GOALI: Development of Inorganic Phosphate Glass Matrix Nanocomposites Incorporating Nanoscale Polyhedral Oligomeric Silsesquioxanes with Improved Properties

University Of Southern Mississippi, Hattiesburg MS

Investigators

Abstract

NON-TECHNICAL: This Grant Opportunities for Academic Liaison with Industry research project concerns the development of optically transparent glass matrix nanocomposite, wherein special molecular silica is chemically incorporated into ultra-low melting phosphate glass. The hypothesis of the proposed research is that molecular-level combination during liquid-state processing of reinforcing molecular silica and phosphate glass matrix at similar molecular-level length scales has the potential to offer significantly improved optical and mechanical properties for a number of applications. The ability to easily manufacture intricate shapes of the nanocomposites by liquid-state processing in an extruder at relatively low temperatures (250°C), to reinforce glass with molecular silica, and to potential self-healing of glass via low-temperature annealing offer distinctive transformative alternatives to conventional glass and ceramics materials processing and design. This project plays an important role in the Nation's current interest in developing micro- and nano-length scale materials and processing technologies. The project provides useful training for two graduate students and a number of research experiences for undergraduate students in a vital area of research, making significant impact on the future economic development of the U.S. in the area of nanostructured 'optically transparent' inorganic glass matrix nanocomposites materials. Recruiting women and other underrepresented minorities (e.g., ethnic, disabled, geographic) from the University of Southern Mississippi's sizable minority student population is an important objective of this project. TECHNICAL DETAILS: This cooperative research effort between Southern Mississippi University and industry (Hybrid Plastics, Inc.) investigates how incorporation of small amounts of a well-defined nanostructured inorganic cluster or molecular silica can be used to tune morphological, rheological and strength and fracture toughness of 'optically transparent' molecular silica/phosphate glass matrix nanocomposites system. The discovery of new knowledge and phenomena are prerequisites to inventing new applications. As well, the diversification of research approaches coupled with cooperation is critical for the best progress. In particular, the academic-industry liaison provides critical guidance and a clear focus for the creation and refinement of highly relevance materials for a range of applications. The special molecular silica which is manufactured by the industrial partner of this project consists of an eight-corner, silica-based cage bearing one or more prescribed functional groups to yield a new class of innovative molecular silica/phosphate glass matrix nanocomposites that combines transparency (optical clarity) and improved strength and fracture toughness for special security uses. By using a variety of complementary methods, the project explores the molecular origin of the structure, rheological properties and thermo-mechanical behavior of well-characterized molecular silica/phosphate glass matrix nanocomposites, making it possible to define mechanisms that develop on nanometer length scales, influence the microscale, and impact the macroscale. Because the nano-polyhedral oligomeric silsesquioxanes (POSS) merges the properties of nanofillers with the precision of chemistry and the molecular silica cage length scale (i.e., 1.5 nm) approaches the short-range structure of phosphate glass, it is conjectured that unique interactions develop that give rise to optimal control of the nanocomposite properties such as strength, fracture toughness and light transmittance.