2021, Boytsova, O. V., Markova, E. B., Simonov, V. N., Matison, N. L., Симонов, Валерий Николаевич

© 2021, Pleiades Publishing, Ltd.Abstract: The results of a study of the oscillations of microcantilevers (MCs) made of nanoporous anodic aluminum oxide and constituting the base of biochemical sensors are described. Finite-element modeling of an MC’s vibrations reveal the sources of resonances in the frequency spectrum that do not correspond to the cantilever’s oscillations and complicate the development of sensors. It is shown for the first time that such sources are resonances of vibrations of the base of the MC on the elastic layer of the compound used to attach the base to the substrate. Approximate relationships between the parameters of the MC, base, and compound layer are obtained, which ensure that only the working modes of MC vibrations are present in the spectrum. To ensure a clean spectrum, one of two conditions must be observed or a combination of both: a sufficiently rigid MC attachment to the substrate and a sufficiently small base size. Ensuring a clean spectrum is achieved regardless of the rigidity of the MC’s fastening as long as the base length does not exceed 0.6, 0.43, and 0.33 MC lengths, respectively, for the 3rd, 4th, and 5th harmonics of the MC’s working mode.

2019, Vlasov, D. A., Simonov, V. N., Симонов, Валерий Николаевич

© 2019, Springer Science+Business Media, LLC, part of Springer Nature.A method for measuring the concentration of chemicals in gases and liquids using sensors based on piezoelectric resonators with sensitive films of elastic polymers is considered. It is shown that the metrological characteristics of sensors with elastic films, the thickness of which is greater than the depth of penetration of oscillations of the resonator into the film, are determined by the vibrorheological properties of the film. Parameters of the acetone vapor sensor based on butyl acetate film are given.

2023, Simonov, V. N., Fomkin, A. A., Shkolin, A. V., Menshchikov, I. E., Симонов, Валерий Николаевич

2019, Fomkin, A. A., Vlasov, D. A., Grankina, T. Yu., Simonov, V. N., Симонов, Валерий Николаевич

The ratios between the film-sorbent parameters, sensitivity, and quartz sorption sensors' sensitivity threshold have been obtained and analyzed. It has been demonstrated that, for the sorption sensors of vapors and gases based on polymer films, there exists a range of optimal values of thickness caused by its effect on the elastic properties. For acetone vapor sensors with a film made of polymethyl methacrylate (PMMA), this range is equal to 0.4-0.6% of the sensor's plate thickness at the film deposition on both sides of the plate.

2023, Симонов, В. Н., Фомкин, А. А., Школин, А. В., Симонов, Валерий Николаевич

Изобретение относится к аналитическому приборостроению, в частности к области измерения концентрации веществ в газах или жидкостях и может применяться в промышленности, в быту, например, для предупреждения пожароопасных и взрывоопасных при утечках метана, или при повышении концентрации угарного газа, а также в медицине для определения заболеваний на ранней стадии путем выявления маркеров в выдыхаемом человеком воздухе, например, ацетона при сахарном диабете. Задачей изобретения является создание высокочувствительного сенсора, в котором бы сочеталось достоинство использования, адсорбентов с высокой крутизной изотермы в области малых концентраций веществ, с использованием высокочастотных пьезорезонаторов, а также пьезорезонаторов, на которые бы не влиял адсорбент, как дестабилизирующий частоту фактор. Технический результат предлагаемого изобретения заключается в снижении порога чувствительности сенсоров концентрации веществ. 1 з.п. ф-лы, 1 ил.

2024, Simonov, V. N., Fomkin, A. A., Shkolin, A. V., Menshchikov, I. E., Симонов, Валерий Николаевич

2022, Shkolin, A. V., Men'Shchikov, I. E., Khozina, E. V., Yakovlev, V. Y., Simonov, V. N., Симонов, Валерий Николаевич

© The temperature- and methane adsorption-induced deformations of microporous activated carbon Sorbonorit-4 were measured by in situ dilatometry over a wide range of temperatures and pressures. The thermal expansion coefficient of Sorbonorit-4 in vacuum increased linearly with temperature within a range of 293-573 K. Methane adsorption in Sorbonorit-4 induced its contraction at low pressures and temperatures or expansion at high temperatures throughout the entire pressure range. An inversion of the temperature dependence of adsorption-induced strain (AIS) of Sorbonorit-4 was found. At low pressures and temperatures below 300 K, the AIS isotherm showed a contraction of Sorbonorit-4; its magnitude and corresponding pressure interval decreased with temperature. At T > 300 K, the temperature rise was accompanied by an adsorption-induced expansion of Sorbonorit-4 up to 0.08% at 393 K. At high pressures, the expansion decreased from 0.45 to 0.13% when the temperature increased from 213 to 393 K. The AIS of Sorbonorit-4 and differential isosteric heat of adsorption presented as functions of methane uptake changed within the same intervals of adsorption values, reflecting variations in the state of adsorbed molecules determined by contributions from the adsorbate-adsorbent and adsorbate-adsorbate interactions. The obtained results are essential for practical use of carbon adsorbents for natural gas storage.

2022, Simonov, V. N., Artamonova, S. D., Fomkin, A. A., Shkolin, A. V., Menshchikov, I. E., Симонов, Валерий Николаевич

2019, Markova, E. B., Cherednichenko, A. G., Serov, Yu. M., Odintsova, M. V., Simonov, V. N., Симонов, Валерий Николаевич

Features of propane conversion for selective olefin production in the presence of nanofibrous aerogel materials have been studied. The effect of modification of aerogel alumina with titania and silica on the catalytic activity and the olefin selectivity in propane conversion at atmospheric pressure has been shown. Low-temperature nitrogen adsorption has revealed that these catalysts have a developed specific surface area of about 300 m(2)/g; water vapor adsorption at 293 K has shown that materials of this type contain 0.2-0.6 mmol/g of acid sites. X-ray diffraction analysis and transmission electron microscopy have revealed that the synthesized materials are an amorphous aerogel with tangled fibers with a thickness of similar to 6 nm.