Polymers and Composites Group
Participants
Molecular Dynamics Simulation
Our effort since the fall semester of 2007 was aimed at developing an original molecular dynamics simulation program to study the physical properties of long chain molecules
and composites. Our starting point was a code that was previously initiated and developed in the spring of 2007. However, improvements in flexibility, scope, and effectively
handling constraints inherent in the geometry of the polymer under consideration were needed. Another important goal was to enhance the capability of the code to find a global
minimum of the potential energy. These improvements have been accomplished. The program can be run on a network of computers to increase efficiency as well as capability. We have
used the program in the simulation of polyethylene chain consisting of 152 monomer units for about 100 picoseconds. It is possible to increase the number of monomers without
difficulty. Stress strain curves have been generated using the simulation maintaining a temperature of 300 degree Kelvin. We have also generated accompanying curves for the total
energy. With the view to study the relaxation behaviour in the atomistic configuration of polydisperse polyethylene melts we have implemented a simulation at 450 degree Kelvin to
compute various parameters such as self-diffusion constants, relaxation parameters. Some of these results are documented in a manuscript we are currently developing (see below).
For practical applications, such as the study of the dynamics of polymers, nanocomposites, polymer viscoelasticity, and polymer flows, it is critical to generate appropriate start
configurations.
Thus, currently initiated efforts include modeling of the dynamic simulation of polyethylene, and polyethylene melts. Other initiated efforts deal with the modeling, and dynamic
simulation of polymeric flows, carbon nanotube and polymer composite. To study the physical properties of carbon nanotubes, and composites we have to further develop a supplemental
simulation code.
Simulation of a polyethylene chain over 100ps kept at a temperature of 300K.
| Polyethylene chain | Potential energy | Kinetic energy |
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| Total energy | Temperature | Stress |
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Last updated: 09/10/2008
