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Saint Petersburg, Russia

Gordeev S.K.,Central Research Institute of Materials
Metal Science and Heat Treatment | Year: 2015

A method for fabricating high-porosity nanodiamond composites (NDC) from carbon fragments of two types, namely, particles of nanodiamond (with a mean size of 4 – 6 nm) and a nanosize graphite-like matrix bonding the particles into a single body is described. The biocompatibility of the NDC, the sorption of drugs by these materials and the biological activity of drug containers based on the NDC are determined. © 2015 Springer Science+Business Media New York Source

Belyaev S.P.,Saint Petersburg State University | Gordeev S.K.,Central Research Institute of Materials | Chekanov V.A.,RAS Petersburg Nuclear Physics Institute | Konopleva R.F.,RAS Petersburg Nuclear Physics Institute | And 4 more authors.
Physics of the Solid State | Year: 2014

The electrophysical properties of nanoporous carbon composites consisting of a nanometer-sized pyrolytic carbon matrix and nanodiamonds have been analyzed. It has been shown that the power-law dependence of the electrical resistivity on the thickness of the pyrolytic carbon layer D on a log-log scale has an inflection for D = 1 Å. It has been found that the temperature dependence of the electrical resistivity of the nanocomposite is described by an exponential function with an exponent of 1/4 for both unirradiated samples and samples irradiated with fast neutrons. This is characteristic of variable-range hopping conductivity in the case of strong localization in systems with semiconductor conductivity in the presence of a local disorder. With an increase in the neutron fluence, the electrical resistivity of the studied material changes very significantly (by several hundred percent) and nonmonotonically. This result is associated with the transformation of the structure of the graphite-like matrix and with possible graphite-diamond phase transitions. © 2014 Pleiades Publishing, Ltd. Source

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