Rastogi V, Rao U, Chaurasia S, Sijoy CD, Mishra V, Chaturvedi S, Deo MN. Time-Resolved Vibrational Spectroscopy of Polytetrafluoroethylene Under Laser-Shock Compression.
APPLIED SPECTROSCOPY 2017;
71:2643-2652. [PMID:
28748703 DOI:
10.1177/0003702817726542]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Shock-wave-induced high pressure and nanosecond time-resolved Raman spectroscopic experiments were performed to examine the dynamic response of polytetrafluoroethylene (PTFE) in confinement geometry targets. Time-resolved Raman spectroscopy was used to observe the pressure-induced molecular and chemical changes on nanosecond time scale. Raman spectra were measured as a function of shock pressure in the 1.2-2.4 GPa range. Furthermore, the symmetric stretching mode at 729 cm-1 of CF2 was compared to corresponding static high-pressure measurements carried out in a diamond anvil cell, to see if any general trend can be established. The symmetric stretching mode of CF2 at 729 cm-1 is the most intense Raman transition in PTFE and is very sensitive to change in pressure. Therefore, it can also be utilized as a pressure gauge for large amplitude shock wave compression experiments. A maximum blueshift of 12 cm-1 for the 729 cm-1 vibrational mode has been observed for the present experimental pressure range. A comparative study on the similarities and differences from the earlier work has been done in detail. One-dimensional radiation hydrodynamic simulations were performed to validate our shock compression results and are in very good agreement.
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