ISSN 1070-4272, Russian Journal of Applied Chemistry, 2016, Vol. 89, No. 5, pp. 690í696. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © S.V. Dyachenko, M.A. Vaseshenkova, K.D. Martinson, I.A. Cherepkova, A.I. Zhernovoi, 2016, published in Zhurnal Prikladnoi Khimii,
2016, Vol. 89, No. 5, pp. 553í559.
INORGANIC SYNTHESIS AND INDUSTRIAL
Synthesis and Properties of Magnetic Fluids Produced
on the Basis of Magnetite Particles
S. V. Dyachenko, M. A. Vaseshenkova, K. D. Martinson,
I. A. Cherepkova, and A. I. Zhernovoi
St. Petersburg State Technological Institute (Technical University), Moskovskii pr. 26, St. Petersburg, 190013 Russia
Received April 20, 2016
Abstract—Magnetic ﬂ uids based on magnetite synthesized by the chemical condensation method at temperatures
of 25, 40, 60, and 80°C were obtained and studied. Magnetite particles were examined by X-ray phase and X-ray
ﬂ uorescence analyses and electron microscopy. The average size of the coherent scattering region of magnetite
particles was 13–17 nm, depending on the synthesis temperature. Magnetic ﬂ uids were synthesized from magnetite
particles obtained at 25 and 80°C, with water and octane serving as carrier ﬂ uids. The NMR method was used to
determine the saturation magnetization and average magnetic moment of the particles: for water-based magnetic
ﬂ uids, 2100 A m
and 5.7 × 10
at magnetite particle synthesis temperature of 25°C and 3670 A m
4.6 × 10
at magnetite particle synthesis temperature of 80°C; for octane-based magnetic ﬂ uids, 2250 A m
and 4.1 × 10
at magnetite particle synthesis temperature of 25°C.
The magnetic ﬂ uid is a colloid solution composed of
a carrier ﬂ uid and stabilized ferromagnetic particles .
Magnetic ﬂ uids are most frequently stabilized with sur-
factants adsorbed in the course of synthesis on the surface
of the particles and thereby preclude their aggregation and
sedimentation. The application areas of magnetic ﬂ uids
are rather diverse [2, 3]. For example, these ﬂ uids can be
used in engineering as sealants, lubricating and cooling
materials and heat carriers, and components of sensors
, and can serve for separation of nonmagnetic materi-
als. In medicine, magnetic ﬂ uids are used as transporters
of medicinal preparations [5, 6] and contrast substances
 and serve for creating labels in cells and for separating
cells and removing malignant cells by the hyperthermia
method [7, 8]. Despite the wide potential application ﬁ eld,
the ﬂ uids have not gained wide recognition because of
the complicated preparation and introduction into produc-
tion, compared with alternative substances and articles.
Preparation of magnetic ﬂ uids is an unconventional task
for researchers and manufacturers. There exist a multitude
of synthesis methods whose details are, as a rule, inacces-
sible and considered commercially sensitive information.
In this study, we synthesized magnetic ﬂ uids and
made a physicochemical analysis of their properties.
The synthesis was carried out with magnetite particles
produced by the chemical condensation method ﬁ rst
described in . This technique belongs to a variety of
liquid-phase methods, is one of the simplest, and does
not require speciﬁ c conditions and laboratory equipment,
and, therefore, it has gained wide acceptance in the United
States, Japan, Ukraine, and Russia. It is noteworthy
that the analytical methods include NMR spectroscopy,
which is not widely employed in the research practice
and in industrial production for monitoring of magnetic
properties, but yields results coinciding with the classical
notions of physics, which could not be obtained by other
methods. This circumstance opens up new prospects for
application of magnetic ﬂ uids.
Preparation of magnetic particles. Magnetite particles
served as the starting magnetic material for preparation
of magnetic ﬂ uids. The magnetite particles were synthe-