MSE Seminar: Dr. Lourdes Salamanca-Riba, UMD
Wednesday, November 29, 2023
Room 2108 Chemical and Nuclear Engineering Building
301 405 5240
Nanocarbon Metal Composites Synthesized by Electrocharging Assisted Process
Abstract: Nanocarbon metal composites are desirable to take advantage of the excellent charge carrier mobility, high thermal conductivity and strength of carbon nanostructures, such as graphene and carbon nanotubes (CNT), and the high charge carrier concentration in metals. The composites are expected to have improved properties that make them unique candidates in applications such as high power transmission lines, interconnects, heat exchangers, motors, photovoltaic cells and transparent electrodes, among others. However, graphene and CNT are costly and difficult to make in large quantities. We use a process to synthesize graphitic nanostructures in metals by the application of a high electrical current to liquid metal containing particles of activated carbon. The process, called electrocharging assisted process, generates a region of very high current density which transforms the activated carbon particles from amorphous to crystalline graphitic nanoribbons. Upon solidification of the metal the nanoribbons self-assemble with an epitaxial relation with the metal. We have used Al 1350 and activated carbon particles of ~100 nm and obtained samples with global electrical conductivities more than 5% higher than the parent alloy as well as enhanced local stiffness, measured by nanoindentation. The conductivity enhancement is correlated with increasing crystallite size and concentration of the produced graphitic nanostructures. We have also deposited films of nanocarbon copper by e-beam deposition and pulsed laser deposition that show increased transmittance to light and increased oxidation resistance compared to pure copper films of the same thickness. These films could be used in transparent electrodes or interconnects. The electrocharging assisted process is universal and scalable to large scale manufacturing.
Bio: Lourdes Salamanca-Riba is a Professor at the Department of Materials Science and Engineering at the University of Maryland.