Effect of Fullerene С
on the Melting Point of p-Xylene
B. M. Ginzburg, S. Kh. Tabarov, and Sh. Tuichiev
Institute of Problems of Machine Science, Russian Academy of Sciences, St. Petersburg, Russia
Tajik National University, Dushanbe, Tajikistan
Received January 13, 2010
Abstract—The dependence of the p-xylene melting point on the concentration of fullerene С
dissolved in it
ISSN 1070-4272, Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 9, pp. 1671–1672. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © B.M. Ginzburg, S.Kh. Tabarov, Sh. Tuichiev, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 9, pp. 1575–1576.
The dependence of the melting point of an aromatic
solvent (p-xylene) on the concentration of fullerene
dissolved in it was determined in this work for the
first time. To determine the melting point, we placed a
graduated thermocouple connected to a highly sen-
sitive digital voltmeter in a solution to be tested
). The solution was cooled up to complete
freezing with the help of a cooler with liquid nitrogen.
Then the cooler was removed, and the frozen solution
began to heat spontaneously in room conditions.
Therewith the variation of temperature T in time t was
recorded. As usual, first a noticeable temperature
increase up to a certain value was observed and then, a
constant plateau from the beginning of a liquid phase
appearance up to the complete melting of the bulk
solution. The temperature corresponding to the plateau
was accepted as the melting point Т
. It is necessary
to note that the solution melting point essentially
depends on the external pressure, which was equal to
697 mm Hg in the experimental conditions.
(99.7% purity) obtained by the
Krätschmer–Huffman method  and chemically-pure
p-xylene after its repeated distillation were used. First
a mother solution with a previously known limiting
(%) was prepared. Then solutions
with intermediate concentrations were prepared by
dilution of this solution. Concentration of the solutions
was varied from с = 10
wt % up to concentrations
close to the concentration of a saturated fullerene
solution. The error in the determination of the lowest
concentrations was 1–2% and that for the highest
concentrations did not exceed 0.1–0.2% with a
The number of parallel measurements of the
melting point of samples with one definite
concentration was N = 10–30. The error of the mea-
surements ±∆t was found by the formula
∆t = Т
is a root-mean-square error in the results
of N measurements; Т, Student’s coefficient given for
various number of measurements and confidence
levels α in the tables [2, 3].
The relative error of the measurements (∆t/T
100% did not exceed 1% with a probability of 90%.
The linear function approximating the dependence of
the p-xylene melting point on fullerene concentration
was found by the least-squares method.
Experimental data described by Eq. (2) for
solutions in p-xylene are presented in the figure.
Dependence of the melting point of С
solutions in p-
xylene at T
(°С) on the fullerene concentration c (%).