Magnetic Resonance study of structural and dynamic properties of amorphous materials

• Grant number: 11/05863-1
• Support type: Regular Research Grants
• Duration: August 01, 2011 - July 31, 2013
• Field of knowledge: Physical Sciences and Mathematics - Physics
• Principal Investigator: Jose Pedro Donoso Gonzalez
• Grantee: Jose Pedro Donoso Gonzalez
• Home Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Assoc. researchers: Caio Eduardo de Campos Tambelli ; Claudio José Magon

Abstract

This project consists of two subprojects that use the nuclear and electronic magnetic resonance techniques for the (1) characterization of the local symmetry of paramagnetic centers in nano-structured materials and (2) investigation of transport mechanisms in vitreous and polymeric ionic conductors. The first subproject involve the study of a laminar clay (bentonite), where the intercalated Cu(II) ion is complexed with an amine or porfirine, and of a series of nano-structures based on vanadium oxide (nano-tubes and nano-urchins). The second subproject is related to the study of a series of polymeric electrolytes based in chitosan, prepared with weak acid to promote protonic conduction and, also, to the study of fluorosilicates glasses and glass-ceramics SiO2 - PbF2 - CdF2. The global objectives of these studies include the characterization of the ion dynamics responsible for the observed conductivity, identification of the dominant interactions and determination of the relaxation mechanisms. Polymeric electrolytes, as well as ionic conductors, are complex systems due to the fact that the ion dynamics occur in a disordered state. Correlation between macroscopic properties (such as conductivity) and dynamics information obtained from NMR studies, as a function of temperature, will be investigated. (AU)