Search

Ozonized C70fullerene known as C70ozopolymer or C70fullerene polyoxide was thermally decomposed in a Differential Scanning Calorimeter (DSC). The exothermal decomposition enthalpy was measured together with the activation energy for the thermal decomposition. The decomposition of C70ozopolymer was also studied with FT-IR spectroscopy showing that the thermal treatment at 350°C under N2causes the disappearance of the secondary ozonide groups and a series of the rearrangements of the oxygenated groups present in the compound. The reduction properties of C70ozopolymer were successfully assessed in the formation of silver nanoparticles from an acqueous solution of Ag+ions. [ABSTRACT FROM PUBLISHER]

Boron carbide B4C or, which is the same, B12C3, was neutron-bombarded at four different doses, namely at 1.09, 2.19, 3.28 and 4.38 × 1016n cm−2. The radiation-damage was studied by FT-IR, ESR (Electron Spin Resonance) and by DSC (Differential Scanning Calorimetry). It is shown that both FT-IR and ESR are useful techniques to monitor the radiation-damage level introduced in B12C3, with the ESR characterized by a higher sensitivity level than FT-IR. Thermal annealing of the neutron-treated B12C3from room temperature to 630°C permits to measure the release of the stored Wigner energy which was found comprised between 0.55 meV/atom at the lowest neutron dose to 2.29 meV/atom at the highest neutron dose employed. The values of Wigner energy measured on B12C3were comparable to those measured on fullerenes and graphite flakes at the same dose level. However, the thermal annealing of neutron-treated B12C3does not lead to the complete restoration of the pristine chemical structure before irradiation. [ABSTRACT FROM AUTHOR]

Single wall carbon nanohorn (SWCNH) were neutron-bombarded to a dose of 3.28 × 10n/cm. The Wigner or stored energy was determined by a differential scanning calorimeter and was found 5.49 J/g, 50 times higher than the Wigner energy measured on graphite flakes treated at the same neutron dose. The activation energy for the thermal annealing of the accumulated radiation damage in SWCNH was determined in the range 6.3-6.6 eV against a typical activation energy for the annealing of the radiation-damaged graphite which is in the range of 1.4-1.5 eV. Furthermore the stored energy in neutron-damaged SWCNH is released at 400-430 °C while the main peak in the neutron-damaged graphite occurs at 200-220 °C. The radiation damaged SWCNH were examined with FT-IR spectroscopy showing the formation of acetylenic and aliphatic moieties suggesting the aromatic C=C breakdown caused by the neutron bombardment. [ABSTRACT FROM AUTHOR]