Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 7, pp. 1318−1323.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
V.I. Shadrina, I.A. Bashmakov, E.A. Gracheva, V.E. Agabekov, F.N. Kaputskii, 2010, published in Zhurnal Prikladnoi Khimii, 2010,
Vol. 83, No. 7, pp. 1212−1216.
AND POLYMERIC MATERIALS
Inﬂ uence of the Conditions of Formation of Nitrocellulose
Honeycomb-Structure Films on Their Morphology
V. I. Shadrina
, I. A. Bashmakov
, E. A. Gracheva
, V. E. Agabekov
, and F. N. Kaputskii
Institute of Chemistry of New Materials, National Academy of Sciences of Belarus, Minsk, Belarus
Research Institute of Physicochemical Problems, Belarussian State University, Minsk, Belarus
Received October 6, 2010
Abstract—Physicochemical features of formation and morphology of submicron honeycomb-structure
nitrocellulose ﬁ lms with hexagonal cell symmetry were examined.
Microstructured honeycomb-like polymer ﬁ lms
are of interest for such ﬁ elds as microelectronics,
biotechnology, and optics, in development of new
catalytic systems, sensor devices, and membranes for
various functional purposes [1–3].
Honeycomb-structure ﬁ lms with uniform cell size,
based on macromolecular compounds, can be prepared by
such methods as lithography and microcontact printing
. They are based on transfer of a deﬁ nite pattern
from one support to another using a phototemplate or a
master . The main advantage of this approach is good
reproducibility of the results. However, the process
is time-consuming, requires sophisticated expensive
equipment and a template, and in the case of lithography
is also power-consuming, which restricts its application.
It is more feasible to prepare honeycomb-structure ﬁ lms
by “self-organization” of water microdroplets under the
action of humid air on a liquid polymer ﬁ lm formed on
the water surface [1–3].
It is known that honeycomb-structure ﬁ lms with
micrometer cell size can be prepared by breathing onto
a liquid polymer ﬁ lms. Such patterns are termed breathing
ﬁ gures. However, the breathing method, when applied
to a number of polymers, including nitrocellulose (NC)
, though being simple, is characterized by certain
indeﬁ niteness and cannot be standardized. It is still
poorly understood how the history of the NC sample
(degree of polymerization, polydispersity of the initial
cellulose material, etc.) affects the shape, size, and
uniformity of pores in NC microhoneycomb-structure
In this study we examined how the molecular-weight
characteristics of NC, solution concentration, aqueous
phase temperature, and ratio of the volume of the drop
of the initial polymer solution to the area of the water
surface affect the formation and morphology of NC
honeycomb-structure ﬁ lms. The ﬁ lms were prepared
in a specially assembled installation simulating the
breathing method .
Nitrocellulose was isolated from collodion (NC
solution in an alcohol–ether mixture) or prepared
by nitration of microcrystalline cellulose [5, 6].
Microcrystalline cellulose was prepared by hydrolysis
of hydrated cellulose to the “limiting” degree of
polymerization (LDP) in 10% aqueous nitric acid
solution with reﬂ uxing for 30 min.
The polydispersity of NC samples was evaluated
by turbidimetric titration. For this purpose, NC was
dissolved in acetone (0.04 g/100 ml) and titrated
by adding a precipitant (distilled water) in 0.1-ml
portions until a constant optical density was attained
. The optical density was measured with a KFK-3
photocolorimeter at a wavelength of 540 nm.
The average molecular weight of NC was estimated
by viscometry . The viscosity was measured with an