2021, Akopdzhanov, A. G., Shimanovsky, N. L., Belogorlov, A. A., Bortnikova, S. A., Белогорлов, Антон Анатольевич, Бортникова, Светлана Алексеевна

© 2021, Springer Science+Business Media, LLC, part of Springer Nature.The possibilities of using porous silicon nanostructured containers as drug carriers are considered. The main design principles of the nanocontainers and the possibility of using pore surface modification to achieve the optimal regimes of drug loading and controlled in vivo drug release are formulated. Results from studies devoted to the application of porous silica containers are presented. The main prospects and research tasks in this field are related to reducing the object size, increasing the biocompatibility, increasing the drug loading volume, and achieving the optimal drug release kinetics.

2022, Yurkov, A. L., Malakho, A. P., Ivanov, A. V., Chernova, E. A., Belogorlov, A. A., Avdeev, V. V., Белогорлов, Антон Анатольевич

The study is aimed to deepen the understanding of the interrelation between density, open and closed porosity as well as gas permeability of compressed graphite foils with a density ranging from 0.5 to 1.8 g·cm−3 designed especially for sealing applications. The pore structure of the graphite foil samples is experimentally measured by several complementary methods: low-temperature N2 adsorption, method of saturation with liquids (hydrostatic weighting), mercury porosimetry, and helium leak detection for gas permeability measurement. A comparative study of the porosity obtained by mercury porosimetry and by saturation with water and isopropanol, made it possible to propose a reliable express method for determining and controlling the porosity of dense graphite foil. It was found that the characteristic pore size and open porosity of graphite foil decreases with increasing its density from 0.5 to 1.8 g·cm−3 leading to a decrease in helium gas permeability of the foils. An average capillary diameter, the number of capillaries and their effective cross-sectional area was calculated on the basis of the dependence of helium gas permeability on foil density and gas pressure. The obtained data were applied for describing the pore structure of the graphite foils with low density and explanation of their low gas permeability. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

2020, Belogorlov, A. A., Borman, V. D., Bortnikova, S. A., Byrkin, V. A., Tronin, I. V., Tronin, V. N., Белогорлов, Антон Анатольевич, Бортникова, Светлана Алексеевна, Быркин, Виктор Александрович, Тронин, Иван Владимирович

© 2020 Published under licence by IOP Publishing Ltd.In the present paper we present the results of experimental and theoretical studies of intrusion-extrusion and relaxation of non-wetting liquid in three Fluka porous media. New data on hysteresis of intrusion-extrusion and dependence of the degree of filling of a porous body on time in the process of extrusion were obtained experimentally. It has been established that in all the conducted experiments the liquid extrusion took place in two stages: at the first stage of fast relaxation the characteristic time of outflow is several seconds, at the second stage of slow relaxation the characteristic time is several hundred seconds. The experimental data obtained are described in the theoretical model [1]. For the studied porous media, the existence at the initial moment of time of local states with short leakage times (a few seconds or less) and states with large leakage times (hundreds of seconds) was established. Porous bodies in which the coexistence of fast and slow states at the initial moment of time is established are investigated for the first time.

2020, Bortnikova, S. A., Belogorlov, A. A., Borman, V. D., Byrkin, V. A., Бортникова, Светлана Алексеевна, Белогорлов, Антон Анатольевич, Быркин, Виктор Александрович

© 2020 Published under licence by IOP Publishing Ltd.In the present work the results of experimental studies of relaxation of non-wetting liquid captured by the system of nanopores of Fluka 100 C8+C1 medium are presented. New data on dependence of filling degree on time in the process of outflow at partial initial filling have been obtained. In all the experiments carried out, fluid outflow was carried out in two stages: in the first stage of fast relaxation the characteristic time of outflow is a few seconds, in the second stage of slow relaxation the characteristic time can reach 104 seconds. It was found that "fast"states exist at any initial filling, and the degree of these states increases both with increasing temperature and with increasing initial filling of nanoporous medium with non-wetting liquid.

2021, Neimark, A. V., Belogorlov, A. A., Borman, V. D., Khlistunov, I. A., Tronin, V. N., Белогорлов, Антон Анатольевич, Хлистунов, Игорь Андреевич

© 2021 Elsevier Inc.Hypothesis: Suspensions of nanoporous particles in non-wetting fluids (lyophobic nanoporous suspensions, LPNPS) are explored as energy absorbing materials for shock absorbers, bumpers, and energy storage. Upon application of pressure, the non-wetting fluid invades the pores transforming the impact energy into the interfacial energy that can be stored and released on demand. Experiments: Here, we present a comprehensive experimental study of the dynamics of LPNPS compression within a wide range of shock impact energy for three types of mesoporous materials (Libersorb 23, Polysorb-1, and Silochrome-1.5) with water and Wood alloy as non-wetting fluids. Findings: Three different regimes of the LPNPS compression-expansion cycle in response to the shock impact are distinguished as the impact energy increases: without fluid penetration into the pores, with partial penetration, and with complete pore filling. In two latter regimes, the suspension compressibility in the process of rapid compression increases by 2–4 decimal decades. This giant effect is associated with the onset of penetration of the non-wetting fluid into the nanopores upon achievement of a certain threshold pressure. The dynamic threshold pressure exceeds the threshold pressure of quasistatic intrusion and does not depends on the impact pressure, temperature, and suspension composition. A dynamic model of suspension compression is suggested that allows to separate the effects of the fluid intrusion into the pores and the elastic deformation of the system.

2021, Borman, V. D., Belogorlov, A. A., Tronin, I. V., Белогорлов, Антон Анатольевич, Тронин, Иван Владимирович

© 2021, Pleiades Publishing, Inc.A new mechanism has been proposed for the cooperative transport of a nonwetting liquid in a nanoporous medium. The description of transport is based on the theory of critical dynamics of multiscale phenomena in atomic systems. Transport is described as a time-multiscale process of interaction of a fluctuating filling–escape mode, macroscopic spontaneous filling mode, and filling mode caused by the critical pressure of compression of a dynamic percolation transition. The model is based on the solution of the system of kinetic equations for the distribution function of accessible and filled pores, which allows calculating macroscopic quantities describing processes at various time scales. A case where macroscopic transport modes are developed simultaneously in two different time scales is considered. A “nanoscopic” model of filling of nanopores under the development of the spontaneous mode taking into account the conservation of the volume of the suspension at the equality of rates of development of the modes at different time scales has been proposed. The predicted time dependences of the flux and volume of filled pores correspond to dissipationless transport in the system of nanopores. Theoretical dependences describe known and new experimental data. Unusual dynamic properties correspond to the properties of systems with positive feedback.

2020, Khlistunov, I. A., Belogorlov, A. A., Borman, V. D., Хлистунов, Игорь Андреевич, Белогорлов, Антон Анатольевич

© 2020 Published under licence by IOP Publishing Ltd.In this work critical constant filling pressure conditions for systems "nanoporous medium-non-wetting liquid"under impact were studied. To determine the conditions influencing on the occurrence of a constant filling pressure, a series of impact experiments have been carried out on four porous media with distilled water as non-wetting liquid. On the basis of the obtained experimental data for the systems under investigation, a method for determining the flow rate of liquid in the pores was developed and its values for the systems under investigation in a given range of impact energies were determined. It is shown that the liquid flow rate in the pores is one of the key parameters determining the presence of a constant critical filling pressure. It was also found that in the investigated energy range the liquid flow rate increases and goes to limit with increasing impact energy.

2021, Mingalev, P. G., Bortnikova, S. A., Belogorlov, A. A., Бортникова, Светлана Алексеевна, Белогорлов, Антон Анатольевич

© 2021, Pleiades Publishing, Ltd.This work presents the results of studying hydrophobized silica gel Fluka 100 C8 + C1 with additional chemical surface modification by single-link alkylsilane. The material is studied by low-temperature nitrogen sorption and liquid porometry, including additional liquid porometry methods. The results of studying the system without additional modification are also presented. All results are presented for three temperatures: 20, 40, and 60°C. It is shown that additional chemical modification allows an increase in the fraction of the nonwetting liquid flowing from the pores with increasing temperature while maintaining a significant proportion of nonwetting liquid that has not outflowed under normal conditions. The obtained results show that, by additional modification, it is possible to control the process of the time relaxation of a nonwetting liquid in a nanoporous medium.

2021, Shimanovsky, N. L., Belogorlov, A. A., Khrebtov, D. S., Bortnikova, S. A., Белогорлов, Антон Анатольевич, Бортникова, Светлана Алексеевна

© 2021, Springer Science+Business Media, LLC, part of Springer Nature.The outflow kinetics of aqueous solutions of n-propanol as model liquids (drug solutions) from hydrophobic nanoporous silica gel 60 C8 was studied. The solution surface tension was shown to influence the hysteresis of intrusion-extrusion pressures and outflow rate. The use of substances changing the surface tension of the injected solution, in particular doxorubicin, allows one to control the relaxation/release of doxorubicin molecules in/from the focus of the disorder at the optimum rate. The obtained results can be used to create drug delivery systems based on silicon nanoparticles.

2020, Bortnikova, S. A., Belogorlov, A. A., Borman, V. D., Бортникова, Светлана Алексеевна, Белогорлов, Антон Анатольевич

© 2020 Published under licence by IOP Publishing Ltd.It is known that for the most nanoporous medium-non-wetting liquid systems are observed non-outflow phenomenon. It is shown that this phenomenon may depend on many factors, one of which is a waiting time. The observed anomalously slow relaxation (non-wetting liquid outflow) caused by formation of strongly interacting states of liquid clusters in pores. Previously was shown that relaxation of such states can occur due to relaxation of metastable local configurations of filled and empty pores. In the present work the relaxation of non-wetting liquid (water) dispersed in disordered nanoporous medium (hydrophobic silica gel Libersorb 23) for 6 and 9° C is considered. The pore size distribution functions of captured liquid for 9° C are obtained. Some local configurations for 6 and 9° C are analyzed and their lifetimes are defined.