Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 10, pp. 1514−1518.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © A.B. Shishmakov, Yu.V. Mikushina, O.V. Koryakova, M.S. Valova, L.A. Petrov, 2012, published in Zhurnal Prikladnoi Khimii, 2012,
Vol. 85, No. 10, pp. 1577−1581.
AND INDUSTRIAL INORGANIC CHEMISTRY
Synthesis of Dispersed Silicon, Titanium, and Zirconium Dioxides
by Pyrolysis of Cellulose Inorganic Composites
A. B. Shishmakov, Yu. V. Mikushina, O. V. Koryakova, M. S. Valova, and L. A. Petrov
Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia
Received July 27, 2011
Abstract—The method of the synthesis of dispersed powders of silicon, titanium, and zirconium dioxides was
developed, including formation of cellulose inorganic composites by impregnation of pressed granules of powdered
cellulose with solutions of tetraethoxysilane and tetrabutoxy zirconium, hydrolysis of the organometallic constitu-
ent of the composite, pyrolysis of the cellulose matrix of the composite, and burning of its carbon constituent.
Recently, nanodispersed oxide materials with unique
properties attract much attention of researchers. The prop-
erties of these materials [reactivity, catalytic (photocata-
lytic) activity, etc.] depend on the method of preparation
and are determined by the size and shape of particles, and
by the surface structure.
Wide application of nanodispersed powders is largely
limited by the high cost of their production. Therefore,
the development of new energy-saving technologies of
the synthesis is underway.
One of the simplest methods for the synthesis of
dispersed material is “paper technology” including the
impregnation of a ﬁ lter paper or pure cellulose with a solu-
tion containing all the necessary components in dissolved
state and the following drying and burning of the “ﬁ lter.”
Cellulose ﬁ bers act as a reinforcing carrier in relation
to salt or organometallic components and prevent their
aggregation upon hydrolysis and drying. At the same
time, the cellulose matrix acts as a dispersant of the oxide
formed by the extensive gas evolution during its pyrolysis.
Therefore, powdered cellulose characterized by shorter
ﬁ ber length and greater homogeneity in comparison with
the conventional (ﬁ brous) cellulose is of greatest interest
for the synthesis of dispersed inorganic materials.
In the study, dispersed powders of SiO
were synthesized by pyrolysis of the organic matrix
of the cellulose inorganic composites and their physical
and chemical properties were determined.
Powdered cellulose (PC) was obtained by hydrolysis
of kraft pulp from the Baikal Pulp-and-Paper Combine
[TU (Technical Speciﬁ cations) OP 13-0279488-08-91]
in 2.5 N hydrochloric acid at 100°C. The hydrolysis was
performed for 2 hours. The resulting product was washed
on the ﬁ lter with distilled water to neutral pH value of the
aqueous extract. PC was squeezed on a vacuum ﬁ lter to
60 wt % moisture content and pressed in granules 5 mm
in diameter and 15 mm height. The granules were dried
at 100°C to constant weight. The total porosity of the PC
granules was l.2–1.6 cm
To prepare silicon dioxide powders [SiO
(P3), and SiO
(P4)], PC granules were im-
pregnated with tetraethoxysilane (TES) and methanol
solutions containing 100, 50, 20, and 10 vol % TES,
respectively, to saturation. The PC-TES samples were
placed in a desiccator over 10% aqueous ammonia and
kept there at 20°C for the TES hydrolysis. The PC-SiO
samples were dried at 90°C to constant weight. The
concentration of the inorganic component in the PC-SiO
samples was (wt %): PC-SiO
(P1) 24, PC-SiO
(P3) 9, and PC-SiO
(P4) 4. Noticeably, the TES
concentration and the SiO
content in the composite do
not correlate. This is evidently due to the fact that the po-
rosity of different heterogeneous granules is nonuniform
(its values are in the range 1.2–1.6 cm
). Then, the
pyrolysis of PCs was performed in a reactor equipped with