Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 2, pp. 214−219.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © I.N. Men’shikov, G.A. Emel’yanov, S.K. Kurlyand, N.G. Sukhodolov, A.N. Zhukov, 2013, published in Zhurnal Prikladnoi Khimii,
2013, Vol. 86, No. 2, pp. 232−238.
IN HETEROGENEOUS SYSTEMS
Surface Modiﬁ cation of Iron Particles with a Polyﬂ uorinated
: Effect of Solvent and Temperature
I. N. Men’shikov
, G. A. Emel’yanov
, S. K. Kurlyand
N. G. Sukhodolov
, and A. N. Zhukov
St. Petersburg State University, St. Petersburg, Russia
Lebedev Research Institute of Synthetic Rubber, St. Petersburg, Russia
Received January 24, 2013
Abstract—Adsorption of bis(2-chloro-3-oxaperﬂ uorobutyl) disulﬁ de from nonaqueous solutions onto the surface
of carbonyl iron particles was studied with the aim of modiﬁ cation of these particles. The adsorption parameters
were calculated using the Langmuir equation from the adsorption isotherms obtained in the interval 20–60°С.
With an increase in temperature and in the solvent afﬁ nity for the modifying agent, the limiting amounts of the
reagent that has interacted with the iron particle surface increase. This fact suggests the chemisorption nature
of the process. The products of the reaction of iron with the disulﬁ de can be desorbed from the particle surface.
An important problem in many modern technologies
such as preparation of magnetic ﬂ uids of new generation
[1, 2], of new types of radio-absorbing coatings
[3, 4], of elastic parts of structures controlled by
magnetic ﬁ eld [5, 6], etc., is ensuring aggregation and
sedimentation stability of metal dispersions in organic
solvents and liquid polymeric media. Of particular
interest is dispersing iron particles of various origins
in organic media, because iron exhibits high magnetic
characteristics and is readily available for setting up
large-scale production of magnetic composite materials.
However, iron particles tend to undergo uncontrollable
oxidation to oxides, which considerably deteriorates
their magnetic characteristics [1, 7].
To ensure stable characteristics of iron particles
and of composite materials containing such particles
in the course of storage or operation in aggressive
media at high temperatures, it is necessary to protect
the iron surface from corrosion. Simultaneously, it is
necessary to prevent agglomeration of such particles in
polymers resistant to heat and aggressive media, such as
ﬂ uoropolymers and polyﬂ uorosiloxanes exhibiting both
hydrophobic and oleophobic properties [8, 9]. Because
of poor solubility of ﬂ uoropolymers in solvents that well
wet inorganic ﬁ ller particles, it is difﬁ cult to introduce
such particles into ﬂ uoropolymers . To make the
ﬁ ller particles better compatible with the polymeric
matrix, their surface should be modiﬁ ed with substances
similar in chemical nature to the ﬂ uoropolymeric base.
In so doing, it is preferable to form covalent bonds of
ﬂ uorinated modiﬁ er molecules with the particle surface.
Modifying reagents are often added directly in the course
of particle formation. For example, graphite-coated
iron nanoparticles were prepared in an arc discharge
nanoparticles were obtained by sol–gel
method in the presence of oligomers with two terminal
perﬂ uoroalkyl groups (R
) ; iron particles stabilized
S radicals were prepared by joint pyrolysis of
iron pentacarbonyl at 250–350°С in the presence of
disulﬁ des with poly- and perﬂ uorinated radicals R
. It was shown that Fe–S–C covalent bond is
formed in this case on the iron surface. However, this
procedure has low productive capacity and requires
additional use of sophisticated equipment. Lee et al.
 suggested performing adsorption modiﬁ cation of
carbonyl iron nanoparticles immediately after their
preparation with a solution of hexadecanethiol in
ethanol under oxygen-free conditions, which enhances