Metalloid Cluster Building Blocks and their Inclusion within Composite Networks
Abstract
Project Summary: The research team will develop a program to synthesize metalloid clusters and small metalloid nanoparticles ("nanoclusters"), assemble them into networks, and tune their properties by varying cluster size and network structure. Metalloid clusters, such as Al77[N(SiMe3)2]202-, have been of interest for years due to their potential use as energetic materials, catalysts, optical and magnetic compounds. The main impediment to studying and developing wide ranges of metalloid clusters has been the difficulty of preparing bulk quantities of these compounds and packaging them into useful forms. The metalloid cluster size regime (~100 - 200 atoms) is in between the more stable classes of molecular clusters and bulk nanoparticles, which makes their synthesis and isolation particularly challenging. Similarly, nanoclusters must be protected lest a substantial mass fraction of the particle oxidize. The research team comprises leading experts in metalloid cluster synthesis (Bowen and Eichhorn), metalloid nanocluster synthesis (Anderson and Zachariah), network structures (Long) and theoretical modeling (Hooper and Mueller). We will develop new, non-traditional synthetic protocols (e.g. framework-directed cluster synthesis, gas phase co-condensation, reactive ball milling), employ state-of-the-art techniques (e.g. pulsed electric discharge cluster sources, counter propagating electrostatic assembly) and couple experiment with theory through database construction and multi-scale modeling (e.g. ab initio simulations, kinetic Monte Carlo). The primary goals of the program are to develop general protocols for metalloid cluster and nanocluster synthesis, develop a theoretical framework to understand and predict properties, and prepare and characterize a series of metalloid clusters and cluster network structures. We are particularly interested in the evolution of structures and properties of metalloid clusters as they transition from the molecular regime into the bulk regime by way of small, ligated nanoclusters. Such knowledge will provide the framework for targeting optimal size and composition regimes for future cluster based materials in specific applications. The team will target a selected series of main group metalloid clusters (Si, Mg, B, Ge, Sn), since these elements cross the metal-to-non-metal border and are likely to possess an interesting range of properties, as well as a selected group of transition metals (Fe, Co, Mn, Pt), because these bulk elements have important magnetic and catalytic properties. Metalloid clusters and cluster networks have a wide range of potential impacts on DoD capabilities, including use as energetic materials, obscurants, and catalysts in electrical generation and storage devices (fuel cells and batteries). The fundamental knowledge generated through the proposed work herein would help advance these goals.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512681
Entities
People
- Kit H Bowen
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy