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Heat Transfer in Polymers Summer Research 2008

Melissa Cederqvist Dr. Justin Houseknecht Dr. Douglas Dudis Chemistry & Computational Science Departments Wittenberg University, Springfield OH Wright Patterson Air Force Base, Dayton OH. Heat Transfer in Polymers Summer Research 2008. Outline. Introduction Methods Results Next step.

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Heat Transfer in Polymers Summer Research 2008

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  1. Melissa Cederqvist Dr. Justin Houseknecht Dr. Douglas Dudis Chemistry & Computational Science Departments Wittenberg University, Springfield OH Wright Patterson Air Force Base, Dayton OH Heat Transfer in PolymersSummer Research 2008

  2. Outline • Introduction • Methods • Results • Next step http://www.wittenberg.edu http://www.wpafb.af.mil/

  3. Heat Transfer in Polymers • Heat dissipation • Materials and Manufacturing directorate Wright Patterson Air Force Base • Classical Molecular Dynamics simulations • Changes in molecular motion • EPON 862 & DETDA

  4. Crosslinked polymer EPON-862 & DETDA EPON-862 DETDA “Heat Transfer in Polymers” hand out from Dr. Justin Houseknecht, Wittenberg University

  5. Molecular Dynamics • A computer approach to statistical mechanics • Calculation of structure and properties for large systems • Motion • Nave, R. Georgia State University. June 9, 2008. <http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/heatra.html#c1>

  6. Purpose • Are classical molecular dynamics simulations useful for study of heat flow? • Heat • Molecular motion • Low frequency vibrations • Classical molecular dynamics uses molecular mechanics • Parameterized for high frequency vibrations

  7. Molecular Mechanics • Mathematical method to model the shape of molecules • Parameterized • Young, D. Computational Chemistry: A Practical Guide for Applying Techniques to Real World Problems. New York: John Wiley & Sons, Inc. 2001. p. 49-52p; p.60-62

  8. Ab initio • Based on interactions between nuclei and electrons • No electron correlation • Not parameterized • Long time, no molecular dynamics • Analyze ability of molecular mechanics to calculate low frequency vibrations

  9. Adressing the problem • Calculate low frequency vibrations for a small portion of polymer • Molecular mechanics (parameterized) • MMFF • DREIDING • UFF • Semi-empirical (parameterized) • AM1 • Ab initio (not parameterized) • HF/6-31G* • HF/6-31+G* • Repeat molecular dynamics calculations with similar models Cramer, Christopher J. Essentials of Computational Chemistry – Theories and Models. 2nd ed. West Sussex, England: John Wiley & Sons, Inc. 2006. p. 165-167.

  10. Geometry optimization • Build unit of EPON-862 DETDA • Monomer at 20.2 Å • Dimer at 39.0 Å • Optimize • MMFF • Select five lowest energy conformations • AM1 • HF/6-31G* • HF/6-31+G* File: F:\Calculations\Monomer\Locked\MMFF\Conformational search\MCederqvistEPON-862 DETDA 1OPT9bconfirmsearch2-20.2.M001.spartan

  11. Geometry optimization • Similarity analysis • Measure dihedral angle for atoms 1,2,3,4; 2,3,4,5 etc. in structure From file: F:\Calculations\Monomer\Locked\RHF631+Gd\Monomer001HFlocked2.spartan

  12. Similarity analysis: Monomer From file: F:\Analysis\Monomer\Monomersimilarity.xlsx

  13. Similarity analysis: Dimer From file: F:\Analysis\Dimer\Dimersimilarity.xlsx

  14. Energy: Monomer Conformation chosen Lowest energy File:F:\Analysis\Monomer \Energy.xlsx

  15. Geometry optimization: Result • Monomer001 File: F:\Calculations\Monomer\Locked\RHF631Gd\Conformational search\Monomer001HFlocked.spartan

  16. Energy: Dimer Conformation chosen Lowest energy File: F:\Analysis\Dimer\Energy.xlsx

  17. Geometry optimization: Result • Dimer035 File: F:\Calculations\Dimer\Locked\RHF631Gd\dimer035HFlocked.spartan

  18. Frequency analysis

  19. Frequency analysis at HF/6-31+G*:A

  20. Frequency analysis at HF/6-31+G*:A

  21. LAMMPS • Large-scale Atomic/Molecular Massively Parallel Simulator • Sandia National Laboratories • US Department of Energy laboratory • Classical Molecular Dynamics simulation • Model atomic, polymeric, biomolecular systems • Systems of a few to billions of particles LAMMPS. Sandia Laboratories. May 21, 2008. June 23, 2008. http://lammps.sandia.gov/

  22. LAMMPS • Simulate heating Enter Exit Exit Unit of EPON-862 DETDA

  23. LAMMPS • Temperature vs. distance • Insulator • Conductor Enter Exit Exit T Conductor Insulator Unit of EPON-862 DETDA r r r

  24. References Cramer, Christopher J. Essentials of Computational Chemistry – Theories and Models. 2nd ed. West Sussex, England: John Wiley & Sons, Inc. 2006. p. 165-167. Houseknecht, Justin. PhD. “Heat Transfer in Polymers”. Wittenberg University. May 2008. LAMMPS. Sandia Laboratories. May 21, 2008. June 23, 2008. http://lammps.sandia.gov/ Nave, R. Georgia State University. June 9, 2008. http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/heatra.html#c1 The College of St. Scholastica. June 16, 2008. http://faculty.css.edu/lmcgahey/web/CHM220/conform/diClEt.html Young, D. Computational Chemistry: A Practical Guide for Applying Techniques to Real World Problems. New York: John Wiley & Sons, Inc. 2001. p. 19-21; 49-52p; 60-62; 78-82 Wittenberg University. June 23, 2008. http://www.wittenberg.edu/ Wright Patterson Air Force Base. June 23, 2008. http://www.wpafb.af.mil/

  25. Frequency analysis at HF/6-31+G*:NA

  26. Frequency analysis at HF/6-31+G*:NA

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