Day 2 :
Keynote Forum
Anirudha V Sumant
Argonne National Laboratory, USA
Keynote: Towards developing energy efficient systems based on novel carbon materials
Time : 10:30 - 11:15
Biography:
Anirudha Sumant is a Materials Scientist working at Center for Nanoscale Materials, Argonne National leading the research on nanocarbon materials including CVD-diamond, carbon nanotube and graphene. He has more than 22 years of research experience in the synthesis, characterization and developing applications of carbon based materials. His main research interests include electronic, mechanical and tribological properties of carbon based materials, surface chemistry, micro/ nano-scale tribology, and micro-nanofabrication. He is the author and co-author of more than 100 peer reviewed journal publications, 2 book chapters, winner of four R&D 100 awards, NASA Tech Brief Magazine Award, 2016 TechConnect National Innovation Award, has 16 patents granted, and 15 pending and given numerous invited talks. His research in diamond materials helped in the formation of several start-up companies including NCD Technologies Inc. and AKHAN Semiconductors Inc. He is a member of MRS, STLE and AVS.
Abstract:
Minimizing friction and wear-related mechanical failures remains as one of the greatest challenges in today’s moving mechanical systems leading to a search for new materials that can reduce friction and wear related energy losses and the understanding of fundamental mechanisms that control friction. In this context, our work on graphene has shown that this materials properties can be manipulated at the atomic level to achieve exceptionally high wear resistance, as well as well as achievement of superlubricity (or near zero friction) at macroscale through combined use of graphene and nanodiamonds on sliding surfaces [1]. This discovery presents a paradigm shift in understanding frictional behavior of graphene and other 2D materials and offers a direct pathway for designing energy efficient frictionless tribological systems. In the second part of my talk, I’ll describe our recent work on direct growth of wafer-scale graphene on diamond. The fact that the one atom thick graphene membrane strongly affected by the substrate interactions puts limit on exploiting excellent intrinsic properties of graphene for various applications. Diamond offers multiple unique properties, such as high phonon energy, low trap density, and high thermal conductivity, which make it an ideal substrate for fabricating graphene devices on diamond [2]. We demonstrate a novel process to grow large area single and few layer graphene directly on the diamond thin film deposited on silicon wafer thus eliminating the need for graphene transfer [3]. This approach offers new opportunities for developing graphene based nanoelectronic devices directly on dielectric substrate (diamond/Si) and provides reliable, efficient and low cost alternative as compare to current methods.
Keynote Forum
Somnath Bhattacharyya
University of the Witwatersrand, Johannesburg, South Africa
Keynote: Quantum device prospects of superconducting diamond films
Time : 11:45 - 12:30
Biography:
Somnath Bhattacharyya is a Professor in the School of Physics at the University of the Witwatersrand, Johannesburg, South Africa focusing on the area of condensed matter physics and nano-electronics. His major interest is in the transport properties of carbon and major achievements include the demonstration of resonant tunnel devices based on amorphous carbon, gigahertz transport in carbon devices, n-type doping of nanocrystalline diamond and developing theoretical models for transport in disordered carbon. His team focuses on the fabrication of the nanoelectronic devices, studying novel electronic properties of nanocrystalline diamond films and carbon superlattice structures at high magnetic fields and high frequencies. His group is also involved in performing theoretical modeling of carbon quantum structures. He is engaged in developing a new infrastructure for a wider range of nanotechnology that will include quantum matter, carbon based microwave detectors and nano- bio-electronics.
Abstract:
Nanostructured semiconducting carbon system, described by as a superlattice-like structure demonstrated its potential in switching device applications based on the quantum tunneling through the insulating carbon layer [1-4]. This switching property can be enhanced further with the association of Josephson’s tunneling between two superconducting carbon (diamond) grains separated by a very thin layer of carbon which holds the structure of the film firmly [5]. The superconducting nanodiamond heterostructures form qubits which can lead to the development of quantum computers provided the effect of disorder present in these structure can be firmly understood. Presently we concentrate on electrical transport properties of heavily boron–doped nanocrystalline diamond films around the superconducting transition temperature measured as a function of magnetic fields and the applied bias current. We demonstrate signature of anomalous negative Hall resistance in these films close to the superconductor-insulator-normal phase transition at low bias currents at zero magnetic field [5]. Current vs. voltage characteristics show signature of Josephson-like behavior which can give rise to a characteristic frequency of several hundred of gigahertz. Signature of spin flipping also shows novel spintronic device applications. We are working towards utilizing the superconducting phenomena in nanodiamond films in making some novel quantum electronic and high speed devices. This project complements our previous work on nitrogen-doped nanodiamond films and related nanostructured carbon devices which showed interesting radio frequency features in the gigahertz range [6].
- Speaker Session - Large scale Graphene production and characterization | Applications of graphene in Energy and Biomedicals | Graphene modification and functionalization | Graphene Synthesis | Carbon nanotubes and Graphene
Location: International B
Chair
Ram K. Gupta
Pittsburg State University, USA
Session Introduction
Manawadevi Y Udugala-Ganehenege
University of Peradeniya, Sri Lanka
Title: Application of carbon and metal based catalysts for the utilization of carbon dioxide and bio-waste to get renewable energy
Time : 14:00 - 14:30
Biography:
Prof. Manawadevi Y. Udugala-Ganehenege has completed her PhD in 2000 from Wayne State University (WSU), Michigan and postdoctoral studies from Monash University School of Chemistry in Australia. She is currently a professor in Inorganic Chemistry of University of Peradeniya, Sri Lanka. Her main research interest is on utilization of carbon dioxide and bio-waste for renewable energy. She has received numerous prestigious fellowships and awards for her academic excellence and research, including 2000 Esther and Stanley Kirshner Graduate Award and 1995-Thomas Rumble Fellowship from WSU, 2011- Endeavour Awards from Australian government, and 2016 and 2017 Presidential Awards from Sri Lankan government.
Abstract:
Magnetic and electrochemical studies of face-to–face arranged, tetraaza-macrocyclic homo-bimetallic (Metal= Ni, Cu) complexes revealed a significant affinity towards halide ions, and an interesting metal-metal interaction through a halide bridge. With an intention for finding a solution to reduce the environmental pollution caused by CO2 emission, I studied the ability of these metal complexes to utilize CO2 electochemically. The outcome of this attempt ultimately revealed that these complexes were better electro-catalysts for the conversion of very inert CO2 into useful chemicals such as carbonates and oxalates.
By integrating the knowledge on electrocatalytic activity of these metal complexes to utilize CO2, a novel Al3+, Fe3+ modified graphene oxide composite (GO) was synthesized with an intention to apply it as a heterogeneous catalyst for the pre-esterification of the bio-oil containing a high level of free fatty acids (FFA). These GO composite had shown a very efficient capacity for the pre-esterification of FFA. It showed 92.72 % conversion of stearic acid into methyl stearate and 95.37 % reduction of FFA content of Calophyllum inophyllum oil. The conversion was conducted under mild reaction conditions. The optimum catalytic dose, reaction time and temperature employed were of 8% (wt.), 3 h and 65 0C, respectively. The catalyst could be easily recovered and reused more than four cycles, effectively. The subsequent employment of pre-esterified Calophyllum inophyllum oil produced biodiesel with 86% yield without encountering unnecessary soap formation.
George Paskalov
Plasma Microsystem LLC, USA
Title: Application of carbon nanotubes to protect plasma torch electrodes
Time : 14:30 - 15:00
Biography:
George Paskalov has completed his PhD at the age of 24years from Polytechnical University (St Petersburg, Russia). He is CEO of Plasma Microsystem LLC (Los Angeles, CA), a plasma research and development company. He has published more than 100 papers and presentations, and more than 13 patents. He also has been serving as board member for a few more companies.
Abstract:
The lifetime of plasma torch electrodes is critical, however, it is usually limited to 200 hours. Here we report a direct current arc plasma torch with cathode lifetime significantly exceeded 1000 hours. To ensure the electrodes’ long life a process of hydrocarbon gas (propane/butane) dissociation in the electric arc discharge is used. In accordance with this method, atoms and ions of carbon from near-electrode plasma deposit on the active surface of the electrodes and form a carbon condensate in the form of carbon nanotubes. It operates as an “actual” electrode. To realize aforesaid the construction of a plasma torch using air as the plasma forming gas has been developed and tested. For long-term electrode operation, carbon nanotubes are ideal materials. They have high electron emission and are chemically inert at high electric field strengths. Carbon nanotubes’ conductivity is superior to all conventional conductors, they can withstand current density 100 times greater than metals, and they have high heat conductivity. They are very mechanically firm, 1000 times more firm than steel and they gain the properties of semiconductors at their curling or flexion. On the basis of atomic force microscopy, scanning electron microscopy, transmission electron microscopy and Raman-spectroscopy investigation it was concluded that the cathode condensate consists mainly of single and multi-walled carbon nanotubes and other nanoforms. The lifetime of the reported cathode totals more than 1000 hours. The experiments reported here confirm the possibility for an unlimited lifetime of the cathode coated with composite nanocarbon layer.
Eimutis Juzeliūnas
Centre for Physical Sciences and Technology, Lithuania
Title: Electrochemical synthesis of photoactive carbon-carbide structures on silicon
Time : 15:00 - 15:30
Biography:
Professor Eimutis Juzeliiūnas is the principal research associate at the Centre for Physical Sciences and Technology in Vilnius, Lithuania. His recent research areas include silicon electrochemistry for energy applications, environmental and microbiological degradation of metallic materials, PVD alloys, molten salt electrochemistry. The research leading to these results has received funding from the European Commission 7th Framework Programme under grant agreement PIOF-GA-300501.
Abstract:
Carbon-silicon compositions are promising to improve light harvesting performance of silicon-based solar cells. Silicon modification by carbon species could increase light absorbance and accelerate photoelectron generation. Procedures of chemical or physical vapor deposition as well as various etchings are typically used to improve antireflection performance of silicon surface. Most of these techniques, however, are not cost effective and also include hazardous reactants. We demonstrate an environmentally friendly electrochemical method of silicon surface modification by a carbon-carbide system in molten calcium chloride. Silicon-carbon-carbide compositions were obtained by polarizing silicon-silica precursor in molten calcium chloride electrolyte using a graphite anode. A reaction scheme is discussed, which includes release of oxygen from silica, its interaction with a graphite electrode and reduction of carbon dioxide by calcium metal. Structure and composition of the structures have been studied by EDX, XRD, and XPS. Semiconductor properties of the structures have been studied by Mott-Schottky characteristics, EIS and photo electrochemistry. High photoactivity of the structures is demonstrated. The surfaces absorbed over 90% of white light in a broad region of wavelengths from 400 nm to 1100 nm. The proposed method offers new opportunities for production of carbon-modified silicon surfaces with superior antireflection and protective properties for solar devices, photoelectrodes, sensors and catalytic supports.
Carmen Greice Renda
Federal University of São Carlos, Brazil
Title: Ferrocene thermal decomposition during phenolic resins graphitization
Time : 16:00 - 16:30
Biography:
Carmen Greice Renda is pursuing her PhD in the Federal University of Sao Carlos. She is a civil engineer with a master in Materials Science and Engineering. She has published papers in reputed journals and has been working with polymers and ceramics materials
Abstract:
Carbonaceous materials have been promised to sensors, biomedicine, magnetic data storage, etc. Nowadays the studies about catalytic graphitization of phenolic resins with several graphitization agents (as ferrocene, boron oxide, graphite, etc.) have been increased. Depending on these materials synthesis it is possible to obtain many types of products as MWNT with the iron particles, nano-shell, and onion-like-carbon structures. This work is intended to see the effects of increasing temperature during the catalytic graphitization of phenolic resins with the ferrocene decomposition. The structure, the properties, the graphitization level and the phases formed are observed by 13C-NMR, Raman, X-Ray Diffraction, Impedance and 57Fe-Mossbauer Spectroscopies, Electron Paramagnetic Resonance (EPR) and Magnetic Hysteresis. The results 13C-NMR, Raman, X-Ray Diffraction and Impedance Spectroscopy are confirmed the graphitization level is increased during the ferrocene decomposition forming a multi-phases material and the iron phases impacts in the percolation electrical threshold. The EPR is demonstrated the ions interaction Fe+3 pulled out of the material. The 57Fe-Mossbauer Spectroscopy are concluded the most part of the iron phases is composed by hematite and maghemite. The magnetic hysteresis is evidenced by the ferromagnetic properties.