This Article describes research on chemical reactions on molecules attached to the surface of silicon quantum dots that have been performed to produce quantum dots with reactive surface functionalities such as diols and epoxides. Characterization of the surface reactions includes NMR and FT-IR studies, and the quantum dots were characterized by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Cytotoxicity and cell viability assay conducted on silicon dots capped with polar molecules indicated low toxicity with quantum dots with more reactive functionalities found to be more toxic. The silicon quantum dots photoluminesce and have been used as a blue chromophore for the biological imaging of cells.

Figure S1. Thermogravimetric analysis (black line) and differential thermal analysis (blue line) of Au nanoparticles coated with oleylamine. The feature in the differential thermal analysis at 165°C, and the drop in weight at the same temperature, indicate the initial removal of the oleylamine surfactant.Thermal analysis was performed using an Alphatech SDT Q600 thermoanalyser under flowing air (50 mL/min) at a heating rate of 10 °C/min.

We report on a real-time in situ TEM study of the coalescence of individual pairs of decahedral gold nanoparticles, which have been synthesized in solution. We observe the rate of growth of the neck that joins two particles during coalescence and compare this to classical continuum theory and to atomistic kinetic Monte Carlo simulations. We find good agreement between the observations and the simulations but not with the classical continuum model. This disagreement is attributed to the faceted nature of the particles.

Field emission (FE) has been extensively explored from various exotic low dimensional carbon nanomaterials, such as amorphous carbon films, 1 single and multiwalled carbon nanotubes (CNTs), 2 tubular graphitic cones, 3 vertically aligned nanowalls, 4 few-layered graphene (FLG) nanoflakes, 5,6 and, more recently, from doped and pristine graphene. 7,8 Graphene, a two-dimensional monatomic plane layer of hexagonally arrayed sp 2-hybridized carbon atoms forms the backbone of all the above-mentioned carbon nanostructures. 9 The highly desirable properties of graphene, such as atomic thickness, excellent electrical conductivity, and high aspect ratio, make it an ideal candidate for field emission applications. 7-9 Also, as compared to CNTs, the presence of a large number of edges may render graphene superior for electron tunneling. 7 Although FE in CNTs is highly efficient, it has been shown that heteroatom doping by elements, such as nitrogen, can further reduce the effective tunneling potential barrier, thereby reducing the turn-on field and significantly increasing the electron emission current. 10,11 Nitrogen acts as an electron donor in CNTs because it has five valence electrons and causes a shift in the Fermi level (E F) to the conduction band and increases the electron density of states (DOS). In the case of graphene, theoretical studies have shown that substitutional heteroatom doping can modulate the band structure of graphene, leading to a metal-semiconductor transition, thereby expanding the applications of graphene. 12,13 Although Malesevic et al. 5 and Qi et al. 6 have shown the field emission behavior of pristine and Ar plasma-treated FLG nanoflakes, respectively, to the best of our knowledge, until now, there ' EXPERIMENTAL SECTION The synthesis of FLGs was carried out in a SEKI MPECVD deposition system, equipped with a 1.5 kW, 2.45 GHz microwave source. The substrates used were bare n-type heavily doped Si wafers (resistivity < 0.005 Ω cm) (10 mm  10 mm). Prior to growth, the substrates were pretreated with N 2 plasma at 650 W at 40 Torr while the substrate temperature was maintained at 900°C. Synthesis was then carried out using CH 4 /N 2 (gas flow