Compositional and Temperature Controls on Structural Order, Dynamics, and Properties of Multicomponent Borosilicate Glasses

Stanford University, Stanford CA

Investigators

Abstract

NON-TECHNICAL DESCRIPTION Borosilicate glasses are widely used in technology, with applications ranging from heat- and chemical-resistant glassware and reaction vessels, to reinforcement fibers in ?fiber-glass?, to computer and television display screens. Many of these are central to multi-billion dollar U.S. industries, such as flat-panel TV?s and computer monitors. The atomic-scale structure of these materials controls their properties, which must be tailored to improve performance in their diverse uses. This project seeks to understand general principles of how variations in the glass composition, and the way that it is heat-treated during manufacturing, change the glass structure in useful ways, to allow properties to be more easily predicted and engineered. The results of these studies should have more general interest as well, in other fields of science where glasses (and the liquids that form glass on cooling) are important, including geosciences and condensed-matter physics. Education is central to this project, since most of the research will be part of the training of Ph.D. and undergraduate students on their ways to careers in science and engineering. TECHNICAL DETAILS The most important experimental approach that will be used is solid-state nuclear magnetic resonance (NMR) spectroscopy, which provides quantitative details about the structure around many of the components common in technological glasses, including boron, aluminum, silicon, and oxygen. The P.I. and students in this program will synthesize several series of glasses with systematic variations in composition, and measure how glass structure changes. They will vary the thermal history of the glasses to look for clearly important, but poorly-known, effects of temperature. They will analyze results with thermodynamic modeling to allow prediction of critical properties. Much of the current development of improved and new types of glass materials comes from trial-and-error experimentation; it is thus an important goal to develop more fundamental understanding of structure-property relationships. Success with this goal could lead to new ways of thinking about designing glass compositions for new applications. Given major efforts in fundamental glass science in other countries, and the importance of the manufacturing of high-tech glasses in U.S. industry, it seems particularly urgent to progress in more basic understanding of these materials.