title: Dispersibility of vapor phase oxygen and nitrogen functionalized multi-walled carbon nanotubes in various organic solvents.
abstract: The synthesis and characterization of gas phase oxygen- and nitrogen-functionalized multi-walled carbon nanotubes (OMWCNTs and NMWCNTs) and the dispersibility of these tubes in organic solvents were investigated. Recently, carbon nanotubes have shown supreme capacity to effectively enhance the efficiency of organic solar cells (OSCs). A critical challenge is to individualize tubes from their bundles in order to provide homogenous nano-domains in the active layer of OSCs. OMWCNTs and NMWCNTs were synthesized via HNO3 vapor and NH3 treatments, respectively. Surface functional groups and the structure of the tubes were analyzed by temperature-programmed desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, and Raman spectroscopy which confirmed the formation of functional groups on the tube surface and the enhancement of surface defects. Elemental analysis demonstrated that the oxygen and nitrogen content increased with increasing treatment time of the multi-walled carbon nanotube (MWCNT) in HNO3 vapor. According to ultra-violet visible spectroscopy, modification of the MWCNT increased the extinction coefficients of the tubes owing to enhanced compatibility of the functionalized tubes with organic matrices.
authors.affiliation: Institute for Materials Science and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstraße 15, 45141 Essen, Germany.
authors.forename: Maryam
authors.initials: M
authors.lastname: Khazaee
authors.affiliation: Laboratory of Industrial Chemistry, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Wei
authors.initials: W
authors.lastname: Xia
authors.affiliation: Institute for Materials Science and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstraße 15, 45141 Essen, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Lackner
authors.affiliation: Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstraße 20, D-01069 Dresden, Germany.
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Mendes
authors.affiliation: Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstraße 20, D-01069 Dresden, Germany.|Center of Polymer and Carbon Materials, Polish Academy of Sciences, M. Curie-Sklodowskiej 34, Zabrze 41-819, Poland.|College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.
authors.forename: Mark
authors.initials: M
authors.lastname: Rümmeli
authors.affiliation: Laboratory of Industrial Chemistry, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Muhler
authors.affiliation: Institute for Materials Science and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstraße 15, 45141 Essen, Germany.
authors.forename: Doru C
authors.initials: DC
authors.lastname: Lupascu