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Prof. Vladimir Volkov
A.V. Topchiev Institute of Petrochemical synthesis

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0 Gas Separation
0 Membrane
0 hollow fibers
0 membrane reactor
0 Membrane Bioreactors

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Journal article
Published: 09 June 2021 in Polymers
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The influence of hyper-crosslinked polystyrene (HCPS) MacronetTM MN200 on the gas transport properties and aging of the highly permeable glassy polymer poly(1-trimethylsilyl-1-propyne) (PTMSP) was studied and analyzed in detail. The gas transport characteristics of dense PTMSP membranes containing 0–10.0 wt % HCPS were studied. It was shown that the introduction of a small amount of HCPS into the PTMSP matrix led to a 50–60% increase of the permeability coefficients of the material for light gases (N2, O2, CO2) and slowed down the deterioration of polymer transport properties over time. The lowest reduction in gas permeability coefficients (50–57%) was found for PTMSP containing HCPS 5.0 wt % after annealing at 100 °C for 300 h. It was found that HCPS sorbed residues of tantalum-based polymerization catalyst from PTMSP. In order to investigate the influence of catalysts on transport and physical properties of PTMSP, we purified the latter from the polymerization catalyst by addition of 5 wt % HCPS into polymer/chloroform solution. It was shown that sorption on HCPS allowed for almost complete removal of tantalum compounds from PTMSP. The membrane made of PTMSP purified by HCPS demonstrated more stable transport characteristics compared to the membrane made of the initial polymer. HCPS has a complex effect on the aging process of PTMSP. The introduction of HCPS into the polymer matrix not only slowed down the physical aging of PTMSP, but also reduced chemical aging due to removal of active reagents.

ACS Style

Georgy Golubev; Danila Bakhtin; Sergey Makaev; Ilya Borisov; Alexey Volkov. Hybrid Microporous Polymeric Materials with Outstanding Permeability and Increased Gas Transport Stability: PTMSP Aging Prevention by Sorption of the Polymerization Catalyst on HCPS. Polymers 2021, 13, 1922 .

AMA Style

Georgy Golubev, Danila Bakhtin, Sergey Makaev, Ilya Borisov, Alexey Volkov. Hybrid Microporous Polymeric Materials with Outstanding Permeability and Increased Gas Transport Stability: PTMSP Aging Prevention by Sorption of the Polymerization Catalyst on HCPS. Polymers. 2021; 13 (12):1922.

Chicago/Turabian Style

Georgy Golubev; Danila Bakhtin; Sergey Makaev; Ilya Borisov; Alexey Volkov. 2021. "Hybrid Microporous Polymeric Materials with Outstanding Permeability and Increased Gas Transport Stability: PTMSP Aging Prevention by Sorption of the Polymerization Catalyst on HCPS." Polymers 13, no. 12: 1922.

Journal article
Published: 27 May 2021 in Membranes
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This article describes a new technique for the preparation of hollow fiber (HF) membrane samples using an automatic manipulator unit. The manipulator uses a syringe needle to form a HF of a given geometry. The needle in automatic mode is sequentially immersed, first into the polymer solution and then into the coagulation bath. The possibility of using a manipulator to obtain HF samples was studied on the known polysulfone (PSf)/N-methylpyrrolidone (NMP)/pore-forming additive system. A series of HF membrane samples were made within 29 h from twelve 1 mL PSf casting solutions. This was 15 times faster than obtaining samples of HF membranes at the multifunctional research laboratory facility. From the point of view of the consumption of the components of the casting solution, the use of the manipulator was 30 times more economical, and the consumption of water for precipitation and washing was 8000 times less. The developed method made it possible to study samples of HF by scanning electron microscopy (SEM), ultrafiltration, and evaluate its mechanical properties without spinning the membranes. Using the new technique, the optimal composition of the casting solution for the wet spinning of HF PSf membranes was selected during two weeks. Thus, the manipulator makes it possible to significantly reduce the time of the new membrane preparation, reduce the volume of used polymer, and thus makes it promising to study expensive or new membrane materials.

ACS Style

Tatyana Anokhina; Alisa Raeva; Sergey Makaev; Ilya Borisov; Vladimir Vasilevsky; Alexey Volkov. Express Method of Preparation of Hollow Fiber Membrane Samples for Spinning Solution Optimization: Polysulfone as Example. Membranes 2021, 11, 396 .

AMA Style

Tatyana Anokhina, Alisa Raeva, Sergey Makaev, Ilya Borisov, Vladimir Vasilevsky, Alexey Volkov. Express Method of Preparation of Hollow Fiber Membrane Samples for Spinning Solution Optimization: Polysulfone as Example. Membranes. 2021; 11 (6):396.

Chicago/Turabian Style

Tatyana Anokhina; Alisa Raeva; Sergey Makaev; Ilya Borisov; Vladimir Vasilevsky; Alexey Volkov. 2021. "Express Method of Preparation of Hollow Fiber Membrane Samples for Spinning Solution Optimization: Polysulfone as Example." Membranes 11, no. 6: 396.

Journal article
Published: 02 May 2021 in Fibers
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This study deals with the investigation of the phase state of the polymer systems from polysulfone (PSF) with the addition of polyethylene glycol (PEG-400, Mn = 400 g·mol−1) and polyvinylpyrrolidone (PVP K-30, Mn = 40,000 g·mol−1) in N,N-dimethylacetamide (DMA), which feature lower critical solution temperatures (LCSTs). A fragment of the phase state diagram of the system PSF —PEG-400—PVP K-30—DMA was experimentally constructed in the following range of component concentrations: PSF 20–24 wt.%, PEG-400—35–38 wt.% and PVP—0–8 wt.%. It has been established that PVP addition substantially reduces the phase separation temperature down to 50–60 °C. Based on the obtained phase diagrams, a method for preparation of highly permeable hollow fiber membranes from PSF, which involves the processing of the dope solution at a temperature close to the LCST and the temperature of the bore fluid above the LCST, was proposed. Hollow fiber membranes with pure water flux of 1200 L·m−2·h−1 and a sponge-like macrovoid-free structure were obtained via LCST-thermally induced phase separation by free fall spinning technique.

ACS Style

Tatiana Plisko; Alexandr Bildyukevich; Liang Zhao; Weiqing Huang; Vladimir Volkov; Zuohua Huang. Formation of Polysulfone Hollow Fiber Membranes Using the Systems with Lower Critical Solution Temperature. Fibers 2021, 9, 28 .

AMA Style

Tatiana Plisko, Alexandr Bildyukevich, Liang Zhao, Weiqing Huang, Vladimir Volkov, Zuohua Huang. Formation of Polysulfone Hollow Fiber Membranes Using the Systems with Lower Critical Solution Temperature. Fibers. 2021; 9 (5):28.

Chicago/Turabian Style

Tatiana Plisko; Alexandr Bildyukevich; Liang Zhao; Weiqing Huang; Vladimir Volkov; Zuohua Huang. 2021. "Formation of Polysulfone Hollow Fiber Membranes Using the Systems with Lower Critical Solution Temperature." Fibers 9, no. 5: 28.

Review
Published: 01 April 2021 in Petroleum Chemistry
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This review provides an analysis of modern process technologies for carbon dioxide removal from various gas mixtures (such as natural gas or hydrocarbon conversion gases in ammonia and syngas production facilities), as well as from flue gases generated during the combustion of carbon-containing feedstocks in power plants. The review also discusses various approaches to improve absorption/desorption processes, both in terms of extending the range of practicable amine solvents and the prospects for the implementation of a new equipment type, namely membrane contactors based on hollow fiber membranes or ceramic tubular elements. Finally, the paper describes a process configuration for the decarbonation of rich amine solvents at ≤90°C using 12% monoethanolamine (MEA) solutions to prevent the solvent from thermo-oxidative degradation.

ACS Style

E. G. Novitskii; S. D. Bazhenov; A. V. Volkov. Optimization of Methods for Purification of Gas Mixtures to Remove Carbon Dioxide (A Review). Petroleum Chemistry 2021, 61, 407 -423.

AMA Style

E. G. Novitskii, S. D. Bazhenov, A. V. Volkov. Optimization of Methods for Purification of Gas Mixtures to Remove Carbon Dioxide (A Review). Petroleum Chemistry. 2021; 61 (4):407-423.

Chicago/Turabian Style

E. G. Novitskii; S. D. Bazhenov; A. V. Volkov. 2021. "Optimization of Methods for Purification of Gas Mixtures to Remove Carbon Dioxide (A Review)." Petroleum Chemistry 61, no. 4: 407-423.

Journal article
Published: 25 March 2021 in Polymers
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In this study, the nanoscale transformation of the polylactic-co-glycolic acid (PLGA) internal structure, before and after its supercritical carbon dioxide (sc-CO2) swelling and plasticization, followed by foaming after a CO2 pressure drop, was studied by small-angle X-ray scattering (SAXS) for the first time. A comparative analysis of the internal structure data and porosity measurements for PLGA scaffolds, produced by sc-CO2 processing, on a scale ranging from 0.02 to 1000 μm, was performed by SAXS, helium pycnometry (HP), mercury intrusion porosimetry (MIP) and both “lab-source” and synchrotron X-ray microtomography (micro-CT). This approach opens up possibilities for the wide-scale evaluation, computer modeling, and prediction of the physical and mechanical properties of PLGA scaffolds, as well as their biodegradation behavior in the body. Hence, this study targets optimizing the process parameters of PLGA scaffold fabrication for specific biomedical applications.

ACS Style

Alexey Buzmakov; Andrey Dunaev; Yuriy Krivonosov; Denis Zolotov; Irina Dyachkova; Larisa Krotova; Vladimir Volkov; Andrew Bodey; Victor Asadchikov; Vladimir Popov. Wide-Ranging Multitool Study of Structure and Porosity of PLGA Scaffolds for Tissue Engineering. Polymers 2021, 13, 1021 .

AMA Style

Alexey Buzmakov, Andrey Dunaev, Yuriy Krivonosov, Denis Zolotov, Irina Dyachkova, Larisa Krotova, Vladimir Volkov, Andrew Bodey, Victor Asadchikov, Vladimir Popov. Wide-Ranging Multitool Study of Structure and Porosity of PLGA Scaffolds for Tissue Engineering. Polymers. 2021; 13 (7):1021.

Chicago/Turabian Style

Alexey Buzmakov; Andrey Dunaev; Yuriy Krivonosov; Denis Zolotov; Irina Dyachkova; Larisa Krotova; Vladimir Volkov; Andrew Bodey; Victor Asadchikov; Vladimir Popov. 2021. "Wide-Ranging Multitool Study of Structure and Porosity of PLGA Scaffolds for Tissue Engineering." Polymers 13, no. 7: 1021.

Journal article
Published: 28 February 2021 in Membranes
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Lithium-rich geothermal waters are considered as an alternative source, and further concentration of lithium is required for its effective recovery. In this work, we have simulated a three-stage lithium recovery process including the brine softening by precipitation Ca2+/Mg2+ cations with sodium carbonate (calculated in PHREEQC), followed by an integrated system consisting of membrane distillation unit (water evaporation), crystallizer (NaCl precipitation), and membrane extraction (Li+ recovery), which was simulated in Simulink/MATLAB. It was shown that the deterioration of membrane performance in time due to scaling/fouling plays a critical role in the performance of the system resulting in the dramatic increase of the replaced membrane modules by a factor of 5. Low cost membranes are required. The process simulation based on the experimental and literature data on the high salinity solutions with the membrane distillation revealed that the specific productivity can be achieved in the range of 9.9–880 g (Li+) per square meter of membranes in the module used before its replacement. The increase of energy efficiency is needed. The mass-flow-rate of saline solution circulated to the crystallizer was set at its almost minimum value as 6.5 kg/min to enable its successful operation at the given parameters of the membrane distillation unit. In other words, the operation of the integrated system having 140 kg of saline solution in the loop and a membrane module of 2.5 m2 for concentration of lithium presence from 0.11 up to 2.3 g/kg would be associated with the circulation of about of 259 tons of saline solution per month between the distillation unit (60 °C) and the crystallizer (15 °C) to yield of up to 1.4 kg of lithium ions. The comprehensive summary and discussion are presented in the conclusions section.

ACS Style

Denis Kalmykov; Sergey Makaev; Georgy Golubev; Ilia Eremeev; Vladimir Vasilevsky; Jianfeng Song; Tao He; Alexey Volkov. Operation of Three-Stage Process of Lithium Recovery from Geothermal Brine: Simulation. Membranes 2021, 11, 175 .

AMA Style

Denis Kalmykov, Sergey Makaev, Georgy Golubev, Ilia Eremeev, Vladimir Vasilevsky, Jianfeng Song, Tao He, Alexey Volkov. Operation of Three-Stage Process of Lithium Recovery from Geothermal Brine: Simulation. Membranes. 2021; 11 (3):175.

Chicago/Turabian Style

Denis Kalmykov; Sergey Makaev; Georgy Golubev; Ilia Eremeev; Vladimir Vasilevsky; Jianfeng Song; Tao He; Alexey Volkov. 2021. "Operation of Three-Stage Process of Lithium Recovery from Geothermal Brine: Simulation." Membranes 11, no. 3: 175.

Journal article
Published: 14 December 2020 in Membranes
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The mitigation of the physical aging of thin-film composite (TFC) poly[1-trimethylsilyl-1-propyne] (PTMSP) membranes was studied via the simultaneous application of a polymer-selective layer crosslinking and mixed-matrix membrane approach. For the first time, a recently developed highly porous activated carbon material (infrared (IR) pyrolyzed poly[acrylonitrile] (PAN) or IR-PAN-a) was investigated as an additive to a PTMSP-selective layer for the reduction of aging in TFC membranes. The total electric energy spent on the IR irradiation treatment of IR-PAN-a particles was twice lower than conventional heating. The flat-sheet porous microfiltration membrane MFFK-1 was used as a support, and the crosslinked PTMSP/PEI loaded with a porous filler was applied as a selective layer (0.8–1.8 µm thick) to the TFC membranes. The initial IR-PAN-a sample was additionally milled to obtain a milled IR-PAN-aM sample with a monomodal particle size distribution of 500–800 nm. It was shown that IR-PAN-a, as a filler material with a high surface area and pore volume (2450 m2/g and 1.06 cm3/g, respectively) and a well-developed sponge-like structure, leads to the increase of the N2, O2, and CO2 permeance of PTMSP-based hybrid membrane material and the decrease of the aging of PTMSP. The simultaneous effect of crosslinking and the addition of a highly porous filler essentially improved the aging behavior of PTMSP-based TFC membranes. The monomodal and narrow particle size distribution of highly porous activated IR-pyrolyzed PAN is a key factor for the production of TFC membranes with reduced aging. The highest stability was achieved by the addition of a milled IR-PAN-aM sample (10 wt%). TFC membrane permeance was 6300 GPU (30% of initial permeance) after 11,000 h of aging at ambient laboratory conditions.

ACS Style

Danila Bakhtin; Stepan Bazhenov; Victoria Polevaya; Evgenia Grushevenko; Sergey Makaev; Galina Karpacheva; Vladimir Volkov; Alexey Volkov. Aging of Thin-Film Composite Membranes Based on Crosslinked PTMSP/PEI Loaded with Highly Porous Carbon Nanoparticles of Infrared Pyrolyzed Polyacrylonitrile. Membranes 2020, 10, 419 .

AMA Style

Danila Bakhtin, Stepan Bazhenov, Victoria Polevaya, Evgenia Grushevenko, Sergey Makaev, Galina Karpacheva, Vladimir Volkov, Alexey Volkov. Aging of Thin-Film Composite Membranes Based on Crosslinked PTMSP/PEI Loaded with Highly Porous Carbon Nanoparticles of Infrared Pyrolyzed Polyacrylonitrile. Membranes. 2020; 10 (12):419.

Chicago/Turabian Style

Danila Bakhtin; Stepan Bazhenov; Victoria Polevaya; Evgenia Grushevenko; Sergey Makaev; Galina Karpacheva; Vladimir Volkov; Alexey Volkov. 2020. "Aging of Thin-Film Composite Membranes Based on Crosslinked PTMSP/PEI Loaded with Highly Porous Carbon Nanoparticles of Infrared Pyrolyzed Polyacrylonitrile." Membranes 10, no. 12: 419.

Originalpaper
Published: 27 November 2020 in Petroleum Chemistry
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The review summarizes the accumulated scientific results on the separation of mixtures of organic solvents by pervaporation and reverse osmosis. It has been shown that the pervaporation process makes it possible to achieve generally higher selectivity as compared to the reverse osmosis process; however, a number of developments, such as membranes from polyketone or PIM-1, make it possible to effectively separate components with similar molecular weights. Such membranes allow the main advantage of reverse osmosis—lower energy consumption due to the absence of phase transitions—to be gained. It is noted that with the use of reverse osmosis membranes, the highest efficiency can be achieved in the case of separation of mixtures of organic liquids that differ significantly in their polarity, a process that is especially important for the regeneration of polar extractants in the petrochemical industry.

ACS Style

A. A. Yushkin; G. S. Golubev; I. A. Podtynnikov; I. L. Borisov; V. V. Volkov. Separation of Mixtures of Polar and Nonpolar Organic Liquids by Pervaporation and Nanofiltration (Review). Petroleum Chemistry 2020, 60, 1317 -1327.

AMA Style

A. A. Yushkin, G. S. Golubev, I. A. Podtynnikov, I. L. Borisov, V. V. Volkov. Separation of Mixtures of Polar and Nonpolar Organic Liquids by Pervaporation and Nanofiltration (Review). Petroleum Chemistry. 2020; 60 (11):1317-1327.

Chicago/Turabian Style

A. A. Yushkin; G. S. Golubev; I. A. Podtynnikov; I. L. Borisov; V. V. Volkov. 2020. "Separation of Mixtures of Polar and Nonpolar Organic Liquids by Pervaporation and Nanofiltration (Review)." Petroleum Chemistry 60, no. 11: 1317-1327.

Journal article
Published: 25 November 2020 in Polymers
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In this work, the precipitation of a thin layer of a polymer solution was proposed to imitate the process of asymmetric membrane formation by a non-solvent induced phase separation (NIPS) technique. The phase inversion within the thin (2∙h∙bar. To summarize, the precipitation of polymer solution within the thin layer can be considered a prompt technique and a powerful tool for fast screening and optimization of the complex composition of casting solutions using its small quantity. Furthermore, the prediction of membrane morphology can be done without casting the membrane, further post-treatment procedures, and scanning electron microscopy (SEM) analysis.

ACS Style

Tatiana Anokhina; Ilya Borisov; Alexey Yushkin; Gleb Vaganov; Andrey Didenko; Alexey Volkov. Phase Separation within a Thin Layer of Polymer Solution as Prompt Technique to Predict Membrane Morphology and Transport Properties. Polymers 2020, 12, 2785 .

AMA Style

Tatiana Anokhina, Ilya Borisov, Alexey Yushkin, Gleb Vaganov, Andrey Didenko, Alexey Volkov. Phase Separation within a Thin Layer of Polymer Solution as Prompt Technique to Predict Membrane Morphology and Transport Properties. Polymers. 2020; 12 (12):2785.

Chicago/Turabian Style

Tatiana Anokhina; Ilya Borisov; Alexey Yushkin; Gleb Vaganov; Andrey Didenko; Alexey Volkov. 2020. "Phase Separation within a Thin Layer of Polymer Solution as Prompt Technique to Predict Membrane Morphology and Transport Properties." Polymers 12, no. 12: 2785.

Journal article
Published: 19 November 2020 in Membranes
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This work was focused on the study of hypochlorite treatment on the pore size distribution of membranes. To this end, ultrafiltration membranes from a polysulfone/polyvinylpyrrolidone blend with a sponge-like structure were fabricated and exposed to hypochlorite solutions with different active chlorine concentrations for 4 h at ambient temperature. Liquid–liquid displacement and scanning electron microscopy were employed to study the limiting and surface pores, respectively. After treatment with 50 ppm hypochlorite solution at pH = 7.2, a five-fold increase in water permeance up to 1400 L/(m2·h·bar) was observed, accompanied by a 40% increase in the limiting pore sizes and almost a three-fold increase in the porosity. After 5000 ppm treatment at pH = 11.5, a 40% rise in the maximum limiting pore size and almost a two-fold increase in the porosity and permeance was observed, whereas the mean pore size was constant. Apparently, changes in the membrane structure at pH = 11.5 were connected with polyvinylpyrrolidone (PVP) degradation and wash-out, whereas at lower pH and despite lower active chlorine concentration, this process was coupled with polysulfone (PSf) destruction and removal.

ACS Style

George Dibrov; George Kagramanov; Vladislav Sudin; Evgenia Grushevenko; Alexey Yushkin; Alexey Volkov. Influence of Sodium Hypochlorite Treatment on Pore Size Distribution of Polysulfone/Polyvinylpyrrolidone Membranes. Membranes 2020, 10, 356 .

AMA Style

George Dibrov, George Kagramanov, Vladislav Sudin, Evgenia Grushevenko, Alexey Yushkin, Alexey Volkov. Influence of Sodium Hypochlorite Treatment on Pore Size Distribution of Polysulfone/Polyvinylpyrrolidone Membranes. Membranes. 2020; 10 (11):356.

Chicago/Turabian Style

George Dibrov; George Kagramanov; Vladislav Sudin; Evgenia Grushevenko; Alexey Yushkin; Alexey Volkov. 2020. "Influence of Sodium Hypochlorite Treatment on Pore Size Distribution of Polysulfone/Polyvinylpyrrolidone Membranes." Membranes 10, no. 11: 356.

Journal article
Published: 20 July 2020 in Journal of Membrane Science
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Infrared (IR) irradiation was applied to prepare thermally rearranged (TR) and carbon molecular sieve (CMS) membranes based on the polymer precursor of HPI-HD5. The effects of the IR treatment conditions such as temperature, time, and environment on the thermal conversion of TR and CMS membranes were investigated for the first time. The membranes subjected to the IR furnace exhibited the same changes of the chemical structure and comparable gas transport behaviors as the membranes treated in the electric furnace. Surprisingly, the maximum treating temperature and processing time were reduced by ~100 °C and a factor of ~20, respectively, in the IR furnace due to the energy-intensive heat radiation and instant temperature control. By replacing the electric furnace with the IR furnace, energy savings by a factor of ~10 were obtained at the same thermal conversion rate and consequently, the overall productivity was improved by more than a factor of 100. The applicability and advantages of efficient IR irradiation on TR and CMS membrane fabrication were confirmed in this study.

ACS Style

Won Hee Lee; Joon Yong Bae; Alexey Yushkin; Mikhail Efimov; Jun Tae Jung; Alexey Volkov; Young Moo Lee. Energy and time efficient infrared (IR) irradiation treatment for preparing thermally rearranged (TR) and carbon molecular sieve (CMS) membranes for gas separation. Journal of Membrane Science 2020, 613, 118477 .

AMA Style

Won Hee Lee, Joon Yong Bae, Alexey Yushkin, Mikhail Efimov, Jun Tae Jung, Alexey Volkov, Young Moo Lee. Energy and time efficient infrared (IR) irradiation treatment for preparing thermally rearranged (TR) and carbon molecular sieve (CMS) membranes for gas separation. Journal of Membrane Science. 2020; 613 ():118477.

Chicago/Turabian Style

Won Hee Lee; Joon Yong Bae; Alexey Yushkin; Mikhail Efimov; Jun Tae Jung; Alexey Volkov; Young Moo Lee. 2020. "Energy and time efficient infrared (IR) irradiation treatment for preparing thermally rearranged (TR) and carbon molecular sieve (CMS) membranes for gas separation." Journal of Membrane Science 613, no. : 118477.

Original contribution
Published: 22 June 2020 in Colloid and Polymer Science
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Vinylidene fluoride (VDF)/tetrafluoroethylene (TFE) 94/6 copolymer films obtained by low-temperature crystallization from acetone solution and by melt-crystallization under high pressure were studied. As shown in the X-ray diffraction patterns, β- and γ- phases coexist in the sample crystallized from a solution. At melt-crystallization, a number of γ-crystals decrease and spherulitic supramolecular structure is formed. It is accompanied by a decrease of the amorphous phase density in the intra- and inter-spherulite regions, which leads to an increase in the glass transition temperature. Differential scanning calorimetry data indicate a smaller fraction of the amorphous phase for the sample crystallized from the melt. At the same time, the relaxation strength of the mobility in the amorphous phase in this sample is higher. This contradiction is explained by the increased ratio of isomers in planar zigzag conformation, as shown by IR spectroscopy.

ACS Style

V. V. Kochervniskii; V. A. Astakhov; S. A. Bedin; I. A. Malyshkina; N. A. Shmakova; A. A. Korlyukov; M. I. Buzin; V. V. Volkov. Peculiarities of structure and dielectric relaxation in ferroelectric vinylidene fluoride-tetrafluoroethylene copolymer at different crystallization conditions. Colloid and Polymer Science 2020, 298, 1169 -1178.

AMA Style

V. V. Kochervniskii, V. A. Astakhov, S. A. Bedin, I. A. Malyshkina, N. A. Shmakova, A. A. Korlyukov, M. I. Buzin, V. V. Volkov. Peculiarities of structure and dielectric relaxation in ferroelectric vinylidene fluoride-tetrafluoroethylene copolymer at different crystallization conditions. Colloid and Polymer Science. 2020; 298 (9):1169-1178.

Chicago/Turabian Style

V. V. Kochervniskii; V. A. Astakhov; S. A. Bedin; I. A. Malyshkina; N. A. Shmakova; A. A. Korlyukov; M. I. Buzin; V. V. Volkov. 2020. "Peculiarities of structure and dielectric relaxation in ferroelectric vinylidene fluoride-tetrafluoroethylene copolymer at different crystallization conditions." Colloid and Polymer Science 298, no. 9: 1169-1178.

Journal article
Published: 03 June 2020 in Polymers
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Polynorbornenes represent a fruitful class of polymers for structure–property study. Recently, vinyl-addition polynorbornenes bearing side groups of different natures were observed to exhibit excellent gas permeation ability, along with attractive C4H10/CH4 and CO2/N2 separation selectivities. However, to date, the gas transport properties of fluorinated addition polynorbornenes have not been reported. Herein, we synthesized addition polynorbornene with fluoroorganic substituents and executed a study on the gas transport properties of the polymer for the first time. A norbornene-type monomer with a C6F5 group, 3-pentafluorophenyl-exo-tricyclononene-7, was successfully involved in addition polymerization, resulting in soluble, high-molecular-weight products obtained in good or high yields. By varying the monomer concentration and monomer/catalyst ratio, it was possible to reach Mw values of (2.93–4.35) × 105. The molecular structure was confirmed by NMR and FTIR analysis. The contact angle with distilled water revealed the hydrophobic nature of the synthesized polymer as expected due to the presence of fluoroorganic side groups. A study of the permeability of various gases (He, H2, O2, N2, CO2, and CH4) through the prepared polymer disclosed a synergetic effect, which was achieved by the presence of both bulky perfluorinated side groups and rigid saturated main chains. Addition poly(3-pentafluorophenyl-exo-tricyclononene-7) was more permeable than its metathesis analogue by a factor of 7–21, or the similar polymer with flexible main chains, poly(pentafluorostyrene), in relation to the gases tested. Therefore, this investigation opens the door to fluorinated addition polynorbornenes as new potential polymeric materials for membrane gas separation.

ACS Style

Gleb O. Karpov; Ilya L. Borisov; Alexey V. Volkov; Eugene Sh. Finkelshtein; Maxim V. Bermeshev. Synthesis and Gas Transport Properties of Addition Polynorbornene with Perfluorophenyl Side Groups. Polymers 2020, 12, 1 .

AMA Style

Gleb O. Karpov, Ilya L. Borisov, Alexey V. Volkov, Eugene Sh. Finkelshtein, Maxim V. Bermeshev. Synthesis and Gas Transport Properties of Addition Polynorbornene with Perfluorophenyl Side Groups. Polymers. 2020; 12 (6):1.

Chicago/Turabian Style

Gleb O. Karpov; Ilya L. Borisov; Alexey V. Volkov; Eugene Sh. Finkelshtein; Maxim V. Bermeshev. 2020. "Synthesis and Gas Transport Properties of Addition Polynorbornene with Perfluorophenyl Side Groups." Polymers 12, no. 6: 1.

Journal article
Published: 26 May 2020 in Polymers
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For the first time, the effect of the side-chain in polyalkylmethylsiloxane towards pervaporative removal of methyl tert-butyl ether (MTBE) from water was studied. The noticeable enhancement of separation factor during the pervaporation of 1 wt.% MTBE solution in water through the dense film (40–50 µm) can be achieved by substitution of a methyl group (separation factor 111) for heptyl (161), octyl (169) or decyl (180) one in polyalkylmethylsiloxane. Composite membrane with the selective layer (~8 µm) made of polydecylmethylsiloxane (M10) on top of microfiltration support (MFFK membrane) demonstrated MTBE/water separation factor of 310, which was 72% greater than for the dense film (180). A high separation factor together with an overall flux of 0.82 kg·m−2·h−1 allowed this M10/MFFK composite membrane to outperform the commercial composite membranes. The analysis of the concentration polarization modulus and the boundary layer thickness revealed that the feed flow velocity should be gradually increased from 5 cm·s−1 for an initial solution (1 wt.% of MTBE in water) to 13 cm·s−1 for a depleted solution (0.2 wt.% of MTBE in water) to overcome the concentration polarization phenomena in case of composite membrane M10/MFFK (Texp = 50 °C).

ACS Style

Ilya Borisov; Ivan Podtynnikov; Evgenia Grushevenko; Olga Scharova; Tatiana Anokhina; Sergey Makaev; Alexey Volkov; Vladimir Volkov. High Selective Composite Polyalkylmethylsiloxane Membranes for Pervaporative Removal of MTBE from Water: Effect of Polymer Side-chain. Polymers 2020, 12, 1213 .

AMA Style

Ilya Borisov, Ivan Podtynnikov, Evgenia Grushevenko, Olga Scharova, Tatiana Anokhina, Sergey Makaev, Alexey Volkov, Vladimir Volkov. High Selective Composite Polyalkylmethylsiloxane Membranes for Pervaporative Removal of MTBE from Water: Effect of Polymer Side-chain. Polymers. 2020; 12 (6):1213.

Chicago/Turabian Style

Ilya Borisov; Ivan Podtynnikov; Evgenia Grushevenko; Olga Scharova; Tatiana Anokhina; Sergey Makaev; Alexey Volkov; Vladimir Volkov. 2020. "High Selective Composite Polyalkylmethylsiloxane Membranes for Pervaporative Removal of MTBE from Water: Effect of Polymer Side-chain." Polymers 12, no. 6: 1213.

Journal article
Published: 04 February 2020 in Acta Crystallographica Section A Foundations and Advances
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The theoretical framework and a joint quasi-Newton–Levenberg–Marquardt–simulated annealing (qNLMSA) algorithm are established to treat an inverse X-ray diffraction tomography (XRDT) problem for recovering the 3D displacement field functionf Ctpd(r−r 0) =h · u(r−r 0) due to a Coulomb-type point defect (Ctpd) located at a pointr 0within a crystal [his the diffraction vector andu(r−r 0) is the displacement vector]. The joint qNLMSA algorithm operates in a special sequence to optimize the XRDT target function {\cal F}\{ {\cal P} \} in a χ2sense in order to recover the functionf Ctpd(r−r 0) [{\cal P} is the parameter vector that characterizes the 3D functionf Ctpd(r−r 0) in the algorithm search]. A theoretical framework based on the analytical solution of the Takagi–Taupin equations in the semi-kinematical approach is elaborated. In the case of true 2D imaging patterns (2D-IPs) with low counting statistics (noise-free), the joint qNLMSA algorithm enforces the target function {\cal F} \{ {\cal P} \} to tend towards the global minimum even if the vector {\cal P} in the search is initially chosen rather a long way from the true one.

ACS Style

Felix N. Chukhovskii; Petr V. Konarev; Vladimir V. Volkov. Towards a solution of the inverse X-ray diffraction tomography challenge: theory and iterative algorithm for recovering the 3D displacement field function of Coulomb-type point defects in a crystal. Acta Crystallographica Section A Foundations and Advances 2020, 76, 163 -171.

AMA Style

Felix N. Chukhovskii, Petr V. Konarev, Vladimir V. Volkov. Towards a solution of the inverse X-ray diffraction tomography challenge: theory and iterative algorithm for recovering the 3D displacement field function of Coulomb-type point defects in a crystal. Acta Crystallographica Section A Foundations and Advances. 2020; 76 (2):163-171.

Chicago/Turabian Style

Felix N. Chukhovskii; Petr V. Konarev; Vladimir V. Volkov. 2020. "Towards a solution of the inverse X-ray diffraction tomography challenge: theory and iterative algorithm for recovering the 3D displacement field function of Coulomb-type point defects in a crystal." Acta Crystallographica Section A Foundations and Advances 76, no. 2: 163-171.

Paper
Published: 24 January 2020 in RSC Advances
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Fibrin is a well-known tool in tissue engineering, but the structure of its modifications created to improve its properties remains undiscussed despite their importance, e.g. in designing biomaterials that ensure cell migration and lumenogenesis.

ACS Style

A. I. Shpichka; P. V. Konarev; Yu. M. Efremov; A. E. Kryukova; N. A. Aksenova; S. L. Kotova; A. A. Frolova; N. V. Kosheleva; O. M. Zhigalina; Vladimir Yusupov; D. N. Khmelenin; A. Koroleva; V. V. Volkov; V. E. Asadchikov; P. S. Timashev. Digging deeper: structural background of PEGylated fibrin gels in cell migration and lumenogenesis. RSC Advances 2020, 10, 4190 -4200.

AMA Style

A. I. Shpichka, P. V. Konarev, Yu. M. Efremov, A. E. Kryukova, N. A. Aksenova, S. L. Kotova, A. A. Frolova, N. V. Kosheleva, O. M. Zhigalina, Vladimir Yusupov, D. N. Khmelenin, A. Koroleva, V. V. Volkov, V. E. Asadchikov, P. S. Timashev. Digging deeper: structural background of PEGylated fibrin gels in cell migration and lumenogenesis. RSC Advances. 2020; 10 (8):4190-4200.

Chicago/Turabian Style

A. I. Shpichka; P. V. Konarev; Yu. M. Efremov; A. E. Kryukova; N. A. Aksenova; S. L. Kotova; A. A. Frolova; N. V. Kosheleva; O. M. Zhigalina; Vladimir Yusupov; D. N. Khmelenin; A. Koroleva; V. V. Volkov; V. E. Asadchikov; P. S. Timashev. 2020. "Digging deeper: structural background of PEGylated fibrin gels in cell migration and lumenogenesis." RSC Advances 10, no. 8: 4190-4200.

Journal article
Published: 03 January 2020 in Membranes
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A series of microfiltration membranes were fabricated by the extraction of polyisobutylene (PIB) from its immiscible blends with polymethylpentene (PMP). Three PIB with different molecular weight of 7.5 × 104 (Oppanol B15), 34 × 104 (Oppanol B50) and 110 × 104 (Oppanol B100) g/mol, respectively, were used to evaluate the effect of molecular weight on the porous structure and transport properties of resulting PMP-based membranes. To mimic the conditions of 3D printing, the flat-sheet membranes were fabricated by means of melting of mixtures of various PMP and PIB concentrations through the hot rolls at 240 ∘ C followed by a quick cooling. The rheology study of individual components and blends at 240 ∘ C revealed that PIB B50 possessed the most close flow curve to the pure PMP, and their blends demonstrated the lowest viscosity comparing to the compositions made of PIB with other molecular weights (B15 or B100). SEM images of the cross-section PMP membranes after PIB extraction (PMP/PIB = 55/45) showed that the use of PIB B50 allowed obtaining the sponge-like porous structure, whereas the slit-shaped pores were found in the case of PIB B15 and PIB B100. Additionally, PMP/B50 blends demonstrated the optimum combinations of mechanical properties (str = 9.1 MPa, E = 0.20 GPa), adhesion to steel (adh = 0.8 kPa) and retention performance (R240 nm = 99%, R38 nm = 39%). The resulting membranes were non- or low-permeable for water if the concentration of PIB B50 in the initial blends was 40 wt.% or lower. The optimal filtration performance was observed in the case of PMP/B50 blends with a ratio of 55/45 (Pwater = 1.9 kg/m2hbar, R240 nm = 99%, R38 nm = 39%) and 50/50 (Pwater = 1100 kg/m2hbar, R240 nm = 91%, R38 nm = 36%).

ACS Style

Sergey Ilyin; Viktoria Ignatenko; Tatyana Anokhina; Danila Bakhtin; Anna Kostyuk; Evgenia Dmitrieva; Sergey Antonov; Alexey Volkov. Formation of Microfiltration Membranes from PMP/PIB Blends: Effect of PIB Molecular Weight on Membrane Properties. Membranes 2020, 10, 9 .

AMA Style

Sergey Ilyin, Viktoria Ignatenko, Tatyana Anokhina, Danila Bakhtin, Anna Kostyuk, Evgenia Dmitrieva, Sergey Antonov, Alexey Volkov. Formation of Microfiltration Membranes from PMP/PIB Blends: Effect of PIB Molecular Weight on Membrane Properties. Membranes. 2020; 10 (1):9.

Chicago/Turabian Style

Sergey Ilyin; Viktoria Ignatenko; Tatyana Anokhina; Danila Bakhtin; Anna Kostyuk; Evgenia Dmitrieva; Sergey Antonov; Alexey Volkov. 2020. "Formation of Microfiltration Membranes from PMP/PIB Blends: Effect of PIB Molecular Weight on Membrane Properties." Membranes 10, no. 1: 9.

Journal article
Published: 14 December 2019 in Fibers
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It was shown for the first time that the conditions of thermal treatment of the casting solution significantly affect the morphology and transport properties of porous, flat, and hollow fiber polysulfone (PSf) membranes. It is ascertained that the main solution components that are subjected to thermo-oxidative destruction are the pore-forming agent polyethylene glycol (PEG) and solvent N-methyl-2-pyrrolidone (NMP). It is proved that hydroxyl groups of PEG actively react in the process of the casting solution thermo-oxidative destruction. It is shown that despite the chemical conversion taking place in the casting solution, their stability towards coagulation virtually does not change. The differences in the membrane morphology associated with the increase of thermal treatment time at 120 °C are not connected to the thermodynamic properties of the casting solutions, but with the kinetics of the phase separation. It is revealed that the change of morphology and transport properties of membranes is connected with the increase of the casting solution viscosity. The rise of solution viscosity resulted in the slowdown of the phase separation and formation of a more densely packed membrane structure with less pronounced macropores. It is determined experimentally that with the increase of casting solution thermal treatment time, the membrane selective layer thickness increases. This leads to the decrease of gas permeance and the rise of the He/CO2 selectivity for flat and hollow fiber membranes. In the case of hollow fibers, the fall of gas permeance is also connected with the appearance of the sponge-like layer at the outer surface of membranes. The increase of selectivity and decline of permeance indicates the reduction of selective layer pore size and its densification, which agrees well with the calculation results of the average membrane density. The results obtained are relevant to any polymeric casting solution containing NMP and/or PEG and treated at temperatures above 60 °C.

ACS Style

Ilya Borisov; Vladimir Vasilevsky; Dmitry Matveev; Anna Ovcharova; Alexey Volkov; Vladimir Volkov. Effect of Temperature Exposition of Casting Solution on Properties of Polysulfone Hollow Fiber Membranes. Fibers 2019, 7, 110 .

AMA Style

Ilya Borisov, Vladimir Vasilevsky, Dmitry Matveev, Anna Ovcharova, Alexey Volkov, Vladimir Volkov. Effect of Temperature Exposition of Casting Solution on Properties of Polysulfone Hollow Fiber Membranes. Fibers. 2019; 7 (12):110.

Chicago/Turabian Style

Ilya Borisov; Vladimir Vasilevsky; Dmitry Matveev; Anna Ovcharova; Alexey Volkov; Vladimir Volkov. 2019. "Effect of Temperature Exposition of Casting Solution on Properties of Polysulfone Hollow Fiber Membranes." Fibers 7, no. 12: 110.

Journal article
Published: 13 November 2019 in Membranes
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Heat stable salts (HSS) formed and continuously accumulated in the amine-based solvents due to solvent degradation and impurities in the feed gas can dramatically change the efficiency of the amine scrubbing process. HSS can be removed by using different methods including membrane separation such as electrodialysis (ED). In this work, we studied the effect of CO2 loading of the lean 30 wt % monoethanolamine (MEA) solution on the efficiency of HSS removal and MEA loss. In the model MEA solution containing HSS on the level of 48 meq/L, the carbon dioxide concentration was varied from 0.2 down to 0 mole (CO2)/mole (MEA). The reclaiming of model MEA solution was carried out by lab-scale two-stage ED unit when the concentrate stream after the first stage was additionally treated using ED (second stage) that allowed reducing MEA loss. It was shown that the decrease of carbon dioxide content from 0.2 down to 0 mole (CO2)/mole (MEA) resulted in a substantial reduction of both parameters—the MEA loss and the specific power consumption with respect to extracted HSS (from 140 down 37 kJ per 1 g of recovered HSS anions). This can be explained by the drop in the total concentration of ions formed by the interaction of MEA solution with carbon dioxide. However, the change of CO2 loading is associated with additional power consumption towards further solvent regeneration in the column. Based on the preliminary estimations of power consumption required for additional CO2 stripping with the respect to the power consumption of ED stage, it seems that lean solvent CO2 loading of 0.1 mole/mole provides an optimum for the power input at 25.9 MJ/kg(solvent).

ACS Style

Evgeniia Grushevenko; Stepan Bazhenov; Vladimir Vasilevsky; Eduard Novitsky; Maxim Shalygin; Alexey Volkov. Effect of Carbon Dioxide Loading on Removal of Heat Stable Salts from Amine Solvent by Electrodialysis. Membranes 2019, 9, 152 .

AMA Style

Evgeniia Grushevenko, Stepan Bazhenov, Vladimir Vasilevsky, Eduard Novitsky, Maxim Shalygin, Alexey Volkov. Effect of Carbon Dioxide Loading on Removal of Heat Stable Salts from Amine Solvent by Electrodialysis. Membranes. 2019; 9 (11):152.

Chicago/Turabian Style

Evgeniia Grushevenko; Stepan Bazhenov; Vladimir Vasilevsky; Eduard Novitsky; Maxim Shalygin; Alexey Volkov. 2019. "Effect of Carbon Dioxide Loading on Removal of Heat Stable Salts from Amine Solvent by Electrodialysis." Membranes 9, no. 11: 152.

Journal article
Published: 29 October 2019 in Polymers
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The present work evaluates the transport properties of thermoplastic R-BAPB polyimide based on 1,3-bis(3,3′,4,4′-dicarboxyphenoxy)benzene (dianhydride R) and 4,4′-bis(4-aminophenoxy)biphenyl (diamine BAPB). Both experimental studies and molecular dynamics simulations were applied to estimate the diffusion coefficients and solubilities of various gases, such as helium (He), oxygen (O2), nitrogen (N2), and methane (CH4). The validity of the results obtained was confirmed by studying the correlation of the experimental solubilities and diffusion coefficients of He, O2, and N2 in R-BAPB, with their critical temperatures and the effective sizes of the gas molecules, respectively. The solubilities obtained in the molecular dynamics simulations are in good quantitative agreement with the experimental data. A good qualitative relationship between the simulation results and the experimental data is also observed when comparing the diffusion coefficients of the gases. Analysis of the Robeson plots shows that R-BAPB has high selectivity for He, N2, and CO2 separation from CH4, which makes it a promising polymer for developing gas-separation membranes. From this point of view, the simulation models developed and validated in the present work may be put to effective use for further investigations into the transport properties of R-BAPB polyimide and nanocomposites based on it.

ACS Style

Igor V. Volgin; Maria V. Andreeva; Sergey V. Larin; Andrey L. Didenko; Gleb V. Vaganov; Ilya L. Borisov; Alexey V. Volkov; Leonid I. Klushin; Sergey V. Lyulin. Transport Properties of Thermoplastic R-BAPB Polyimide: Molecular Dynamics Simulations and Experiment. Polymers 2019, 11, 1775 .

AMA Style

Igor V. Volgin, Maria V. Andreeva, Sergey V. Larin, Andrey L. Didenko, Gleb V. Vaganov, Ilya L. Borisov, Alexey V. Volkov, Leonid I. Klushin, Sergey V. Lyulin. Transport Properties of Thermoplastic R-BAPB Polyimide: Molecular Dynamics Simulations and Experiment. Polymers. 2019; 11 (11):1775.

Chicago/Turabian Style

Igor V. Volgin; Maria V. Andreeva; Sergey V. Larin; Andrey L. Didenko; Gleb V. Vaganov; Ilya L. Borisov; Alexey V. Volkov; Leonid I. Klushin; Sergey V. Lyulin. 2019. "Transport Properties of Thermoplastic R-BAPB Polyimide: Molecular Dynamics Simulations and Experiment." Polymers 11, no. 11: 1775.