Database for Mechanical and Thermal Properties of Carbon Nanotubes in Nanocomposites
Board Location: #92
Discipline: Technology and Engineering
Subcategory: civil/mechanical/industrial
Session: 3
Clint Deshawn Caldwell - Elizabeth City State University
Co-Author(s): Clint Caldwell Luz Vazquez Rivera Qimora Mason Rogelio Lopze Bonilla Abdennaceur Karoui
Abstract
Carbon nanotubes (CNTs) are recognized for their exceptional mechanical, thermal, and electrical properties, making them foundational materials for future nanocomposites with applications in aerospace, electronics, and energy sectors. We are interested in understanding the CNT mechanical and thermal properties under extreme operation conditions.
Properties of CNTs under extreme deformation and within the plastic mode and heat conditions are not published. We hypothesis that the thermal and mechanical properties of CNT in plastic regime can be obtained accurately from molecular dynamics (MD) simulations. We first studied the principles of molecular dynamics. Next, we used LAMMPS to simulate CNT properties under varying control parameters of strain and temperature, to investigate CNT behavior under extreme heat and pressure conditions. Simulated tensile, compressive, and shear force tests were conducted to evaluate mechanical properties and thermal conductivity. From the analysis of stress-strain curves, we obtained Young’s modulus, yield stress, and plastic deformation parameters. Additionally, thermomechanical properties such as heat capacity under varying stresses were determined. The simulations accounted for CNT chirality and surface modifications affecting CNT behavior. Validation was conducted using experimental data and literature references.
Simulated tensile tests demonstrate the remarkable durability of CNTs. The tensile test revealed an elastic modulus of 749.8 GPa and a plastic modulus of 206.9 GPa during the initial loading. The fracture is the breaking point at which the tension on the tube has reached its maximum and snaps. The stress at the fracture came to be 189.8 GPa when the tube snapped, at that instance the strain was 0.4032. CNTs with higher aspect ratios and specific alignments exhibit superior mechanical properties, while thermal analysis suggests excellent heat transfer capabilities. The plastic regime dominated by the hardening and fracturing modalities show S-curves in the stress-strain curve. Ongoing simulations aim to refine these findings, focusing on the interfacial properties between CNTs and the polymer matrix to maximize performance.
In conclusion, the results highlight the potential of MD and LAMMPS for developing a comprehensive database of CNT properties. The development of such database has started. We believe the database will support future innovations as it will provide accessible data on CNT performance in elastic mode as well as under extreme conditions for a wide range of chirality. Future work will expand the database to include more complex systems, such as multi-walled CNTs, and explore their behavior under high-impact and thermal stress.
Funder Acknowledgement(s): I would like to thank the NNSA funding agency Award# DE-NA0004112, the NSF EiR Award number 2401243the Consortium for Nuclear Security Advanced Manufacturing enhanced by Machine Learning.
Faculty Advisor: Abdennaceur Karoui, abkaroui@ecsu.edu
Role: My role is to test for these mechanical and thermal properties of CNTs with the use of Molecular Dynamics and Lammps.