Phase transitions, structure, and rheology of ionic liquids

• Grant number: 17/23051-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: March 01, 2018
• End date: February 28, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Mauro Carlos Costa Ribeiro
• Grantee: Ícaro Francescato Tavares de Souza
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 16/21070-5 - Vibrational spectroscopy with spatial resolution, AP.TEM

Abstract

The research lines going on at LEM/IQ-USP will be broadened in this project by rheological studies of ionic liquids. The work will focus in subgroups known as protic and acidic ionic liquids. The common characteristic feature of these two subgroups is the presence of an available proton for hydrogen bonding. Previous works carried out at LEM/IQ-USP indicated three dimensional networks between anions and cations, e.g. propylammonium nitrate, or one dimensional structures, e.g. chains of hydrogensulfate anions ([HSO4]-)n. These structures allow for protonic conduction in the hydrogen bond network. The project aims to obtain the phase diagrams by simultaneous changing of temperature and pressure in diamond anvil cells coupled to cryostat available for Raman spectroscopy at LEM/IQ-USP and for x-ray diffraction measurements at Brazilian Synchroton Light Laboratory (LNLS, Campinas). The consequences of the hydrogen bond network on the liquid viscoelasticity will be unraveled by the storage and loss moduli (G' e G") obtained by oscillatory tests with amplitude and frequency sweep in rheological measurements as a function of temperature. Therefore, the project will be performed in view of two aims: building up phase diagrams and understanding at molecular level the elastic and viscous features of ionic liquids. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE SOUZA, ICARO F. T.; RIBEIRO, MAURO C. C.. A Raman spectroscopy and rheology study of the phase transitions of the ionic liquid choline acetate. JOURNAL OF MOLECULAR LIQUIDS, v. 322, JAN 15 2021. (17/23051-0, 16/21070-5)

DE SOUZA, ICARO F. T.; RIBEIRO, MAURO C. C.. Understanding ion-ion and ion-urea interactions in mixtures of urea and choline oxyanions salts. JOURNAL OF MOLECULAR LIQUIDS, v. 379, p. 9-pg., 2023-03-22. (17/23051-0, 16/21070-5)