skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Colloidal structure and stabilization mechanism of aqueous solutions of unmodified fullerene C{sub 60}

Abstract

Despite the inability of fullerenes to be directly dissolved in water, there are methods for preparing stable dispersions of fullerenes in water without any particular modifications of the fullerene or addition of stabilizers. The colloidal properties of such systems prepared by replacing the solvent and structural changes in them during coagulation have been studied. The coagulation dynamics has been investigated by spectroscopy and small-angle neutron scattering. The results obtained confirm the colloidal nature of such systems. During coagulation, particles retain a large volume of water around them, an indication of interaction between fullerene and water during solution stabilization.

Authors:
;  [1];  [2];  [3]; ;  [1]
  1. Joint Institute for Nuclear Research (Russian Federation)
  2. Shevchenko National University (Ukraine)
  3. Research Institute for Solid-State Physics and Optics (Hungary)
Publication Date:
OSTI Identifier:
21090908
Resource Type:
Journal Article
Resource Relation:
Journal Name: Crystallography Reports; Journal Volume: 52; Journal Issue: 3; Other Information: DOI: 10.1134/S1063774507030273; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AQUEOUS SOLUTIONS; COLLOIDS; FULLERENES; NEUTRON DIFFRACTION; SMALL ANGLE SCATTERING; SOLVENTS; SPECTROSCOPY; STABILIZATION

Citation Formats

Khokhryakov, A. A., E-mail: art@nf.jinr.ru, Kyzyma, O. A., Bulavin, L. A., Len, A., Avdeev, M. V., and Aksenov, V. L. Colloidal structure and stabilization mechanism of aqueous solutions of unmodified fullerene C{sub 60}. United States: N. p., 2007. Web. doi:10.1134/S1063774507030273.
Khokhryakov, A. A., E-mail: art@nf.jinr.ru, Kyzyma, O. A., Bulavin, L. A., Len, A., Avdeev, M. V., & Aksenov, V. L. Colloidal structure and stabilization mechanism of aqueous solutions of unmodified fullerene C{sub 60}. United States. doi:10.1134/S1063774507030273.
Khokhryakov, A. A., E-mail: art@nf.jinr.ru, Kyzyma, O. A., Bulavin, L. A., Len, A., Avdeev, M. V., and Aksenov, V. L. Tue . "Colloidal structure and stabilization mechanism of aqueous solutions of unmodified fullerene C{sub 60}". United States. doi:10.1134/S1063774507030273.
@article{osti_21090908,
title = {Colloidal structure and stabilization mechanism of aqueous solutions of unmodified fullerene C{sub 60}},
author = {Khokhryakov, A. A., E-mail: art@nf.jinr.ru and Kyzyma, O. A. and Bulavin, L. A. and Len, A. and Avdeev, M. V. and Aksenov, V. L.},
abstractNote = {Despite the inability of fullerenes to be directly dissolved in water, there are methods for preparing stable dispersions of fullerenes in water without any particular modifications of the fullerene or addition of stabilizers. The colloidal properties of such systems prepared by replacing the solvent and structural changes in them during coagulation have been studied. The coagulation dynamics has been investigated by spectroscopy and small-angle neutron scattering. The results obtained confirm the colloidal nature of such systems. During coagulation, particles retain a large volume of water around them, an indication of interaction between fullerene and water during solution stabilization.},
doi = {10.1134/S1063774507030273},
journal = {Crystallography Reports},
number = 3,
volume = 52,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • The reactions in the C{sub 60}-(TiCl{sub 4} + Br{sub 2}) system have been performed in ampoules at elevated temperatures. The molecular structure of the fullerene halides (C{sub 60}Cl{sub 5}){sub 2}, C{sub 60}X{sub 6}, C{sub 60}X{sub 8}, and C{sub 60}X{sub 24} (X = Cl, Br) has been determined and refined using single-crystal X-ray diffraction. It has been established that an increase in the bromine concentration results in an increase in the number of halogen atoms attached to the fullerene cage and in an increase in the relative fraction of bromine atoms in mixed halogen derivatives from almost pure chlorides (C{sub 60}Cl{submore » 5}){sub 2} and C{sub 60}Cl{sub 6} to halides C{sub 60}X{sub 8} and C{sub 60}X{sub 24} with a high relative bromine content.« less
  • The self-organization of star-shaped polymers in toluene has been studied by small-angle neutron scattering. Polystyrene stars with a mono-C{sub 60} branching center are ordered into globular clusters ({approx}1700 nm in diameter), whereas stars with a double (C{sub 60}-C{sub 60}) center are ordered into anisotropic structures (superchains), which are linked (depending on the concentration) into triads (chain clusters {approx}2500 nm in diameter). On the contrary, heteroarm polystyrene and poly-2-vinylpyridine stars with a C{sub 60} center are weakly associated into dimers. Moderately polar stars with arms composed of polystyrene and diblock copolymer (poly-2-vinylpyridine-poly-tret-butyl methacrylate) form short chains composed of four macromolecules, whilemore » stars of higher polarity based on polystyrene and poly-tret-butyl methacrylate form clusters containing {approx}12 macromolecules {approx}50 nm in diameter. Thus, by varying the structure of the center and the arm polarity, one can control the modes of star structuring.« less
  • The homogeneous electrocatalytic reduction of 1,2-dihaloethanes by anions of larger fullerenes, C{sub 76}, C{sub 78}, and C{sub 84}, is presented, and structure-reactivity correlations are derived by including the data reported earlier for the C{sub 60} and C{sub 70} electrocatalytic process. Cyclic voltammetry measurements indicate that dianions of C{sub 76} and C{sub 78}, as well as trianions of C{sub 76}, C{sub 78}, and C{sub 84}, electrochemically generated in 0.1 M (TBA)PF{sub 6}, in benzonitrile, catalyze dehalogenation of 1,2-dihaloethanes. Values of the second-order rate constant, {kappa}, for the electrocatalytic dehalogenation of 1,2-dihaloethanes by the fullerene anions were determined by using the rotating-diskmore » electrode voltammetry under pseudo-first-order conditions with respect to the 1,2-dihaloethanes. For each fullerene anion, {kappa} increases in the order: Cl < Br < 1 for the investigated 1,2-dihaloethanes. Also, log {kappa} linearly increases in the order: C{sub 84} < C{sub 78} < C{sub 76} < C{sub 70} < C{sub 60}, as a function of respective redox potentials of the fullerene, for each 1,2-dihaloethane. Unlike the C{sub 60}{sup n{minus}} electrocatalysis, reported by the authors earlier to be accompanied by chemical reaction between C{sub 60}{sup n{minus}} and certain {alpha},{omega}-diiodoalkanes yielding alkyl adducts of C{sub 60}, no reaction between the anions of larger fullerenes and 1,2-dihaloethanes was observed within the voltammetric time scale. Because of the high stability with respect to adduct formation and more positive potentials of the electrocatalyses, the larger fullerenes may be more useful than C{sub 60} as catalysts, even though the corresponding catalytic rate constants are smaller.« less
  • C{sub 60} is found to dissolve in liquid triphenylantimony. Upon cooling, red crystals form which were characterized by X-ray diffraction and found to be C{sub 60}{center_dot}6SbPh{sub 3}. The quality of the crystals was excellent allowing structural determination without the presence of twinning or orientational disorder.
  • Powder samples of fullerene C{sub 60} and fullerene soot have been studied by the small-angle X-ray scattering method. The radii of gyration of scattering elements have been determined by constructing small-angle diffraction patterns in Guinier coordinates. The data obtained agree well with the results of wide-angle X-ray scattering study, the available data on the structure of the powder fullerene C{sub 60} prepared by the Huffman-Kraetschmer technique, and the structure of the C{sub 60} molecules. Conglomerates of two C{sub 60} molecules, along with crystallites {approx}20 nm in size that are distributed in an amorphous matrix, are present in fullerene powders. Fullerenemore » soot contains C{sub 60} crystallites 20-25 nm in size and graphite crystallites {approx}2-3 nm in size that are distributed in an amorphous matrix.« less