Polymer Simulations with QuantumATK

Polymer simulation software using QuantumATK


QuantumATK polymer simulation software is used to design polymers with improved thermo-mechanical, thermal conductivity and optical properties within R&D of areas such as photoresist, transparent polymers and polymers used for tire and insulation industries. Polymer building and equilibration tools in QuantumATK provide reliable polymer models, which can then be simulated using fully automated workflows, powered by a highly scalable MPI parallelized molecular dynamics (MD) engine.

Benefits of QuantumATK Platform

• Flexible and user-friendly GUI streamlining the building of various polymer systems while having full control of tacticity, monomer composition, and end groups

• Fully automated workflows for equilibrating and simulating polymer systems Simulations of extended time-scales through time-stamped force-bias Monte Carlo (TFMC) simulations

• Simulations of heat transport using the Reverse Non-Equilibrium Molecular Dynamics (RNEMD) methodology

• Advanced analysis tools in the GUI, such as a glass transition temperature analyzer, temperature profile for heat transport and others to advance polymer engineering

Key advantages of QuantumATK

  • Flexible and user-friendly GUI streamlining the building of various polymer systems while having full control of tacticity, monomer composition, and end groups
  • Fully automated workflows for equilibrating and simulating polymer systems
  • Simulations of extended time-scales through time-stamped force-bias Monte Carlo (TFMC) simulations
  • Simulations of heat transport using the Reverse Non-Equilibrium Molecular Dynamics (RNEMD) methodology
  • Advanced analysis tools in the GUI, such as a glass transition temperature analyzer, temperature profile for heat transport and others to advance polymer engineering
Example of polymer blend simulation

Fig 1: Polymer – Polymer Blend

Polymer inorganic interface simulation

Fig 2: Polymer - Inorganic Interface

Polymer nanoparticle composite simulation

Fig 3: Polymer - Nanoparticle Composite

Fully Automated Polymer Simulation Workflow

Builder     

  • Large ready-to-use monomer and end-group database with possibility to add custom monomers
  • Interface to embed molecules, nanoparticles and surfaces
  • Monte Carlo builder for polymer melts

Parameter Setup

  • Automatic potential generation for DREIDING and OPLS-AA
  • More than 300 pre-defined parameter sets, including reactive ReaxFF potentials, parametrized for a wide range of organic and inorganic materials
  • Charge equilibration using QEq and ReaxFF methods

 

Equilibration Methods

  • Force-capped equilibration tools for initial equilibration
  • Single-Chain Mean-Field (SCMF) equilibration
  • Energy minimization for relaxing the polymer system
  • 21 step polymer equilibration protocol

 

Polymer simulation software

Fig 2: Polymer simulation scripter

Polymer equilibration software

Fig 3: Polymer equilibration  

Simulation Methods 

  • MD in the NVE, NVT, and NPT ensembles
  • TFMC simulations for enhanced equilibration and simulating events over longer timescales
  • RNEMD simulations of heat transport
  • Automated calculation of stress-strain curves

Advanced Techniques

  • Hook functions to implement customized simulation techniques and measurements in molecular dynamics
  • Metadynamics simulations via interface to the PLUMED package

Analysis Tools

  • Advanced analysis tools in the GUI, such as glass transition temperature analyzer, temperature profile for heat transport
  • Interactive MD trajectory analysis and movie generation
  • Highly flexible plotting framework for visualizing results.

 

Application Examples

Polymer stress and strain, Young’s modulus simulation

Stress-strain simulations (Young’s modulus)

Young’s modulus is obtained via a linear fit of the stress-strain curve calculated from stress-strain MD simulations, where the cell is strained at a constant rate in one direction at a time.

Example: Young’s modulus calculated for the photoresist co-polymer of two polymers: Poly[(4-[tert-butoxycarbonyl]oxy-styrene)-co-(4-vinylphenol)] as a function of deprotection of 4-vinylphenol monomer.

Polymer glass transition temperature simulation

Glass transition temperature studies

Glass transition temperature, Tg, is obtained via using linear fitting to determine a discontinuity in the gradient of the density over temperature plot calculated from MD simulations.

Example: TG calculated for the poly(methyl methacrylate) (PMMA) polymer melt by cooling it from 550 K to 250 K temperature.

Polymer thermal conductivity simulation

Thermal conductivity studies

Thermal conductivity is calculated from the temperature gradient due to non-equilibrium momentum exchange between heat sink and source regions in a polymer using RNEMD methodology.

Example: simulated thermal conductivity results for the poly(vinyl chloride) (PVC) polymer are in a good agreement with the experimental values, i.e., 0.14 W/mK vs 0.16 W/mK.

Polymer optical properties simulation

Optical properties

QuantumATK enables simulation and advanced analysis of a large range of optical and electro-optical parameters, such as Raman, infrared and optical spectrum, second harmonic generation susceptibility, electro-optical tensor.

Example: simulated optical spectrum  of polyethylene (PE) based on i) the traditional chain of monomers model  and ii) the more realistic polymer melt generated using QuantumATK polymer builder, which is in a better agreement with experimental results.

Learn more about QuantumATK products

Interested in applying QuantumATK software to your research? Test our software or contact us at quantumatk@synopsys.com to get more information on QuantumATK platform for atomic-scale modeling.