| Full text | |
| Author(s): |
Total Authors: 4
|
| Affiliation: | [1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Lab Espectroscopia Mol, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo - Brazil
Total Affiliations: 1
|
| Document type: | Journal article |
| Source: | Journal of Molecular Structure; v. 1183, p. 149-156, MAY 5 2019. |
| Web of Science Citations: | 1 |
| Abstract | |
X-ray diffraction and Raman scattering measurements of the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesufonyl)imide, {[}Pyrr(1,4)]{[}NTf2], were performed in a wide range of temperature and pressure. Pressure dependence of glass transition T-g(p), cold-crystallization T-cc(p), and melting T-m(p) temperatures were obtained from atmospheric pressure up to ca. 2.0 GPa. The temperature dependence of Raman spectra within the T-cc < T < T-m range at atmospheric pressure unveils conformational dynamics of {[}Pyrr(1)(,4)](- )while {[}NTf2](-) remains in the transoid conformation characteristic of the crystal. The different pressure dependence of T-cc(p) and T-m(p) implies that these curves merge at ca. 330 K and 1.0 GPa. Upon the assumption that the T-g(p) curve belongs to isochronous states, T-g(p) is discussed in terms of thermodynamic scaling using low-temperature and high-pressure extrapolations of an empirical equation of state. The ratio between constant volume and constant pressure activation energies for viscous flow, E-v/E-p, increases only slightly in the pressure range investigated in this work. The results obtained under simultaneous variation of temperature and pressure highlight the complex interplay between glass transition and crystallization of {[}Pyrr(1)(,4)]{[}NTf2]. (C) 2019 Elsevier B.V. All rights reserved. (AU) | |
| FAPESP's process: | 15/05803-0 - Ionic liquid structure under high pressure |
| Grantee: | Luiz Felipe de Oliveira Faria |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 15/07516-8 - Collective dynamics of ionic liquids |
| Grantee: | Vitor Hugo Paschoal |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |
| FAPESP's process: | 14/15049-8 - A Raman spectroscopy study of the glass transition of ionic liquids under high pressure. |
| Grantee: | Thamires Andrade Lima |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 16/21070-5 - Vibrational spectroscopy with spatial resolution |
| Grantee: | Mauro Carlos Costa Ribeiro |
| Support Opportunities: | Research Projects - Thematic Grants |