Metathesis Routes to Ultra-Incompressible Borides, High Surface Area Nitrides and Intermetallics

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Solid-state metathesis (exchange) reactions can enable the rapid synthesis of materials that are difficult to prepare by conventional methods. This project will explore new routes to high surface area titanium nitride, ultra-incompressible transition metal diborides and structural intermetallics. Since metathesis reactions produce crystalline materials within seconds due to growth in a molten salt matrix, crystallite size and surface area can be controlled with appropriate additives. Titanium nitride, an electrically conductive refractory ceramic used in electrodes for super-capacitors, will be synthesized to test this hypothesis. A new class of ultra-incompressible, hard materials will be created by combining high electron density metals, such as osmium, with small covalently bonded main group elements such as boron. Genetic algorithms will be developed that enable metathesis reactions to be optimized while running a minimum number of reactions. Graduate students will learn synthesis, characterization and measuring of physical properties through collaborations both within the chemistry department and with materials science, mechanical engineering and industrial partners. Undergraduates, including those from under-represented groups, will assist the graduate students in research, thereby enhancing the future graduate student pool in materials chemistry. A new course is being developed entitled "It's a Material World" that will enable both science and non-science majors to gain a better understanding of the importance of materials in the real world. The curriculum developed for this course will then be reconfigured and used to reach a broader audience from grade school children through alumni. The modern world is based on developing new and improved materials such as doped silicon to run computers and synthetic diamond for cutting through rock to build roads. Solid-state metathesis (exchange) reactions can enable the rapid synthesis of materials that are difficult to prepare by conventional methods. Since metathesis reactions produce crystalline materials within seconds, due to growth in a molten salt matrix, the size of the crystal grains and their surface area can be controlled with appropriate additives. Titanium nitride, which is an electrically conductive high temperature ceramic used in electrodes for rapidly chargeable and dischargeable energy storage devices known as super-capacitors, will be synthesized to test this hypothesis. A new class of ultra-incompressible, hard materials will be created by combining high density metals, such as osmium, with small main group elements such as boron. Computer codes, known as genetic algorithms, will be developed that enable metathesis reactions to be optimized while running a minimum number of reactions. Graduate students will learn synthesis, characterization and measuring of physical properties through collaborations both within the chemistry department and with materials science, mechanical engineering and industrial partners. Undergraduates, including those from under-represented groups, will assist the graduate students in research, thereby enhancing the future graduate student pool in materials chemistry.