II International Symposium on Carbon for Catalysis ABSTRACTS

OP-I-23
polyfunctional surface cover were found. It was established, that carrying out chemical
reactions on the diamond surface permit us to grow carbon atoms monolayers, for instance via
reactions: ≡C–Н + CCl 4 → ≡C–СН 2 Cl + HCl, ≡C–СН 2 Cl + CH 4 → ≡C–СН 2 CH 3 + HCl
By treatment of diamond powders with volatile halogenides (TiCl 4 , VCl 5 , CrCl 3 ) surface
metal-containing groups are formed that give us opportunities to perform surface synthesis for
further chemical modification.
Covalent grafting, i.e. surface interaction with various substances-modificators, is of
main interest in diamond surface chemical modification. This modification provides a basis
for fundamentally new spatial structures creation on its base. Native cover polyfunctionality
of ND prohibit from selective surface modification. As a result preliminary surface
monofunctionalization is needed. One of the most effective procedures of ND functional
cover unification consists in hydrogen stream treatment at 800 o C 5 hours. As a result of this
hydride group’s layer is formed on the diamond powder surface. This layer formation causes
the reduction of diamond surface reaction capacity. For its activation and electrophile center
creation it is subjected to halogenation. Photo- and thermochemical halogenation is
inconvenient because of free halogens and high temperatures utilization. Liquid phase
chlorination with SO 2 Cl 2 in benzene and chlorine in carbon tetrachloride in argon ambient is
more attractive. In the first case azobisisobutironitrile was used for initialization and in the
second – light irradiation. Both variants of chlorination yielded in completely full surface
hydrogen atoms substitution. However, hydrolytic instability of chlorinated diamond surface
should be considered. Interaction of chlorinated ND powder with butyllithium,
octadecyllithium and others resulted in alkyl groups grafting onto the diamond surface.
Phenyl groups were grafted to the surface via reaction with phenyllithium. Reaction of
chlorinated ND with sodium cyanide yielded in surface cyanide groups grafting.
Various physicochemical methods were used to characterize modified ND: IR- and
Auger-spectroscopy, XPS, EELS, NMR-H1, ESR, electron microscopy etc.
Method development and conditions discovering for monofunctional cover creation on
ND surface, on the one hand, can result in their more efficiently utilization, because ND
application is restrained by nonreproductivity and instability of their physicochemical
characteristics. On the other hand this may lead to creation of fundamentally new materials
for biomedical application (nanoparticles for directional drug carry in vivo, chromatographic
sorbents for HPLC etc.). In latter case sorbents based on modified porous ND cakes with
highly developed specific surface together with thin size distributed nanoporoues are
promising.
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