ISSN 1061-933X, Colloid Journal, 2018, Vol. 80, No. 3, pp. 346–348. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © M.E. Kartseva, O.V. Dement’eva, A.V. Zaitseva, V.M. Rudoy, 2018, published in Kolloidnyi Zhurnal, 2018, Vol. 80, No. 3, pp. 357–359.
Templateless Synthesis of Organosilica Nanotoroids and Creation
of Core/Shell Plasmonic Structures Thereon
M. E. Kartseva, O. V. Dement’eva*, A. V. Zaitseva, and V. M. Rudoy
Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, 119071 Russia
Received December 27, 2017
Abstract—It has been shown for the first time that nanosized organosilica toroids can be formed via hydrolytic
condensation of (γ-mercaptopropyl)trimethoxysilane in an alkaline medium. It has been found that such
toroids may be used as “nuclei” for the synthesis of plasmonic composite nanoparticles with a core/shell
Silica-based toroidal structures are of substantial
interest for the development of new optical and
optomechanical devices (including lasers with a low
threshold of generation [1, 2]). At present, photoli-
thography is the main method for the formation of
such structures . However, this method is rather
complex technically and cannot be used to create
objects with lateral sizes of less than 100 nm .
Therefore, the development of a method for the
colloid chemical synthesis of silica toroids is an urgent
problem from both fundamental and applied points of
It should be emphasized that, in spite of the sub-
stantial progress that has been made in the synthesis of
anisotropic silica and organosilica particles, works
devoted to the creation of toroidal structures are, so
far, very scarcer [5–7]. The formation of organosilica
toroids (OSTs) via template sol–gel synthesis [5, 6] is
mainly considered in these works. Moreover, along
with a micellar template, compounds capable of addi-
tional structuring action are introduced into reaction
In this communication, we first demonstrate the
feasibility of templateless sol–gel synthesis of OSTs
with the use of (γ-mercaptopropyl)trimethoxysilane
(MPTMS) as a precursor.
The experiments were performed as follows.
MPTMS (10 μL) and a 28% NH
OH solution (400–
800 μL) (both of ACS Reagent grade, Sigma-Aldrich)
were added to a plastic tube containing deionized
water (10 mL). The reaction mixture was sonicated,
stirred for 24 h, and stored for 1–7 days.
According to the data of high-resolution transmis-
sion electron microscopy (HRTEM) and atomic force
microscopy (AFM), hydrolytic condensation of
MPTMS under these conditions results in the forma-
tion of OSTs with a rather high yield.
Figures 1 and 2 show images of particles resulting
from 48-h synthesis. It can be seen that the lateral sizes
(the distance from the center of the generating circle to
the rotation axis) of the toroids vary in a wide range
from ≈30 nm to several microns. Therewith, large
toroids are easier to deform, obviously because of low
rigidity. At the same time, the diameter of the generat-
ing surface of OSTs is almost independent of their size
and equal to nearly 30 nm.
LETTER TO THE EDITOR
Fig. 1. HRTEM image of OSTs.