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HERO ID
3860652
Reference Type
Journal Article
Title
Rheological Properties of PFPE Lubricants at Elevated Temperatures
Author(s)
Chung, P; Song, W; Biegler, LT; Jhon, MS
Year
2016
Is Peer Reviewed?
Yes
Journal
I E E E Transactions on Magnetics
ISSN:
0018-9464
Publisher
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Location
PISCATAWAY
Volume
52
Issue
7
DOI
10.1109/TMAG.2015.2510963
Web of Science Id
WOS:000379924800073
Abstract
During the intermittent contact between the head and the disk of the hard disk drive (HDD), the perfluoropolyether (PFPE) lubricant experiences shear/ elongation deformation. Therefore, the molecular rheology of PFPE becomes critically important in designing optimal lubricants that control the friction and wear. In this paper, we examine, for the first time, the rheological responses of nanoblended PFPEs, including storage and loss moduli (G' and G ''), by monitoring the time-dependent stress-strain relationship via nonequilibrium molecular dynamics simulations. We observed that the nonfunctional PFPEs (Fomblin Z-type) exhibit liquid-like behavior, while agglomeration behavior was observed for the functional PFPEs (Fomblin Zdol-type). In addition, strong endgroup couplings due to functional endgroup weaken as the temperature increases. For binary blended PFPEs, we also observed similar phenomena, which strongly depends on the blend ratio and imposed condition (e.g., temperature and oscillatory frequency). We established a finger print analysis via G'-G '' plots for different blend ratios and temperatures. By analyzing the blended PFPE relaxation processes, our results provide the optimal parameters for lubricant selection criteria to enhance the HDD performance.
Keywords
Binary blends; Cole-Cole plot; nonequilibrium molecular dynamics (NEMD); perfluoropolyethers (PFPEs); rheology
Conference Name
13th Joint Magnetism and Magnetic Materials (MMM)/Intermag Conference
Conference Location
San Diego, CA
Tags
PFAS
•
Additional PFAS (formerly XAgency)
Literature Search November 2019
Web of Science
Not prioritized for screening
Perfluoropentanesulfonic acid
•
Expanded PFAS SEM (formerly PFAS 430)
Perfluoropentanesulfonate
•
^Per- and Polyfluoroalkyl Substances (PFAS)
PFPeS (2706-91-4)
Literature Search
WOS
•
PFPeS
Literature Search
WOS
Screening Results
Excluded/Not on Topic
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