Near-Tg crystallization in super-cooled liquids and glasses

• Grant number: 15/01848-9
• Support type: Research Grants - Visiting Researcher Grant - International
• Duration: July 01, 2015 - September 30, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal researcher: Edgar Dutra Zanotto
• Grantee: Edgar Dutra Zanotto
• Visiting researcher: Prabhat Kumar Gupta
• Visiting researcher institution: Ohio State University, Columbus, United States
• Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass, AP.CEPID

Abstract

We shall research and develop new active glasses and glass-ceramics presenting application-relevant functionalities, such as high mechanical strength and electrical conductivity, biological, optical or catalytic activity, and/or combinations of these properties. A fundamental understanding of these properties will be sought on the basis of the structural organization of these materials on different length scales. We will apply state-of-the art NMR, EPR, EXAFS and vibrational spectroscopy to characterize the local and medium-range order, as well as the full resolution range of optical and electron microscopies, XRD and microanalyses for elucidating nano- and microstructures. This comprehensive experimental approach will be complemented by molecular dynamics simulations. Using this experimental modeling strategy, we will further seek a fundamental understanding of glass sintering and crystallization in terms of the mechanisms, thermodynamics and kinetics of viscous now, as well as crystal nucleation and growth, enabling us to exercise control of these processes by developing appropriate forming process and thermal treatment protocols. In a concerted effort, the participating laboratories will jointly investigate a number of important benchmark systems, which are deemed particularly promising for applications either as structural reinforcement materials (dental and bio glass-ceramics), optical materials (laser glasses), materials for electrochemical energy storage devices (electrolytes, high-temperature seals), and catalytically active systems. Prof. Gupta will participate in our CEPID project FAPESP #2013/07793-6. He will work on the fundamental understanding of glass crystallization in terms of the mechanisms, thermodynamics and kinetics of crystal nucleation and growth, and relaxation in deep undercooled glasses (at ~Tg). (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)

GUPTA, PRABHAT K.; CASSAR, DANIEL R.; ZANOTTO, EDGAR D. Role of dynamic heterogeneities in crystal nucleation kinetics in an oxide supercooled liquid. Journal of Chemical Physics, v. 145, n. 21 DEC 21 2016. Web of Science Citations: 13.

GUPTA, PRABHAT K.; CASSAR, DANIEL R.; ZANOTTO, EDGAR D. On the variation of the maximum crystal nucleation rate temperature with glass transition temperature. Journal of Non-Crystalline Solids, v. 442, p. 34-39, JUN 15 2016. Web of Science Citations: 4.