Inelastic ultraviolet scattering study of the collective dynamics of ionic liquids

• Grant number: 16/19703-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: January 16, 2017
• End date: January 15, 2018
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Mauro Carlos Costa Ribeiro
• Grantee: Vitor Hugo Paschoal
• Supervisor: Tullio Scopigno
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Università degli Studi di Roma La Sapienza, Italy
• Associated to the scholarship: 15/07516-8 - Collective dynamics of ionic liquids, BP.DD

Abstract

The project to which this BEPE proposal is related, entitled "Collective dynamics of ionic liquids", FAPESP process 2015/07516-8 has as part of its objectives the determination of the acoustic dispersion curves, i.e., determination of the excitation energy of the acoustic modes as a function of their wavevector (or momentum transfer) for different ionic liquids and their Li+ solutions. The determination of these dispersion curves helps to probe the possible correlations between their elastic behavior in the high-frequency range (THz) and their microscopic structure. This study may add to the comprehension of some aspects of the glass transition and of the origin of the boson peak, both unanswered question in material sciences. The internship at Università di Roma "La Sapienza", under supervision of Prof. Tullio Scopino, opens new perspectives of collaboration and knowledge exchange between both research groups. Both groups work in the themes of liquid state theory and in the high frequency dynamics of these systems using different experimental and theoretical approaches which should favor this exchange. The inelastic ultraviolet scattering (IUVS) measurements, which are currently unavailable in Brazil, associated with molecular dynamics simulations (MD), and low-frequency Raman spectroscopy measurements, currently being made, will allow exploring the relation between dynamics and structure of these ionic liquids. Besides the results of the IUVS measurements may provide data that will allow critical evaluation of the robustness and transferability of the polarizable force field being proposed. Therefore, this internship will also contribute to expand the data set obtained by both experimental and computational methods. (AU)