A Raman spectroscopy and rheology study of the phase transitions of the ionic liquid choline acetate

Autor(es)

de Souza, Icaro F. T. ^[1] ; Ribeiro, Mauro C. C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, Lab Espectroscopia Mol, Av Prof Linea Prestes 748, BR-5508000 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MOLECULAR LIQUIDS; v. 322, JAN 15 2021.
• Citações Web of Science: 0

Resumo

Melting of the ionic liquid choline acetate, {[}Chol]{[}Ac], at similar to 335 K is manifest in the differential scanning calorimetry (DSC) curve as a broad band covering similar to 30 K of temperature range. The events taking place in the pre-melting of {[}Chol]{[}Ac] are revealed by Raman spectroscopy and rheological measurements. The low-frequency range of the Raman spectrum exhibits changes in the intermolecular vibrational modes and the higher frequency range indicates conformational changes of the choline cation. Oscillatory rheological measurements show that the sample experiences a stiffening of its rheological characteristics within the temperature interval encompassing the melting process. Taking together the spectroscopic and rheological data, it is concluded that the sample experiences partial recrystallization during the pre-melting of {[}Chol]{[}Ac]. (C) 2020 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 17/23051-0 - Transições de fases, estrutura e reologia de líquidos iônicos
• Beneficiário: Ícaro Francescato Tavares de Souza
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 16/21070-5 - Espectroscopia vibracional com resolução espacial
• Beneficiário: Mauro Carlos Costa Ribeiro
• Modalidade de apoio: Auxílio à Pesquisa - Temático