High-Pressure Study of Two Polymorphs of 2,4,6-Trinitrotoluene Using Neutron Powder Diffraction and Density Functional Theory Methods
Journal of Physical Chemistry C, vol.123, no.43, pp.26095-26105, 2019 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 123 Issue: 43
- Publication Date: 2019
- Doi Number: 10.1021/acs.jpcc.9b07658
- Journal Name: Journal of Physical Chemistry C
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.26095-26105
- Open Archive Collection: AVESIS Open Access Collection
- Police Academy Affiliated: Yes
Abstract
Copyright © 2019 American Chemical Society.A high-pressure neutron diffraction study was conducted on polycrystalline samples of the two known polymorphs of 2,4,6-trinitrotoluene [monoclinic (m) and orthorhombic (o) TNT] under hydrostatic conditions. Isothermal equations of state were obtained for both polymorphic forms. Neither polymorph was observed to undergo a phase transition in the pressure region 0-5 GPa, with both polymorphs displaying smooth compression behavior across the pressure range. This differs somewhat from previous X-ray diffraction and Raman spectroscopy investigations in which discontinuities were observed in the P-V curves and spectral changes were reported at â2 GPa. The high-pressure response of these materials is supported by dispersion-corrected density functional theory calculations which, while overestimating the experimental bulk moduli, give excellent agreement with the observed smooth compression response of both phases.