Developing a predictive structure generation methodology for molecular simulations of amorphous materials is a non-trivial task due to their complex and unordered nature. This problem is exacerbated for glassy polymers, particularly those with high-Tg’s, because of their bulky structures and slow dynamics. One focus of our research has been on the development of a general methodology, called Polymatic, for virtual synthesis of any amorphous material knowing only the chemical structure. Polymatic is composed of two parts: (i) a simulated polymerization algorithm and (ii) a 21-step molecular dynamics compression and relaxation scheme.
Simulated polymerization of polycarbonate using Polymatic:
The first step is a simulated polymerization algorithm. With this approach, bonds are made between nearby repeat units in between molecular dynamics simulations to grow well-relaxed linear or network polymeric systems. A movie showing the simulated polymerization of polycarbonate performed with Polymatic is shown above. The second step of the methodology is a 21-step molecular dynamics relaxation and compression scheme. This protocol provides adequate equilibration of the system, while also compressing it to a predicted final density consistent with experimental values. Importantly, the final structure can be obtained predictively at a variety of conditions by setting the desired final temperature and pressure accordingly.
- Virtual Synthesis of Thermally Crosslinked Copolymers from a Novel Implementation of Polymatic.
- Polymatic: A Generalized Simulated Polymerization Algorithm for Amorphous Polymers
- Molecular Simulations of PIM-1-like Polymers of Intrinsic Microporosity
- Atomistic Structure Generation and Gas Adsorption Simulations of Microporous Polymer Networks