Educational Activities for 2006

1. Cycloadditions functionalizations to preserve or control the conductance of carbon nanotubesNicola Marzari, Massachusetts Institute of TechnologyDMR-0304019 Most covalent functionalizations destroy the electrical conductance of metallic nanotubes (Lee, Nardelli and Marzari, PRL05). In this recent work (Lee and Marzari, PRL06), we discovered that cycloadditions of carbenes or nitrenes on single-wall tubes with diameters below 2 nm break the sidewall bond (in red, top right panel) and restore sp2 hybridization (in green, top left panel). In the process, the carbon nanotubes regain the conductance of pristine ones (bottom panel, in green, the case of an infinite metallic (10,10) SWNT functionalized with 30 dicyanocarbenes along a central segment 43 nm long). For certain molecules, such as the dicyanocarbene pictured here, an optical excitation could switch the system to a locally stable state in which the sidewall bond is intact, and the conductance greatly decreased (bottom panel, in red)

2. Educational Activities for 2006 • NSF workshop at the Virtual Lab for Earth and Planetary materials, U. of Minnesota (1 week, lecturer) • NSF school on “Ab-initio molecular dynamics” at the Materials Computation Center – UIUC (2 weeks, organizer and lecturer) • “Building nanostructures bit-by-bit”, 2nd Annual NNIN/CNF Fall Workshop at the Cornell NSF nanoscale facility (2 days, lecturer) • 8th Giambiagi school on Computational Materials Science, University of Buenos Aires (3 days of lectures) • Asian-Pacific college on nanoscience, Insitute of Physics, Beijing (3 days of lectures) • Bangalore Summer School on “Electronic-structure methods and their applications”, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore. (1 week, lecturer, preceded by 3-day conference on Computational Materials Science). Photo above (~8 US students attended, with NSF support)