Force field parameter estimation of functional perfluoropolyether lubricants

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3556700· OSTI ID:1015225

Smith, Robert ^[1]; Seung Chung, Pil ^[1]; Steckel, Janice A. ^[2]; Jhon, Myung S. ^[3]; Biegler, Lorenz T. ^[1]

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1. Carnegie Mellon Univ., Pittsburgh, PA (United States) Dept. of Chemical Engineering and Data Storage Systems Center
2. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)
3. Carnegie Mellon Univ., Pittsburgh, PA (United States) Dept. of Chemical Engineering and Data Storage Systems Center; Sungkyunkwan University, Suwon (Korea)

The head disk interface in a hard disk drive can be considered to be one of the hierarchical multiscale systems, which require the hybridization of multiscale modeling methods with coarse-graining procedure. However, the fundamental force field parameters are required to enable the coarse-graining procedure from atomistic/molecular scale to mesoscale models. In this paper, we investigate beyond molecular level and perform ab initio calculations to obtain the force field parameters. Intramolecular force field parameters for Zdol and Ztetraol were evaluated with truncated PFPE molecules to allow for feasible quantum calculations while still maintaining the characteristic chemical structure of the end groups. Using the harmonic approximation to the bond and angle potentials, the parameters were derived from the Hessian matrix, and the dihedral force constants are fit to the torsional energy profiles generated by a series of constrained molecular geometry optimization.

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Fossil Energy (FE)
• OSTI ID: 1015225
• Report Number(s): NETL-TPR-3507
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 7; ISSN 0021-8979: JAPIAU
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AB INITIO CALCULATIONS
CHEMICAL BONDS
MULTISCALE METHODS
ATOMIC AND MOLECULAR CLUSTERS
CHEMICAL PROPERTIES