Heat Transfer in PolymersSummer Research 2008 : Heat Transfer in PolymersSummer 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
Outline : Outline Introduction
Methods
Results
Next step http://www.wittenberg.edu
http://www.wpafb.af.mil/
Heat Transfer in Polymers : 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
Crosslinked polymer EPON-862 & DETDA : Crosslinked polymer EPON-862 & DETDA EPON-862 DETDA “Heat Transfer in Polymers” hand out from Dr. Justin Houseknecht, Wittenberg University
Molecular Dynamics : 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.
Purpose : 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
Molecular Mechanics : 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
Ab initio : 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
Adressing the problem : 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.
Geometry optimization : 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
Geometry optimization : 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
Similarity analysis: Monomer : Similarity analysis: Monomer From file: F:\Analysis\Monomer\Monomersimilarity.xlsx
Similarity analysis: Dimer : Similarity analysis: Dimer From file: F:\Analysis\Dimer\Dimersimilarity.xlsx
Energy: Monomer : Energy: Monomer File:F:\Analysis\Monomer \Energy.xlsx
Geometry optimization: Result : Geometry optimization: Result Monomer001 File: F:\Calculations\Monomer\Locked\RHF631Gd\Conformational search\Monomer001HFlocked.spartan
Energy: Dimer : Energy: Dimer File: F:\Analysis\Dimer\Energy.xlsx Conformation chosen Lowest energy
Geometry optimization: Result : Geometry optimization: Result Dimer035 File: F:\Calculations\Dimer\Locked\RHF631Gd\dimer035HFlocked.spartan
Frequency analysis : Frequency analysis
Frequency analysis at HF/6-31+G*:A : Frequency analysis at HF/6-31+G*:A
Frequency analysis at HF/6-31+G*:A : Frequency analysis at HF/6-31+G*:A
LAMMPS : 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/
LAMMPS : LAMMPS Simulate heating
LAMMPS : LAMMPS Temperature vs. distance
Insulator
Conductor r T
References : 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/
Frequency analysis at HF/6-31+G*:NA : Frequency analysis at HF/6-31+G*:NA
Frequency analysis at HF/6-31+G*:NA : Frequency analysis at HF/6-31+G*:NA