Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 1, pp. 50−53.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © D.G. Letenko, N.A. Charykov, V.A. Nikitin, K.N. Semenov, M.Yu. Matuzenko, V.A. Keskinov, E.G. Gruzinskaya, L.V. Tsvetkova,
2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 1, pp. 51−54.
INORGANIC SYNTHESIS AND INDUSTRIAL
Study of Aqueous Solutions of Fullerenol-d
by the Dynamic Light Scattering Method
D. G. Letenko
, N. A. Charykov
, V. A. Nikitin
, K. N. Semenov
, M. Yu. Matuzenko
V. A. Keskinov
, E. G. Gruzinskaya
, and L. V. Tsvetkova
St. Petersburg State University, St. Petersburg, Russia
Innovations at Leningrad Institutes and Enterprises Private Company, St. Petersburg, Russia
Northwestern State Technical University, St. Petersburg, Russia
St. Petersburg State Technological Institute, St. Petersburg, Russia
Received March 18, 2010
Abstract—Dynamic light scattering method was used to determine the average size of fullerenol-d associates
and the dependence of the electrokinetic ζ-potential on the concentration of aqueous solutions of fullerenol-d.
In [1–3], a technique for synthesis of fullerenol was
developed, fullerenol-d was identiﬁ ed by physicochemical
methods, the solubility and electrochemical and some
other properties of aqueous solutions were determined,
the composition of crystal hydrates was found, and the
molar electrical conductivities and apparent degree and
dissociation constant of fullerenol were calculated.
Our study is devoted to analysis of aqueous solutions
of fullerenol-d by the dynamic light scattering method.
The size distribution of fullerenol-d nanoparticles
in aqueous solutions with various concentrations was
determined by the dynamic light scattering method on
a Malvern Zetasizer instrument (Great Britain).
Typical size distributions of associates for aqueous
solutions of fullerenol-d are shown in Figs. 1a and
1b and are represented in the table. The fullerenol-d
concentration was widely varied: c
≈ 0.0137–18.3 g l
≈ 1.2 10–5–1.5 × 10
M). Unfortunately, more
concentrated fullerenol solutions and, in particular, that
≈ 0.17 M, are nontransparent and the method we
used to determine associate sizes becomes inapplicable.
It can be seen in Fig. 1 that, with increasing fullere-
nol-d concentration, the average diameter δ of fullere-
nol-d associates steadily grows, with a particular steep
rise in the size of associates observed on passing from
solution no. 4 to solution no. 5 (c
≈ 1.66 → 18 g l
δ ≈ 60 → 1100 nm.
The distribution of fullerenol-d associates over
linear sizes is rather characteristic (especially with the
complex composition of the mixture of these associates
taken into account). For example, the halfwidth of the
intensity peak, δ
≈ 1 rel. units, which corresponds to
more than an order-of-magnitude difference between
In all solutions (nos. 2–5), no unassociated particles
with diameters δ < 2 nm were found by the dynamic light
scattering method. This, in turn, means that even dilute
solutions of fullerenol-d are very strongly associated.
Figure 1b shows on a logarithmic scale how the
average size of associates of fullerenol-d depends on its
concentration, ln δ = f(ln c
). It can be seen that a rather
stable linear correlation is observed between these
functions in the logarithmic form. In other words, the
sought-for dependence δ(c
) can be expressed by a simple
relation: δ = αc
, where α and β are constants and
is the calculated diameter of a hydrated monomeric
molecule of fullerenol-d (at c
→ 0). Apparently, δ
= 0) in all cases.
Let us consider an evaluation calculation of δ
in more detail. It is apparent from general consider-