Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 8, pp. 1394−1398.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
Yu.G. Tselishchev, V.A. Val’tsifer, V.N. Strel’nikov, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 8, pp. 1288−1293.
A Study of Structuring of a Microdisperse Filler
in Oligomer Formulations in a Flow
Yu. G. Tselishchev, V. A. Val’tsifer, and V. N. Strel’nikov
Institute of Technical Chemistry, Branch, Russian Academy of Sciences, Perm, Russia
Received March 23, 2010
Abstract—Method for analysis of the evolution of microstructural formations of a disperse ﬁ ller in transparent
oligomer formulations in a ﬂ ow is suggested. The method enables studies of microstructural changes in formulations
in a wide range of viscosities, temperatures of the medium, shear stresses, and ﬁ ller dispersities.
Use of micro- and nanodisperse components as
ﬁ llers for oligomer composite materials necessitates
determination of modes of their mixing with a viscous
binder. It is known that disperse formulations are
structurally and optically inhomogeneous [1–6], and,
therefore, optical methods have been used to examine
the rheological properties of polymeric formulations
and the effect of mixing modes on disintegration of
agglomerates of ﬁ ller particles, their distribution, and
structuring in a formulation.
Various methods of study are known, based on the
dependence of the optical properties of substances on
their composition and structure [7–9]. However, these
methods can be used to study materials in an immobile
state or those subjected to only periodic mechanical
impacts. Meanwhile, motion or displacement of both the
separate components of a formulation, e.g., in particle
sedimentation in a viscous ﬂ ow, and the formulation itself
in, in particular, its ﬂ ow strongly affect the appearance
and evolution of structural formations and, accordingly,
the modiﬁ cation of various properties of formulations,
including their optical properties. These changes are
largely due to viscous properties of formulations and
to the dispersity, properties, and volume ﬁ lling of the
The goal of our study was to develop a method for
study of the evolution of microstructural formations
in a disperse ﬁ ller in transparent viscous oligomer
formulations in a ﬂ ow.
The theoretical foundations we used in developing
the method are the Rayleigh and Heller dependences
describing the light scattering by spherical nonabsorbing
particles. Light beams directed to a disperse system are
incident on the surface of particles, reﬂ ected and refracted
at various angles, absorbed by particles and the binder,
and emerge from the system in different directions.
Apparently, the intensity of beams emerging from the
system is lower than the original intensity. In this case,
the absorption in the system is the stronger, the more
pronounced its structural inhomogeneity, i.e., the higher
the dispersity and concentration of the solid phase.
As an index characterizing the ability of a system
to scatter light we use the proportionality coefﬁ cient τ
equal to the ratio between the intensities of scattered
) and incident (I
) light, related to a unit length of
a sample. According to the Rayleigh equation, the
intensity of light scattered at an angle is given by
is the constant including invariable parameters
in the Rayleigh equation; ν, number of particles in
a unit volume; V
, volume of particles; λ, wavelength
of incident light; and c, mass concentration of particles.
Using dependence (1) to determine the intensities of
light scattered by two formulations with equal volume
concentration V of particles, but different particle sizes