Molecular Modeling of Polymers

The modeling of polymer materials, and the simulation of thermo-mechanics and other properties of polymer are very different from inorganic materials and organic small molecule materials. On the one hand, the huge molecular weight of polymer molecules and the huge degree of freedom in the chain bring great difficulties to atomic-level modeling and calculations. On the other hand, polymer systems have many unique thermo-mechanical properties, such as glass transition, viscoelasticity and dynamic modulus, etc. In addition, the interaction between polymer segments and other segments, small molecules, surfaces, and nanoparticles is also very different from other organic systems. Molecular modeling methods cover all theories and calculation methods used to model or imitate molecular behavior, and the common feature of molecular modeling methods is the atomic-level description of molecular systems. Molecular modeling methods are used in molecular systems ranging from small chemical systems to large-scale biomolecules and material assembly. Alfa Chemistry provides various molecular modeling tools to support the construction of multiple polymer models.

Figure 1. Approaches to molecular modelling of supramolecular polymers. (Bochicchio,D.; PAVAN, G. M. 2018)

Polymer System

• Thermoplastic
• Thermoset polymer
• Linear homopolymers and copolymers
• Crosslinked polymer
• Polymer single chain and melt
• Polymers with embedded small molecules
• Compound model with single molecules, nanoparticles, surface
• User-defined monomer structure

Molecular Modeling Procedure of Polymers

1. Select the monomers of polymer sequences that are stored in the Monomer Database
We can build one main monomer chain or the polymer chains consisting more than two monomers randomly or alternatively.

2. In the Polymer Environment, we set up the polymer density and embeded host configuration and molecules.
We build melted polymer with a defined density controlling a periodic box size. But in the embedded case with a host configuraiton, polymers are packed in the periodic box of host configuration.
We can also setup to build polymer with embedded other material types.

3. Monte Carlo is applied for polymer melts construction

4. Equilibration
Focre-capped molecular dynamics are used for initial equilibration.
Single-Chain Mean-Field (SCMF) is applied for further equilibration.
Energy minimization for relaxing the polymer system.

Features of Our Molecular Modeling

• Simulation methods

Molecular dynamics in the NVE, NVT and NPT ensembles.
Time-stamped Forced-bias Monte Carlo (TFMC) simulation for enhanced equilibration and simulating events over longer timescales.
Non-equilibrium momentum exchange for modeling heat transfer in polymer systems.

• Advanced techniques

Hook functions to implement customized simulation techniques and measurements in molecular dynamics.
Metadynamics simulations.

• Automated amorphous polymer model modeling tool
• Automated tools supporting graphical user interface (GUI) and Python scripting
• Automatic force field generation, support DREIDING, OPLS-AA and UFF
• Charge equilibration using Qeq and ReaxFF charge equilibration methods
• Cross-linking reaction tools

What we Offer?

• Thermo-mechanical properties of polymer melts

For example, the stress-strain molecular dynamics (MD) method is used to calculate the Young's modulus of a polymer melt

• Glass transition of polymers

Through reasonable control of the heating process, the glass transition process of the polymer can be simulated to obtain T_g.

Application of Our Services

• Thermo-mechanical properties
• Glass transition, elasticity, dynamic modulus, viscosity
• Heat Conduction
• Polymer compatibility
• Polymer performance under high deformation, high shear rate, and high heating/cooling rate
• Simulate polymer systems with specific chemical components
• Interactions between polymer segments, interactions between polymer segments and other molecules
• Polymer melt wrapped around nanoparticles and surfaces

Our molecular modeling of polymers services remarkably reduce the cost, promote further experiments, and enhance the understanding of chemical process for customers worldwide. Our personalized and all-around services will satisfy your innovative study demands. If you are interested in our services, please don't hesitate to contact us. We are glad to cooperate with you and witness your success!

Reference

• Bochicchio,D.; PAVAN, G. M. PavanMolecular modelling of supramolecular polymers. ADVANCES IN PHYSICS: X. 2018, 3(1): 317-338.