Functionalization, Supramolecular Encapsulation, and Order in Boron-Nitride Nanostructures

William Marsh Rice University, Houston TX

Investigators

Abstract

Professors Angel A. Martí and Matteo Pasquali of William Marsh Rice University are supported by the Macromolecular, Supramolecular and Nanochemistry (MSN) Program in the Division of Chemistry to develop chemical strategies to control the structure and to impart desirable properties to nanostructures, particularly boron nitride nanotubes. This is to be accomplished through chemical modification of the surface, encapsulation of metal-organic complexes within the nanotubes and surface coverage with surfactants. Boron-nitrides possess a unique set of material properties that include good thermal conductivity, a large band gap, chemical inertness, and high tensile strength. Better understanding of these unique nanostructures and their properties could pave the way for the development of new sensors, anti-corrosive coatings, and light and robust materials for a wide range of applications. In the course of conducting the proposed research, graduate, undergraduate and high school students will be trained through participation in the project. Particular emphasis is on outreach toward members of underrepresented minorities at Rice University through institutional programs and in Puerto Rico through programs such as the Louis Stokes Alliance for Minority Participation. In addition, the project includes collaboration with NASA Langley Research Center and a startup company, BNNT LLC. Boron nitride nanostructures are known to be inert and extremely stable and resistant to chemical manipulation. This project focuses on the chemical modification of boron nitride nanotubes (BNNTs) and other BN nanostructures in an effort to control their organization and impart properties for potential practical applications. This goal is to be achieved by studying unexplored functionalization techniques such as the Vilsmeier reaction and the photo-decomposition of diazonium salts to functionalize BN nanostructures under mild conditions. Functionalization is designed to tune the surface properties of the BN nanostructures to modify the surface energy and dispersibility and/or achieve exfoliation. The BNNTs will be loaded with metal complexes and metal oxide nanoparticles to produce hybrid structures, and allow for the tuning of the properties of BNNTs and the encapsulated group. This research will also address the organization and self-assembly of BN nanostructures through attempts to form liquid crystalline phases by utilizing a number of surfactant preparations. The structure of the surfactants around the BNNTs will then be investigated using small angle neutron scattering. New scientific and technological advances and applications based on BN nanostructures are expected to be realized in the course of this research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.