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Glavatskih, Sergei
Publications (8 of 8) Show all publications
Rohlmann, P., Munavirov, B., Furo, I., Antzutkin, O., Rutland, M. W. & Glavatskih, S. (2019). Non-halogenated Ionic Liquid Dramatically Enhances Tribological Performance of Biodegradable Oils. Frontiers in Chemistry, 7, Article ID 98.
Open this publication in new window or tab >>Non-halogenated Ionic Liquid Dramatically Enhances Tribological Performance of Biodegradable Oils
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2019 (English)In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 7, article id 98Article in journal (Refereed) Published
Abstract [en]

It is demonstrated that a phosphonium orthoborate ionic liquid may serve as a wear reducing additive in biodegradable oils at steel-steel surfaces in the boundary lubrication regime. Tribological tests were performed in a bail-on-three plate configuration. A set of surface characterization techniques-SEM/EDS, FIB and white light interferometry were used to characterize surfaces following the tribotests and to observe the formation of any tribofilms. B-11 NMR was used to follow changes in the composition of the ionic-liquid-oil blends and to identify boron-containing decomposition products after the tribotests. The ionic liquid reduces the wear of steel surfaces by up to 92% compared to the neat oil at 90 degrees C; it is shown that the reduction in wear can be correlated with the formation of boron enriched patches in the boundary films.

Place, publisher, year, edition, pages
FRONTIERS MEDIA SA, 2019
Keywords
biodegradable oil, ionic liquid, wear, friction, boundary lubrication, NMR
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:kth:diva-246253 (URN)10.3389/fchem.2019.00098 (DOI)000459858200001 ()2-s2.0-85068538860 (Scopus ID)
Note

QC 20190401

Available from: 2019-04-01 Created: 2019-04-01 Last updated: 2019-10-04Bibliographically approved
Radiom, M., Pedraz, P., Pilkington, G., Rohlmann, P., Glavatskih, S. & Rutland, M. W. (2018). Anomalous Interfacial Structuring of a Non-Halogenated Ionic Liquid: Effect of Substrate and Temperature. Colloids and Interfaces, 2(4), Article ID 60.
Open this publication in new window or tab >>Anomalous Interfacial Structuring of a Non-Halogenated Ionic Liquid: Effect of Substrate and Temperature
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2018 (English)In: Colloids and Interfaces, ISSN 2504-5377, Vol. 2, no 4, article id 60Article in journal (Refereed) Published
Abstract [en]

We investigate the interfacial properties of the non-halogenated ionic liquid (IL), trihexyl(tetradecyl)phosphonium bis(mandelato)borate, [P6,6,6,14][BMB], in proximity to solid surfaces, by means of surface force measurement. The system consists of sharp atomic force microscopy (AFM) tips interacting with solid surfaces of mica, silica, and gold. We find that the force response has a monotonic form, from which a characteristic steric decay length can be extracted. The decay length is comparable with the size of the ions, suggesting that a layer is formed on the surface, but that it is diffuse. The long alkyl chains of the cation, the large size of the anion, as well as crowding of the cations at the surface of negatively charged mica, are all factors which are likely to oppose the interfacial stratification which has, hitherto, been considered a characteristic of ionic liquids. The variation in the decay length also reveals differences in the layer composition at different surfaces, which can be related to their surface charge. This, in turn, allows the conclusion that silica has a low surface charge in this aprotic ionic liquid. Furthermore, the effect of temperature has been investigated. Elevating the temperature to 40 °C causes negligible changes in the interaction. At 80 °C and 120 °C, we observe a layering artefact which precludes further analysis, and we present the underlying instrumental origin of this rather universal artefact.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
non-halogenated ionic liquids, interfacial layers, atomic force microscopy, surface forces, surface charge, surface interactions, thermal instability
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-248994 (URN)10.3390/colloids2040060 (DOI)
Note

QC 20190619

Available from: 2019-04-10 Created: 2019-04-10 Last updated: 2019-06-19Bibliographically approved
Pilkington, G. A., Harris, K., Bergendal, E., Reddy, A. B., Pålsson, G. K., Vorobiev, A., . . . Rutland, M. W. (2018). Electro-responsivity of ionic liquid boundary layers in a polar solvent revealed by neutron reflectance. Journal of Chemical Physics, 148(19), Article ID 193806.
Open this publication in new window or tab >>Electro-responsivity of ionic liquid boundary layers in a polar solvent revealed by neutron reflectance
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2018 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 148, no 19, article id 193806Article in journal (Refereed) Published
Abstract [en]

Using neutron reflectivity, the electro-responsive structuring of the non-halogenated ionic liquid (IL) trihexyl(tetradecyl)phosphonium-bis(mandelato)borate, [P6,6,6,14][BMB], has been studied at a gold electrode surface in a polar solvent. For a 20% w/w IL mixture, contrast matched to the gold surface, distinct Kiessig fringes were observed for all potentials studied, indicative of a boundary layer of different composition to that of the bulk IL-solvent mixture. With applied potential, the amplitudes of the fringes from the gold-boundary layer interface varied systematically. These changes are attributable to the differing ratios of cations and anions in the boundary layer, leading to a greater or diminished contrast with the gold electrode, depending on the individual ion scattering length densities. Such electro-responsive changes were also evident in the reflectivities measured for the pure IL and a less concentrated (5% w/w) IL-solvent mixture at the same applied potentials, but gave rise to less pronounced changes. These measurements, therefore, demonstrate the enhanced sensitivity achieved by contrast matching the bulk solution and that the structure of the IL boundary layers formed in mixtures is strongly influenced by the bulk concentration. Together these results represent an important step in characterising IL boundary layers in IL-solvent mixtures and provide clear evidence of electro-responsive structuring of IL ions in their solutions with applied potential.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2018
Keywords
Cross level, environmental management, interplay, spatial planning, strategic planning
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-222497 (URN)10.1063/1.5001551 (DOI)000432853800010 ()2-s2.0-85041289749 (Scopus ID)
Note

QC 20180212

Available from: 2018-02-12 Created: 2018-02-12 Last updated: 2018-06-27Bibliographically approved
Sarman, S., Wang, Y.-L., Rohlmann, P., Glavatskih, S. & Laaksonen, A. (2018). Rheology of phosphonium ionic liquids: a molecular dynamics and experimental study. Physical Chemistry, Chemical Physics - PCCP, 20(15), 10193-10203
Open this publication in new window or tab >>Rheology of phosphonium ionic liquids: a molecular dynamics and experimental study
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2018 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, no 15, p. 10193-10203Article in journal (Refereed) Published
Abstract [en]

We have studied the rheological behavior of the ionic liquid trihexyl(tetradecyl)phosphonium bis(mandelato)borate, [P-66614][BMB], and compared it with that of another ionic liquid, namely trihexyl(tetradecyl)phosphonium chloride, [P-66614][Cl]. The non-halogenated [P-66614][BMB] has been selected as it is known to provide enhanced lubrication performance and is, consequently, of technological importance. The ionic liquid [P-66614][Cl], despite its relatively simple anion, exhibits viscosities very similar to those of [P-66614][BMB], making it an excellent reference fluid for the modeling study. The viscosities of the ionic liquids have been obtained by equilibrium atomistic simulations using the Green-Kubo relation, and by performing nonequilibrium shear flow simulations. The influence of the simulation system size and a reduction of the atomic charges on the viscosities of the ionic liquids are systematically studied. The atomic charges are reduced to mimic the temperature dependent charge transfer and polarization effects. It has been found that scaling the point charges with factors between 0.60 and 0.80 from full ion charges can provide reliable viscosities of [P-66614][BMB], consistent with the experimentally measured viscosities within the studied temperature interval from 373 to 463 K. The viscosities of [P-66614][Cl] have been obtained with scaling factors between 0.80 and 1.0 reflecting the lower polarizability and charge transfer effects of the chloride anion.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2018
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-227771 (URN)10.1039/c7cp08349a (DOI)000430537600052 ()29594283 (PubMedID)2-s2.0-85045831933 (Scopus ID)
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Note

QC 20180514

Available from: 2018-05-14 Created: 2018-05-14 Last updated: 2018-05-14Bibliographically approved
Shu, J., Harris, K., Munavirov, B., Westbroek, R., Leckner, J. & Glavatskih, S. (2018). Tribology of polypropylene and Li-complex greases with ZDDP and MoDTC additives. Tribology International, 118, 189-195
Open this publication in new window or tab >>Tribology of polypropylene and Li-complex greases with ZDDP and MoDTC additives
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2018 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 118, p. 189-195Article in journal (Refereed) Published
Abstract [en]

The influence of thickener and additive interactions on grease lubricating performance is examined. Polypropylene and lithium complex thickened (Li-complex) greases were tested both as neat greases and with a 2 wt% addition of ZDDP and/or MoDTC. A combination of ZDDP and MoDTC in the polypropylene grease provided the lowest friction with greater longevity compared to the Li-complex grease with the same additives, independent of sliding speed, contact pressure, temperature or type of sliding: continuous vs. reciprocating. The additive combination of ZDDP and MoDTC provided the best antiwear performance in both greases. Depending on the grease sample type, EDS revealed the presence of iron, zinc, phosphorous, sulfur, and molybdenum within the tribofilms.

Place, publisher, year, edition, pages
Elsevier Ltd, 2018
Keywords
Friction, Li-complex grease, MoDTC, Polymer grease, Wear, ZDDP
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-216798 (URN)10.1016/j.triboint.2017.09.028 (DOI)000423004700019 ()2-s2.0-85030721895 (Scopus ID)
Note

QC 20171114

Available from: 2017-11-14 Created: 2017-11-14 Last updated: 2018-02-02Bibliographically approved
Filippov, A., Gnezdilov, O. I., Hjalmarsson, N., Antzutkin, O. N., Glavatskih, S., Furo, I. & Rutland, M. W. (2017). Acceleration of diffusion in ethylammonium nitrate ionic liquid confined between parallel glass plates. Physical Chemistry, Chemical Physics - PCCP, 19(38), 25853-25858
Open this publication in new window or tab >>Acceleration of diffusion in ethylammonium nitrate ionic liquid confined between parallel glass plates
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2017 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 38, p. 25853-25858Article in journal (Refereed) Published
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-216606 (URN)10.1039/c7cp01772c (DOI)000412275200006 ()28932828 (PubMedID)2-s2.0-85030660874 (Scopus ID)
Note

QC 20171110

Available from: 2017-11-10 Created: 2017-11-10 Last updated: 2017-11-10Bibliographically approved
Javed, M. A., Ahola, S., Hakansson, P., Mankinen, O., Aslam, M. K., Filippov, A., . . . Telkki, V.-V. (2017). Y Structure and dynamics elucidation of ionic liquids using multidimensional Laplace NMR. Chemical Communications, 53(80), 11056-11059
Open this publication in new window or tab >>Y Structure and dynamics elucidation of ionic liquids using multidimensional Laplace NMR
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2017 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 80, p. 11056-11059Article in journal (Refereed) Published
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-216605 (URN)10.1039/c7cc05493a (DOI)000412410700018 ()28948273 (PubMedID)2-s2.0-85030787744 (Scopus ID)
Note

QC 20171115

Available from: 2017-11-15 Created: 2017-11-15 Last updated: 2017-11-15Bibliographically approved
Rutland, M. W., Glavatskih, S. & Notley, S. (2015). Traction Drive Fluid. .
Open this publication in new window or tab >>Traction Drive Fluid
2015 (English)Patent (Other (popular science, discussion, etc.))
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-249121 (URN)
Note

QRC 20190823

Available from: 2019-04-10 Created: 2019-04-10 Last updated: 2019-08-23Bibliographically approved
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