共查询到10条相似文献,搜索用时 171 毫秒
1.
T. V. Tropin T. O. Kyrey O. A. Kyzyma A. V. Feoktistov M. V. Avdeev L. A. Bulavin L. Rosta V. L. Aksenov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(1):1-4
The transformation of the C60 fullerene cluster state into C60/N-methylpyrrolidone (NMP) solution after the addition of a nonpolar solvent (toluene, electric permittivity ?= 2.4) is studied. The results of ultraviolet-visible spectroscopy and small-angle neutron scattering measurements are used for comparison of the C60/NMP/toluene system with C60/NMP mixtures with a high-polar solvent (water, ? = 80). As to the observed reorganization of the cluster state, the C60/NMP/toluene system is similar to the C60/NMP/water system. This effect is explained by the formation of charge-transfer complexes in the initial C60/NMP solution. These complexes are thought to be soluble in both binary mixtures. The connection between the cluster-reorganization effect and solvatochromism is discussed. 相似文献
2.
A semi-empirical molecular dynamics model is developed. The central collisions of C60+C60 and He@C60+He@C60 at different incident energies are investigated based on this model. It is found that the dimer structures have been produced
at proper incident energies and these fullerene dimers could be formed by a self-assembly of C60 fullerene and He@C60. The He atom has a significant effect at higher incident energy and this embedded He atom can enhance the stability of the
dimer structure. 相似文献
3.
The quenching of the electronically excited states of various energy donors—Tb3+; 9,10-anthracene dibromide; and adamantanone—by C70 fullerene has been detected and analyzed. The quenching is characterized by anomalously high biomolecular quenching rate constants, which are obtained from the Stern-Volmer dependences of the energy-donor photoluminescence intensity on the concentration of the C70 molecules. It has been shown that the high efficiency of quenching by the C70 fullerene as compared to the C60 fullerene is due to the higher polarizability of the C70 molecule and large overlap integrals of the energy-donor photoluminescence spectra with the absorption spectrum of the C70 fullerene. 相似文献
4.
A. Leyderman E. I. Radovanova S. S. Sarkisov V. S. Vikhnin 《Physics of the Solid State》2005,47(11):2186-2195
The vibrational spectra of 2-cyclooctylamino-5-nitropyridine (COANP) solutions and the evolution of the spectra upon changing over from the solutions to solid-phase COANP are investigated. The bands observed in the spectra are assigned to the corresponding vibrational modes. The nature of the interaction of COANP with C60 and C70 fullerenes is elucidated by analyzing the transmission spectra of these compounds. No interaction of the COANP compound with C60 and C70 fullerenes is revealed under the studied conditions. It is assumed that the physical nature of this phenomenon can be associated with the formation of liquid-crystal clusters consisting of fullerene molecules. 相似文献
5.
E. A. Kyzyma M. O. Kuzmenko L. A. Bulavin V. I. Petrenko I. V. Mikheev M. A. Zabolotnyi M. Kubovcikova P. Kopcansky M. V. Korobov M. V. Avdeev V. L. Aksenov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2016,10(6):1125-1128
The C60 and C70 fullerene-cluster size distribution in aqueous solutions and a physiological medium is studied via dynamic light scattering. The initial aqueous solutions of fullerenes obtained via different methods are found to contain clusters with a characteristic size of about 100 nm. The additional aggregation of fullerenes is observed after their transfer into a physiological medium (0.9% NaCl) and is established to depend on the preparation method. The cluster-size distribution in a fullerene–pectic-acid mixture is found to vary in water and a physiological medium. The results reveal the need for additional studies of the structure and properties of C60 and C70 molecules, as well as their complexes with medicines, in a physiological medium for medical applications. 相似文献
6.
S. Duffe T. Irawan M. Bieletzki T. Richter B. Sieben C. Yin B. von Issendorff M. Moseler H. Hövel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(3):401-408
The low energy deposition of silver cluster cations with
561 (±5) atoms on a cold fullerene covered gold surface has
been studied both by scanning tunneling microscopy and molecular
dynamics simulation. The special properties of the
C60/Au(111) surface result in a noticeable fixation of the
clusters without a significant change of the cluster shape. Upon
heating to room temperature we observe a flattening or shrinking
of the cluster samples due to thermal activation. Similar changes were observed also for mass selected Ag clusters with other
sizes. For comparison
we also studied Ag islands of similar size, grown by low
temperature deposition of Ag atoms and subsequent annealing. A
completely different behavior is observed with much broader size
distributions and a qualitatively different response to
annealing. 相似文献
7.
Vasily Lavrentiev Jiri Vacik Hiroshi Naramoto Kazumasa Narumi 《Applied Physics A: Materials Science & Processing》2009,95(3):867-873
The structure transformation occurring in fullerene film under bombardment by 50 keV C60+ cluster ions is reported. The Raman spectra of the irradiated C60 films reveal a new peak rising at 1458 cm−1 with an increase in the ion fluence. This feature of the Raman spectra suggests linear polymerization of solid C60 induced by the cluster ion impacts. The aligned C60 polymeric chains composing about 5–10 fullerene molecules have been distinguished on the film surface after the high-fluence
irradiation using atomic force microscopy (AFM). The surface profiling analysis of the irradiated films has revealed pronounced
sputtering during the treatment. The obtained results indicate that the C60 polymerization occurs in a deep layer situated more than 40 nm below the film surface. The deep location of the C60 polymeric phase indirectly confirms the dominant role of shock waves in the detected C60 phase transformation. 相似文献
8.
N. P. Yevlampieva P. N. Lavrenko E. Yu. Melenevskaya L. V. Vinogradova E. I. Ryumtsev V. N. Zgonnik 《Physics of the Solid State》2002,44(3):563-566
The donor-acceptor complexes of the C60 fullerene with cycle-containing polymers, namely, poly(2,6-dimethyl-1,4-phenylene oxide) (PPhO) and poly(N-vinylpyrrolidone) (PVP), are studied. A comparative analysis of the hydrodynamic and electrooptical properties of the initial polymers and their complexes with C60 in solutions demonstrates that the C60 fullerene has a restructuring effect on the polymer macromolecule, thus decreasing the degree of asymmetry of the macromolecular structure. 相似文献
9.
T. V. Tropin N. Jargalan M. V. Avdeev O. A. Kyzyma D. Sangaa V. L. Aksenov 《Physics of the Solid State》2014,56(1):148-151
The aggregate growth in a C60/N-methylpyrrolidone (NMP) solution has been considered in the framework of the approach developed earlier for describing the cluster growth kinetics in fullerene polar solutions. The final cluster size distribution functions in model solutions have been estimated for two fullerene aggregation models including the influence of complex formation on the cluster growth using extrapolations of the characteristics of the cluster state and distribution parameters. Based on the obtained results, the model curves of small-angle neutron scattering have been calculated for a C60/NMP solution at various values of the model parameters. 相似文献
10.
M. S. Blanter V. V. Brazhkin V. P. Filonenko P. A. Borisova 《Bulletin of the Russian Academy of Sciences: Physics》2018,82(9):1096-1100
Phase transitions in two types of amorphous fullerene phases (C60–C70 (50/50) mixtures and an amorpous C70 fullerene phase) are studied via neutron diffraction at pressures of 2–8 GPa and temperatures of 200–1100°C. Fullerenes are amorphized by grinding in a ball mill and sintered under quasi-hydrostatic pressure in a toroidal-type chamber. Diffraction studies are performed ex situ. It is shown that the amorphous phase of fullerenes retains its structure at temperatures of 200–500°C, and amorphous graphite is formed at 800–1100°C with a subsequent transition to crystalline graphite. This process is slow in a mixture of fullerenes, compared to C70 fullerene. According to neutron diffraction data, the amorphous graphite formed from amorphous fullerene phases has anisotropy that is much weaker in a fullerene mixture. 相似文献