ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 1, pp. 13−17. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © Yu.G. Khabarov, I.M. Babkin, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 1, pp. 15−20.
INORGANIC SYNTHESIS AND INDUSTRIAL
Effect of Magnetic Field and Temperature in Synthesis
of a Magnetoactive Compound Based on Iron(II) Sulfate
Yu. G. Khabarov and I. M. Babkin
Northern (Arctic) Federal University, Novgorodskii pr. 34, Arkhangelsk, 163000 Russia
Received December 23, 2014
Abstract—Effect of a magnetic ﬁ eld and temperature on how the magnetic activity is formed in a synthesis of a
nanosize magnetoactive compound is considered. Raising the temperature in the synthesis of the magnetoactive
compound results in a substantial rise in the magnetic activity at the beginning of the synthesis and accelerates
the sedimentation and peptization of the deposit. The magnetic ﬁ eld makes the magnetic activity approximately
30–50% higher and results in that a more compact deposit is formed, with the peptization rate not affected.
Nanosize particles of magnetoactive compounds
(MACs), to which belong particles of magnetite (Fe
or ferrites of composition MFe
, are the dispersed
phase of the colloid system, a magnetic ﬂ uid (MF). As the
dispersion medium of the MF serves water or an organic
solvent (e.g., kerosene), with stabilizers (e.g., oleic acid)
used to preclude the adhesion of particles.
Magnetic ﬂ uids are unique in that they simultaneously
combine the ﬂ owability and ability to interact with a
magnetic ﬁ eld [1, 2], which predetermines the wide
spectrum of their practical application.
Two methods, dispersion and condensation, are
presently used to synthesize magnetic ﬂ uids.
The typical condensation method of MF synthesis is
based on the reaction involving cations of di- and trivalent
↓ + 4H
Ultradispersed magnetite particles are formed if the
condensation is performed at a Fe
cation ratio of
2 : 1 under permanent agitation and heating to 70°C.
To reduce the temperature to 25–40°C, ammonium
hydroxide is used for condensation [6–9].
Methods for obtaining a magnetoactive compound of
the magnetite type on the basis of only an iron(II) salt
are used less frequently. An oxidizing agent is necessary
in this case. For example, V.G. Belikov an co-authors
suggested a method in which magnetite is formed at
55–60°C in 1 h from iron(II) carbonate preliminarily
precipitated from a solution of an iron(II) salt .
In a number of studies [11, 12], the role of stabilizers
of a magnetic ﬂ uid based on magnetite produced by a
prolonged thermal treatment of di- and trivalent iron salts
was played, instead of the commonly used oleic acid, by
technical-grade lignosulfonates (TGLS).
TGLSs modiﬁ ed by the nitrosation reaction acquire an
unusual property: their use in syntheses of MACs from
iron(II) sulfate can yield MACs as a nanosize colloid
produced via peptization of the sediment originally
formed in condensation [13, 14].
Lignosulfonates are formed in cooking of cellulose
half-products with sulfuric acid and its salts and have
markedly different properties, depending on the cooking
pH, with the nitrosation reaction also occurring in
different ways. Nitrosated lignosulfonates formed in the
classical sulﬁ te cooking exhibit the maximum peptizing
capacity for magnetite particles formed as a result of
condensation from an iron(II) sulfate solution. The size
of particles formed in synthesis of a magnetoactive
compound with the use of nitrosated lignosulfonic acids
is 19–32 nm .