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Filippov, Andrei, PhDORCID iD iconorcid.org/0000-0002-6810-1882
Publications (10 of 68) Show all publications
Filippov, A., Bhattacharyya, S. & Shah, F. U. (2019). CO2 absorption and ion mobility in aqueous choline-based ionic liquids. Journal of Molecular Liquids, 276, 748-752
Open this publication in new window or tab >>CO2 absorption and ion mobility in aqueous choline-based ionic liquids
2019 (English)In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 276, p. 748-752Article in journal (Refereed) Published
Abstract [en]

CO2 absorption and ion mobility are investigated in a series of 50/50 wt% aqueous solutions of choline-based ionic liquids with different cations and anions: [N1,1,4,2OH][Threo], [N1,1,5,2OH][Threo], [N1,1,6,2OH][Threo], [N1,1,5,2OH][β-ala] and [N1,1,5,2OH][Tau]. The process of CO2 absorption was completed in an hour reaching maximum of absorption capacity 0.07–0.10 wt% to ionic liquid (by 0.4–0.6 molar ratios). A rapid CO2 absorption is observed by the formation of solid product as a result of reaction between CO2 molecule and the ionic liquid. Diffusion coefficients of the cation and anion in the mixture are comparable while the diffusivity of water molecules is found to be quite different from the ions. In the process of CO2 absorption, an increase in the diffusivity of ions is observed due to the precipitation of solid products and depletion of ions contents in the liquid phase of the system. 13C NMR measurements of diffusivity of CO2 enriched with 13C isotope showed that a part of the absorbed CO2 remained in the liquid phase being physically and chemically bound to ions. The ionic liquid is re-cycled by evaporating water and releasing CO2 molecules using vacuum and temperature.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Ionic liquids, CO2 absorption, Nuclear magnetic resonance, Diffusivity of ions, Phase transformations
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-72056 (URN)10.1016/j.molliq.2018.12.045 (DOI)000459528600083 ()2-s2.0-85058405735 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-01-03 (svasva)

Available from: 2018-12-16 Created: 2018-12-16 Last updated: 2019-04-12Bibliographically approved
Kotenkov, S. A., Gnezdilov, O. I., Khaliullina, A. V., Antzutkin, O., Gimatdinov, R. S. & Filippov, A. (2019). Effect of Cholesterol and Curcumin on Ordering of DMPC Bilayers. Applied Magnetic Resonance, 50(1-3), 511-520
Open this publication in new window or tab >>Effect of Cholesterol and Curcumin on Ordering of DMPC Bilayers
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2019 (English)In: Applied Magnetic Resonance, ISSN 0937-9347, E-ISSN 1613-7507, Vol. 50, no 1-3, p. 511-520Article in journal (Refereed) Published
Abstract [en]

In this work, we compared the effects of curcumin and cholesterol directly competing to insert into the DMPC lipid bilayer during bilayer formation from an initially non-ordered state. 2H and 14N nuclear magnetic resonance spectroscopy showed that curcumin is not embedded deep in the lipid bilayer and interacts mainly with the head group of the lipid. In a more complex system of DMPC/CHOL/CUR, curcumin amplifies the effect of cholesterol on the ordering of lipid acyl chains.

Place, publisher, year, edition, pages
Springer, 2019
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-72752 (URN)10.1007/s00723-018-1102-2 (DOI)000458124800036 ()2-s2.0-85057198967 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-08 (johcin)

Available from: 2019-01-31 Created: 2019-01-31 Last updated: 2019-03-08Bibliographically approved
Arkhipov, V. P., Arkhipov, R. V., Kuzina, N. A. & Filippov, A. (2019). Oxyethylated Isononylphenols in Carbon Tetrachloride. Applied Magnetic Resonance
Open this publication in new window or tab >>Oxyethylated Isononylphenols in Carbon Tetrachloride
2019 (English)In: Applied Magnetic Resonance, ISSN 0937-9347, E-ISSN 1613-7507Article in journal (Refereed) Epub ahead of print
Abstract [en]

Translational diffusion coefficients of ethoxylated isononylphenol molecules C9H19C6H4O(C2H4O)nH in carbon tetrachloride were measured by nuclear magnetic resonance diffusometry. The hydrodynamic radii of the molecules were determined within the framework of the Stokes–Einstein relation. We showed that ethoxylated isononylphenols in carbon tetrachloride do not form micelles, and the dependence of the diffusion coefficients and, accordingly, the hydrodynamic radii of the nonionic surfactants on the number of oxyethylene groups have a kink in the region n = 6–8.

National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-76431 (URN)10.1007/s00723-019-01164-2 (DOI)000488902300002 ()
Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18
Butakov, A., Filippov, A., Gimatdinov, R. & Chernov, V. (2019). Peculiarities of NMR relaxation in micellar gels of Pluronic F-127. Journal of Dispersion Science and Technology, 40(3), 403-407
Open this publication in new window or tab >>Peculiarities of NMR relaxation in micellar gels of Pluronic F-127
2019 (English)In: Journal of Dispersion Science and Technology, ISSN 0193-2691, E-ISSN 1532-2351, Vol. 40, no 3, p. 403-407Article in journal (Refereed) Published
Abstract [en]

Based on the 1H relaxation of transverse nuclear magnetization of triblock-copolymer Pluronic F-127 in D2O, we proposed a model of the associated pluronic structure in which the polyethylene oxide of molecules in neighboring micelles are intertwined in regions of overlapping micellar coronas, while the polypropylene oxide cores of the micelles play a role of nodes in the 3D network. 

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Blockcopolymer, NMR relaxation, phase diagram, Poloxamer
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-71025 (URN)10.1080/01932691.2018.1470532 (DOI)000463092400010 ()
Note

Validerad;2019;Nivå 2;2019-04-03 (johcin)

Available from: 2018-09-28 Created: 2018-09-28 Last updated: 2019-04-12Bibliographically approved
Filippov, A., Antzutkin, O. & Shah, F. U. (2019). Rapid carbene formation increasing ion diffusivity in an imidazolium acetate ionic liquid confined between polar glass plates. Physical Chemistry, Chemical Physics - PCCP, 21(40), 22531-22538
Open this publication in new window or tab >>Rapid carbene formation increasing ion diffusivity in an imidazolium acetate ionic liquid confined between polar glass plates
2019 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 40, p. 22531-22538Article in journal (Refereed) Published
Abstract [en]

1-Ethyl-3-methyl-imidazolium acetate ([EMIM][OAc]) is one of the most widely used ionic liquids for various applications. This study is focussed on the chemical stability of [EMIM][OAc] on the surfaces of polar glass plates. 1H and 13C NMR spectroscopy and NMR diffusometry of [EMIM][OAc] IL confined between glass plates with a specific surface area 105–106 m−1 are thoroughly investigated. A rapid and spontaneous reaction took place on the surfaces of glass plates leading to the formation of neutral chemical moieties as evident by the appearance of new signals in the 1H NMR spectra. These new products are assigned as N-heterocyclic carbene (NHC) and acetic acid. These neutral chemical moieties have significantly increased the ion diffusivity by dissociation of the cation and the anion in [EMIM][OAc] IL. The yield and rate of formation of NHC and acetic acid are found to increase with the increasing surface area of polar glass plates and the time of contact between the IL and glass surfaces. Based on NMR spectroscopy, a dissociative reaction mechanism is proposed for the formation of free NHC in the neat [EMIM][OAc] IL.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Natural Sciences Chemical Sciences Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-76117 (URN)10.1039/C9CP04504J (DOI)31588443 (PubMedID)2-s2.0-85073483050 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-10-25 (johcin)

Available from: 2019-09-25 Created: 2019-09-25 Last updated: 2019-11-04Bibliographically approved
Filippov, A., Antzutkin, O. & Shah, F. U. (2019). Reactivity of CO2 with aqueous choline-based ionic liquids probed by solid-state NMR spectroscopy. Journal of Molecular Liquids, 286, Article ID 110918.
Open this publication in new window or tab >>Reactivity of CO2 with aqueous choline-based ionic liquids probed by solid-state NMR spectroscopy
2019 (English)In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 286, article id 110918Article in journal (Refereed) Published
Abstract [en]

CO2 absorption in a series of choline-based ionic liquids is investigated using solid-state 13C and 15N MAS NMR spectroscopy. Natural abundance and 13C enriched CO2 gas was purged through 50 wt% aqueous solutions of alkyldimethyl(2-hydroxyethyl)ammonium threonine, [N1,1,n,2OH][Threo], (alkyl = butyl, pentyl and hexyl) and pentyldimethyl(2-hydroxyethyl)ammonium taurine [N1,1,5,2OH][Tau]. The process of CO2 absorption results in precipitation of a solid sediment, which stays in equilibrium with the liquid phase. Upon degassing of the sample, the sediment is dissolved back into the IL-aqueous phase. Solid state 13C and 15N MAS NMR data suggest that the solid sediment is composed of neutral threonine (or taurine) in the zwitterionic forms and the liquid phase contained the products of reactions between the ionic liquids and CO2 molecules. A plausible mechanism for formation of the solid sediments and the reaction products in liquid phases is suggested.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
CO2 absorption, Aqueous choline-based ionic liquids, Liquid-solid equilibrium, 13C and 15N MAS, CP-MAS NMR
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-73873 (URN)10.1016/j.molliq.2019.110918 (DOI)000474308400033 ()2-s2.0-85065237523 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-05-14 (johcin)

Available from: 2019-05-07 Created: 2019-05-07 Last updated: 2019-08-16Bibliographically approved
Filippov, A., Gnezdilov, O. I., Luchkin, A. G. & Antzutkin, O. (2019). Self-diffusion of ethylammonium nitrate ionic liquid confined between modified polar glasses. Journal of Molecular Liquids, 284, 366-371
Open this publication in new window or tab >>Self-diffusion of ethylammonium nitrate ionic liquid confined between modified polar glasses
2019 (English)In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 284, p. 366-371Article in journal (Refereed) Published
Abstract [en]

Ethylammonium nitrate (EAN) ionic liquid confined between flat polar glass platesdemonstrates variable diffusivity that is sensitive to an external static magnetic field. Outside the magnetic field, diffusivity between the plates is higher than that in the bulk. However, after placing the system in a strong static magnetic field, the diffusivity gradually decreased. These processes occur during transformations between phases formed in EAN subjected to micrometer-size restrictions outside and within the magnetic field (Filippov et al., JMolLiq. [2018] 268, 49). In this study, we used samples of two types: (i) with roughened surface formed by treatment of the glass plates with aqueous solutions of hydrofluoric acid and (ii) with vacuum deposited TiO2 layers with a thickness of ca. 1 μm at glass-plate edges. Neither the surface modification of the glass plates, nor the TiO2 layers controlled thickness of EAN confined between glass-plates significantly changed the above-described effects, which have been observed in studies using untreated glass plates. Therefore, the range of systems with detected phase transformations in EAN and accompanying effects, such as accelerated diffusivity and change in diffusivity under the influence of a static magnetic field, was expanded to the systems with roughened surfaces and the systems with TiO2 layers controlled inter-plates distances. Results of experiments with roughened surfaces additionally suggested that the phase transformation of confined EAN in the external magnetic field is isotropic in nature rather than a phase transition from “layered to bulk” structures.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Nuclear magnetic resonance, DiffusivityIon dynamics, Phase transformations, Restricted diffusion
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-73599 (URN)10.1016/j.molliq.2019.04.021 (DOI)000469154300043 ()2-s2.0-85064072853 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-04-11 (johcin)

Available from: 2019-04-11 Created: 2019-04-11 Last updated: 2019-06-19Bibliographically approved
Dvoyashkin, D. & Filippov, A. (2018). Diffusivity of crude oils contained in macroporous medium: 1H NMR study. Mendeleev communications (Print), 2, 222-224
Open this publication in new window or tab >>Diffusivity of crude oils contained in macroporous medium: 1H NMR study
2018 (English)In: Mendeleev communications (Print), ISSN 0959-9436, E-ISSN 1364-551X, Vol. 2, p. 222-224Article in journal (Refereed) Published
Abstract [en]

Diffusivity of crude oils confined in pores of sand decreased with raising the fraction of oil at ordinary temperatures. This behaviour is suggested to be caused by adsorption of the high-molecular fractions of oils at the solid–liquid interface.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-68089 (URN)10.1016/j.mencom.2018.03.039 (DOI)000435626800039 ()2-s2.0-85044714633 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-03-27 (andbra)

Available from: 2018-03-27 Created: 2018-03-27 Last updated: 2018-07-26Bibliographically approved
Filippov, A., Azancheev, N., Gibaydullin, A., Bhattacharyya, S., Antzutkin, O. N. & Shah, F. U. (2018). Dynamic Properties of Imidazolium Orthoborate Ionic Liquids Mixed with Polyethylene Glycol Studied by NMR Diffusometry and Impedance Spectroscopy. Magnetic Resonance in Chemistry, 56(2), 113-119
Open this publication in new window or tab >>Dynamic Properties of Imidazolium Orthoborate Ionic Liquids Mixed with Polyethylene Glycol Studied by NMR Diffusometry and Impedance Spectroscopy
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2018 (English)In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 56, no 2, p. 113-119Article in journal (Refereed) Published
Abstract [en]

We used 1H pulsed field gradient (PFG) NMR to study the self-diffusion of polyethylene glycol (PEG) with average molecular mass of 200 and ions in mixtures of PEG with imidazolium bis(mandelato)borate (BMB) and imidazolium bis(oxalato)borate (BOB) ionic liquids (ILs). The ionic liquid was mixed with PEG in the concentration range of 0–100 wt%. Within the temperature range of 295 to 353 K, the diffusion coefficient of BMB is slower than that of the imidazolium cation. The diffusion coefficients of PEG, as well as the imidazolium cation and BMB anions, differ under all experimental conditions tested. This demonstrates that the IL in the mixture is present in at least a partially dissociated state. Generally, increasing the concentration of PEG leads to an increase in the diffusion coefficients of PEG and both the ions, and decreases their activation energy for diffusion. NMR chemical shift alteration analysis showed that the presence of PEG changes the chemical shifts of both ions but in different directions. Impedance spectroscopy was used to measure the ionic conductivity of the ionic liquids mixed with PEG.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
National Category
Chemical Sciences Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-64929 (URN)10.1002/mrc.4636 (DOI)000419519200009 ()28752526 (PubMedID)2-s2.0-85040248332 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-01-09 (svasva)

Available from: 2017-07-31 Created: 2017-07-31 Last updated: 2018-12-14Bibliographically approved
Filippov, A., Kurakin, S., Gnezdilov, O. & Antzutkin, O. (2018). Effect of magnetic field on diffusion of ethylammonium nitrate: water mixtures confined between polar glass plates. Journal of Molecular Liquids, 4, 45-51
Open this publication in new window or tab >>Effect of magnetic field on diffusion of ethylammonium nitrate: water mixtures confined between polar glass plates
2018 (English)In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 4, p. 45-51Article in journal (Refereed) Published
Abstract [en]

We used 1H NMR diffusometry to study mixtures of ethylammonium nitrate (EAN) with water (3.1–12.4 mol% of added H2O) confined between polar glass plates and exposed to a static magnetic field of 9.4 T. The presence of such restrictions reverses the concentration dependence of the diffusivities of the EA (ethylammonium) cation and water typical for the bulk system. The presence of water weakens the effects of a static magnetic field on diffusion of the EA cation as well as on proton exchange of –NH3 groups. Surprisingly, the amplitude of the echo signal of water protons decreases during exposure to the magnetic field and finally disappears, a phenomenon that depends on the concentration of water in the system. Based on experimental data, we suggest that water in the system is present in two states with different dynamic properties. One type of water formed in confinement possesses NMR relaxation time typical for liquids; its diffusivity can be measured by 1H NMR. The second type of water is formed upon exposure of the sample of the first type to the magnetic field and eventually includes all the water in the system. This type of water possesses “solid-like” NMR relaxation features that makes it “invisible” to the NMR diffusometry technique. We suggest that this second type of water is adsorbed onto the glass plates. Correspondingly, EAN exists in two liquid phases: the first one contains an EAN-water mixture, while the second one contains neat EAN, and forms on the microscopic scale range under the influence of a static magnetic field.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Nuclear magnetic resonance, Diffusivity, Ion dynamics, Water diffusion
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-71407 (URN)10.1016/j.molliq.2018.10.080 (DOI)000457660000005 ()2-s2.0-85055148175 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-11-01 (svasva)

Available from: 2018-11-01 Created: 2018-11-01 Last updated: 2019-03-08Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-6810-1882

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