ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 8, pp. 1441–1445. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © B.B. Troitskii, V.N. Denisova, M.A. Novikova, M.A. Lopatin, L.V. Khokhlova, A.E. Golubev, 2008, published in Zhurnal Prikladnoi
Khimii, 2008, Vol. 81, No. 8, pp. 1365–1369.
Deposition of Thin Antireflection Coatings Based
on Mesoporous Silicon Dioxide by the Sol–Gel Method
in the Presence of Carbochain Polymers
and Statistical Copolymers
B. B. Troitskii, V. N. Denisova, M. A. Novikova, M. A. Lopatin,
L. V. Khokhlova, and A. E. Golubev
Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, Nizhni Novgorod, Russia
Received February 13, 2008
Abstract—Antireflection coatings with a low refractive index (1.25–1.34) were prepared from mesoporous
silicon dioxide by using carbochain polymers and statistical copolymers, instead of ionogenic and noionogenic
surfactants and amphiphilic block-copolymers in a sol–gel process. The optimal concentration of the organic
additive in the sol, at which a transparent film with the maximum antireflection effect is formed in the sol–gel
process followed by heating of a sample, was determined.
AND POLYMERIC MATERIALS
Thin-film antireflection interference coatings of
optical articles are widely used in optical and com-
mercial industries (antireflection coatings of display
screens, photodetectors, fiber-optic waveguides, etc.).
The principal limitation of thin-film antireflection
coatings is the impossibility of their deposition in a
vacuum onto large-size optical articles (large-aperture
optics based on optical articles fabricated from fused
silica and optical glass of various brands, nonlinear
water-soluble crystals, etc.).
In the general case, light is reflected at the inter-
face between two materials, e.g., silicate glass and air.
At a refractive index of glass n ≈ 1.51, about 8.6% of
light incident at a zero angle is reflected at two glass–
air interfaces. Theoretically, to minimize (to 0.0% in
the limiting case) the reflection of light with a wave-
length λ, glass should be coated with a transparent film
with a refractive index n
n ≈ 1.23 and optical
However, film-forming materials with such a low
refractive index are nonexistent in the nature. For ex-
ample, low refractive indices are observed for fluori-
nated compounds: magnesium difluoride (refractive
index 1.38) and Teflon (1.33), but the refractive indi-
ces of these substances substantially exceed the theo-
retical value of 1.23.
Therefore, multilayer coatings are widely used in
practice as antireflection coatings of optical articles:
two-layer, three-layer, four-layer, etc. . Various
types of multilayer antireflection coatings on silicate
glass are well known and have been considered in de-
tail, e.g., in US patents [2–5].
The practice of deposition of thin-film antireflec-
tion coatings onto optical articles employs vacuum
technologies  and the sol–gel method [6–10]. The
vacuum technologies use expensive equipment whose
cost increases with the size of optical articles. The di-
mensions of optical articles are limited by the size of
the vacuum chamber of deposition installations. The sol–
gel process is simpler experimentally and can be used
for deposition of coating onto large optical articles.
In 1992, scientists of Mobil Oil Corp. (USA)
made an important discovery in synthesis of new nano-
materials [11–13], they developed matrix synthesis of
mesoporous silicates and aluminosilicates. A group of
mesoporous materials, M41S (MCM-4, hexagonal
mesophase; MCM-48, cubic mesophase; MCM-50,
lamellar mesophase), with a regular, well-pronounced
system of nanosize structures was synthesized for the
first time by a sol–gel process in the presence of a cati-
onic surfactant. Owing to the comparatively simple
synthesis of new mesoporous materials and wide op-