C.B. Minor
University of Utah,
United States
Keywords: carbon nanotubes, CNT, CNT synthesis, molten salt synthesis, climate change
Summary:
Carbon nanotubes (CNTs) have garnered attention for their exceptional properties, including high conductivity, strength, and low weight. Realizing their potential for macro-scale applications, however, depends on the development of high-quality CNT wires, which remains a challenge due to limitations in current production methods. This study proposes a novel approach to producing high-performance CNT wires by integrating the synthesis and alignment of CNTs into a single, concurrent process. The investigation explores the viability of this approach through a comprehensive analysis of growth mechanisms, electrical supply, electrode composition, salt composition, and overall process compatibility. This presentation aims to provide an in-depth evaluation of the proposed method, exploring its potential and theoretical feasibility for advancing CNT wire manufacturing. The proposed method combines two key techniques: dielectrophoresis for CNT alignment and molten salt electrolysis for CNT synthesis. In the proposed technique, the processes of electrolytic CNT synthesis and dielectrophoretic CNT wire formation are integrated into a single, concurrent process. This synergistic and continuous process has potential as a novel synthesis method for macro-scale CNT wire with properties as significant as its nanoscale counterpart, CNTs. Integration of these two processes presents several challenges in process compatibility, including current type and electrode morphology. In molten salt electrolytic synthesis of CNTs, atmospheric carbon dioxide is absorbed and utilized as a carbon source to form carbon nanotubes, enabling a continuously renewable process. Traditional methodology involves applying direct current (DC) through electrodes, which facilitate electrochemical reactions involving the ions in the molten salts. In the proposed method, this technique is adapted to use an alternating current (AC) electric field to facilitate dielectrophoresis. Dielectrophoresis involves the use of an AC field to induce polarization in nanoparticles, resulting in end-to-end attraction and thus alignment of CNTs. The use of AC fields in molten salt electrolysis is unexplored, and requires innovative design considerations. To serve the role of electrodes, metallic nanoparticles will be integrated into the molten salt composition, through which the AC field induces a current. These metallic nanoparticles serve as nucleation points for CNT growth. Atomic-level control of CNT growth may be possible through the synchronization of current pulses with bond formation as rings of carbon are added. This will be investigated as a strategy to prevent CNT termination, promoting the growth of longer CNTs. The significant number of independent inputs in this method suggest superior tunability of CNT properties, including length, diameter, and chirality. If successful, this approach could revolutionize CNT wire production, making it scalable and fit for applications including electric motors and transmission wires. The implications of this research extend beyond CNT synthesis. The proposed method aligns with efforts to mitigate climate change by incorporating carbon dioxide absorption into CNT production, building off of existing molten salt electrolysis techniques. This presentation will outline the hypothesis, address potential challenges, and discuss experimental design for validating this approach. I aim to stimulate discussion and collaboration within the nanotechnology community to advance this promising field of research.