1070-4272/05/7810-1591 + 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 10, 2005, pp. 1591!1595. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 10, 2005,
Original Russian Text Copyright + 2005 by Stavitskaya, Goba, Tomashevskaya, Kartel’.
AND ION-EXCHANGE PROCESSES
Development of Procedures for Synthesis of Carbon Materials
with Molecular-Sieve Properties
S. S. Stavitskaya, V. E. Goba, A. N. Tomashevskaya, and N. T. Kartel’
Institute of Sorption and Endoecology Problems, National Academy of Sciences of Ukraine, Kiev, Ukraine
Received December 30, 2004; in final form, April 2005
Abstract-New methods for synthesis of uniformly porous carbon materials with sieve properties and small
apparent density from phenol-formaldehyde resins were developed; the optimal conditions of their synthesis
were determined. New types of finely dispersed carbon powders were prepared using various treatment
procedures at different stages; the structural and sorption properties of the resulting materials were studied.
Synthesis of sorption-active carbon materials with
developed pores of molecular size is being intensively
studied using both common procedures [e.g., progres-
sive activation, which increases the content of micro-
and mesopores in the polydispersed system of carbon
material (CMs)] and new methods, which yield carbon
particles (nanotubes) with controlled size of pore
openings , which may exhibit a molecular-sieve
Solution of various scientific and technological
problems (such as sorption and separation of macro-
molecular compounds and preparation of chemosor-
bents, carbon-based conducting materials, electronic
nanodevices, and molecular sensors) requires develop-
ment of new special-purpose materials. Therefore,
a search for new ultramicroporous carbon materials
a topical task.
In this study, we examined the procedures for pre-
paring new carbon materials with sieve properties:
low-density nanosize carbon powders.
Carbon molecular sieves can be prepared from
various carbon-containing materials: lignite and coal
(including anthracite), lignin, wood, peat, synthetic
and natural polymers, and other organic compounds.
Carbonization and activation of these materials under
appropriate conditions yield sorbents with a rather
uniform pore structure containing micropores whose
size is comparable with that of adsorbed molecules.
For example, such low-density materials were pre-
pared by carbonization of polymeric compounds pre-
treated by various procedures, including modification
with inorganic additives . In particular, carbon
sorbents with exactly the prescribed structure were
prepared using NaCl  and silicon  additives.
Oxidation and activation of carbon sorbents as in-
fluenced by additives of alkali metal (including potas-
sium) salts were studied in . In the present study,
we examined various procedures for synthesis of car-
bon sorbents with molecular-sieve properties (required
porosity) from phenol-formaldehyde resins, using
a finely dispersed KCl additive.
The samples were prepared by two procedures.
(1) The initial polymer was boiled in a saturated
aqueous solution of potassium chloride for 2 h.
The sample was stored in solution for 8 h at room
temperature, recovered from the solution, and dried
at 120oC. Then, the sample was annealed in a furnace
in an argon atmosphere at 200oC for 1 h, at 600oC
for 0.5 h, and at 1000oC for 0.5 h. After thermal
treatment, KCl was washed out with hot distilled
(2) The initial resin was treated with saturated KCl
solution for 2.5 h at room temperature, the solution
was decanted, and the sample was dried at 120oC and
annealed at 600oC in an argon atmosphere for 1.5 h.
After thermal treatment, KCl was washed out with hot
The parameters of the pore structure determined
from benzene sorption at various P/P
the calculated apparent densities d of the resulting