Ksenia Викторовна Otopkova

Mrs. Ksenia Викторовна Otopkova

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 December 2024 in Energies
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EAEsipovich Anton
Esipovich Anton
EKEvgeny Kanakov
Evgeny Kanakov
TCTatyana A. Charykova
Tatyana A. Charykova
KOKsenia Викторовна Otopkova
Ksenia Викторовна Otopkova
MSMikhail A. Smirnov
Mikhail A. Smirnov
Artem S. BelousovArtem S. Belousov
Artem S. Belousov
This study is related to producing a set of fatty acid esters from different vegetable oils and C1–C12 alcohols. A total of 66 products were synthesized. The obtained esters were characterized by fatty acid composition, density, viscosity, saponification value, acid value, iodine value, low-temperature properties, and oxidative stability. It was established that the fatty acid composition, as well as alcohol, used has a significant impact on esters properties. Comparing physicochemical properties of fatty acid esters with existing standards and specifications, it was proposed to use esters for different industrial applications. In particular, rapeseed oil fatty acid methyl esters are an ideal candidate for application as biodiesel, while transesterification of soybean oil, sunflower oil, rapeseed oil, and coconut oil with higher alcohols led to products with promising properties as bio-lubricants. Castor oil alkyl esters could potentially be utilized as base oils due to their excellent viscosity and low-temperature properties.

30 December 2021 in Polymers
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ASAlexey Sivokhin
Alexey Sivokhin
DODmitry Orekhov
Dmitry Orekhov
OKOleg Kazantsev
Oleg Kazantsev
OSOlga Sivokhina
Olga Sivokhina
SOSergey Orekhov
Sergey Orekhov
RKRostislav Karpov
Rostislav Karpov
Amphiphilic random and diblock thermoresponsive oligo(ethylene glycol)-based (co)polymers were synthesized via photoiniferter polymerization under visible light using trithiocarbonate as a chain transfer agent. The effect of solvent, light intensity and wavelength on the rate of the process was investigated. It was shown that blue and green LED light could initiate RAFT polymerization of macromonomers without an exogenous initiator at room temperature, giving bottlebrush polymers with low dispersity at sufficiently high conversions achieved in 1–2 h. The pseudo-living mechanism of polymerization and high chain-end fidelity were confirmed by successful chain extension. Thermoresponsive properties of the copolymers in aqueous solutions were studied via turbidimetry and laser light scattering. Random copolymers of methoxy- and alkoxy oligo(ethylene glycol) methacrylates of a specified length formed unimolecular micelles in water with a hydrophobic core consisting of a polymer backbone and alkyl groups and a hydrophilic oligo(ethylene glycol) shell. In contrast, the diblock copolymer formed huge multimolecular micelles.

6 January 2023 in Catalysts
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EAEsipovich Anton
Esipovich Anton
EKEvgeny Kanakov
Evgeny Kanakov
TCTatyana A. Charykova
Tatyana A. Charykova
KOKsenia Викторовна Otopkova
Ksenia Викторовна Otopkova
The MIL-100(Cr), PW12@MIL-100(Cr) and PW4@MIL-100(Cr) catalysts were prepared and characterized through XRD, FTIR, BET, SEM, EDS and Raman spectroscopy. A comparison of the catalytic properties of the synthesized materials in the epoxidation of FAMEs with hydrogen peroxide was made. The PW4@MIL-100(Cr) catalyst exhibited the highest catalytic activity and provided a high selectivity for the formation of epoxides. The effects of the reaction temperature, catalyst loading, reaction time and FAME:hydrogen peroxide molar ratio on the reaction performance were investigated, and the optimal process conditions were determined. An epoxide yield of 73% with a selectivity of 77% could be obtained using PW4@MIL-100(Cr) after 4 h at 40 °C. The catalytic stability test showed that PW4@MIL-100(Cr) could be easily separated and reused without any treatment for at least five consecutive cycles without a loss of activity or selectivity.

1 December 2022 in Kinetics and Catalysis
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KOKsenia Викторовна Otopkova
Ksenia Викторовна Otopkova
AEA. L. Esipovich
A. L. Esipovich
EKE. A. Kanakov
E. A. Kanakov
TCT. A. Charykova
T. A. Charykova
VBV. E. Baydachenko
V. E. Baydachenko
TRT. A. Ryabova
T. A. Ryabova
The activity and stability of cation-exchange resins in fatty acid esterification with methyl alcohol have been studied. The cation-exchange resins have been characterized by IR spectroscopy, electron microscopy, and low-temperature nitrogen adsorption–desorption (BET method). It has been shown that, due to a developed surface and a larger pore volume, the reaction products are readily desorbed and thereby prevent the catalytic sites from blocking and the catalyst from losing activity. Of the studied cation-exchange resins, the best results have been obtained in the case of using the Lewatit MonoPlus SP 112 cation-exchange resin with a macroporous structure.

31 December 2023 in Polymers
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ASAlexey Sivokhin
Alexey Sivokhin
DODmitry Orekhov
Dmitry Orekhov
OKOleg Kazantsev
Oleg Kazantsev
KOKsenia Викторовна Otopkova
Ksenia Викторовна Otopkova
OSOlga Sivokhina
Olga Sivokhina
MCMaria Chubenko
Maria Chubenko
Herein, a series of ternary amphiphilic amide-containing bottlebrushes were synthesized by photoiniferter (PI-RAFT) polymerization of macromonomers in continuous-flow mode using trithiocarbonate as a chain transfer agent. Visible light-mediated polymerization of macromonomers under mild conditions enabled the preparation of thermoresponsive copolymers with low dispersity and high yields in a very short time, which is not typical for the classical reversible addition–fragmentation chain transfer process. Methoxy oligo(ethylene glycol) methacrylate and alkoxy(C12–C14) oligo(ethylene glycol) methacrylate were used as the basic monomers providing amphiphilic and thermoresponsive properties. The study investigated how modifying comonomers, acrylamide (AAm), methacrylamide (MAAm), and N-methylacrylamide (-MeAAm) affect the features of bottlebrush micelle formation, their critical micelle concentration, and loading capacity for pyrene, a hydrophobic drug model. The results showed that the process is scalable and can produce tens of grams of pure copolymer per day. The unmodified copolymer formed unimolecular micelles at temperatures below the LCST in aqueous solutions, as revealed by DLS and SLS data. The incorporation of AAm, MAAm, and N-MeAAm units resulted in an increase in micelle aggregation numbers. The resulting bottlebrushes formed uni- or bimolecular micelles at extremely low concentrations. These micelles possess a high capacity for loading pyrene, making them a promising choice for targeted drug delivery.

14 December 2024 in Polymers
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ASAlexey Sivokhin
Alexey Sivokhin
DODmitry Orekhov
Dmitry Orekhov
OKOleg Kazantsev
Oleg Kazantsev
KOKsenia Викторовна Otopkova
Ksenia Викторовна Otopkova
OSOlga Sivokhina
Olga Sivokhina
DBDmitry Barinov
Dmitry Barinov
Anionic thermo- and pH-responsive copolymers were synthesized by photoiniferter reversible addition–fragmentation chain transfer polymerization (PI-RAFT). The thermo-responsive properties were provided by oligo(ethylene glycol)-based macromonomer units containing hydrophilic and hydrophobic moieties. The pH-responsive properties were enabled by the addition of 5–20 mol% of strong (2-acrylamido-2-methylpropanesulfonic) and weak (methacrylic) acids. Upon initiation by visible light at 470 nm and in the absence of radical initiators, yields from the ternary copolymers reached 94% in 2.5 h when the process was carried out in continuous flow mode using 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid as a light-sensitive RAFT agent. The polymers were characterized using size exclusion chromatography, IR and NMR spectroscopy, and differential scanning calorimetry. The copolymers featured a sufficiently high molecular weight (93–146 kDa) consistent with theoretical values and satisfactory dispersities in the range of 1.18–1.45. The pH-responsive properties were studied in deionized water, saline, and buffer solutions. Dramatic differences in LCST behavior were observed in strong and weak acid-based polyelectrolytes. The introduction of sulfonic acid units, even in very small amounts, completely suppressed the LCST transition in deionized water while maintaining it in the saline and buffer solutions, with a negligible LCST dependence on the pH. In contrast, the incorporation of weak methacrylic acid demonstrated a pronounced pH dependence. The peculiarities of micelle formation in aqueous solutions were investigated and critical micelle concentrations and their ability to retain pyrene, a hydrophobic drug model, were determined. It was observed that anionic molecular brushes formed small micelles with aggregation numbers of 1–2 at concentrations in the order of 10−4 mg/mL. These micelles have a high ability to entrap pyrene, which makes them a promising tool for targeted drug delivery.