with and without use of any metal catalysts respectively. Process of transformation of CB particles is studied with respect to temperature, inert gas, metal catalysts (Ni, Fe) and their weight ratios with respect to CB taken during experiment. Electron microscopes (Scanning, transmission and high-resolution transmission), Raman spectroscopy, Thermal gravimetry analysis, X-ray diffraction methods are used for the characterization of these samples. 

Vijayshankar Asokan is currently a PhD research student at University of Bergen, Norway. He is primarily interested in the synthesis and characterization of nanomaterials, thin films. He received his B.Sc. degree in Applied Sciences from Coimbatore Institute of Technology, India (2004), MSc degree in Materials Science from PSG College of Technology (2006), India. He joined University of Bergen in May 2008 as PhD research fellow and his research area includes synthesis of carbon nanotubes and surface functionalization of nano carbon for fuel cell applications and has expertise in the operations of thin film systems (thermal evaporation, sputtering, chemical vapor deposition and electron beam evaporation) and different material characterization methods includes Scanning electron microscope, Transmission electron microscope, High-resolution transmission electron microscope, Particle size analyzer, Zeta potential measurements, surface area analyzer, Raman and UV/IR Spectroscopy, Electrochemical impedance spectroscopy.