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Badal Tejedor, M., Nordgren, N., Schuleit, M., Millqvist-Fureby, A. & Rutland, M. W. (2019). AFM colloidal probe measurements implicate capillary condensation in punch-particle surface interactions during tableting. Paper presented at National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL. Abstracts of Papers of the American Chemical Society, 257
Open this publication in new window or tab >>AFM colloidal probe measurements implicate capillary condensation in punch-particle surface interactions during tableting
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2019 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:kth:diva-257614 (URN)000478860504727 ()
Conference
National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL
Note

QC 20190918

Available from: 2019-09-18 Created: 2019-09-18 Last updated: 2019-09-18Bibliographically approved
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
Skedung, L., Harris, K., Collier, E. S., Arvidsson, M., Wackerlin, A., Haag, W., . . . Rutland, M. W. (2018). Feeling Smooth: Psychotribological Probing of Molecular Composition. Tribology letters, 66(4), Article ID 138.
Open this publication in new window or tab >>Feeling Smooth: Psychotribological Probing of Molecular Composition
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2018 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 66, no 4, article id 138Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to evaluate whether smooth surfaces varying in surface chemistry could be perceptually distinguished with the sense of touch. A set of ten glass surfaces was prepared which varied systematically in terms of the molecular composition of a thin coating of low topography. The contact angle, contact angle hysteresis, and surface energy were evaluated as objective physical parameters characterizing each coating. Additionally, the interaction forces between a human finger and the different coatings were quantified and compared in terms of tactile friction coefficients. The surfaces were evaluated psychophysically in terms of perceived similarities and were then ranked according to pleasantness. The participants could perceptually distinguish between surfaces varying in surface chemistry and a primary and secondary perceptual dimension were identified as sufficient to distinguish them. The primary dimension correlates with surface free energy, but both tactile friction and surface energy contribute to this dimension depending on whether the coatings are organic or inorganic. The secondary dimension could not be identified explicitly in terms of a physical quantity but is discussed in terms of recent developments in the literature. Coated glass is characterized by high friction coefficient upon interaction with a human finger as well as significant hysteresis in the stroking directions (lower applied load and higher friction in the backward stroke). Despite the complexity of the tribology, pleasantness can be clearly linked to it, where low friction (high contact angle) materials receive a higher ranking.

Place, publisher, year, edition, pages
Plenum Publishing, 2018
Keywords
Tactile perception, Tactile discrimination, Surface chemistry, Psychotribology, Biotribology, Index finger, Tactile friction, Active touch
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:kth:diva-235993 (URN)10.1007/s11249-018-1077-z (DOI)000445957200001 ()
Note

QC 20181015

Available from: 2018-10-15 Created: 2018-10-15 Last updated: 2018-10-15Bibliographically approved
Shah, F. U., Holmgren, A., Rutland, M. W., Glavatskih, S. & Antzutkin, O. N. (2018). Interfacial Behavior of Orthoborate Ionic Liquids at Inorganic Oxide Surfaces Probed by NMR, IR, and Raman Spectroscopy. The Journal of Physical Chemistry C, 122(34), 19687-19698
Open this publication in new window or tab >>Interfacial Behavior of Orthoborate Ionic Liquids at Inorganic Oxide Surfaces Probed by NMR, IR, and Raman Spectroscopy
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2018 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 34, p. 19687-19698Article in journal (Refereed) Published
Abstract [en]

Absorption modes and the reactivity of nonhalogenated ionic liquids (ILs) at inorganic oxide surfaces of γ-Al2O3, MgO, and SiO2 particles were characterized using multinuclear (11B, 31P, and 29Si) solid-state magic-angle-spinning NMR, FTIR, and Raman spectroscopy. ILs are composed of the trihexyl(tetradecyl)phosphonium cation, [P6,6,6,14]+, and bis(mandelato)borate, [BMB]-, or bis(salicylato)borate, [BScB]-, anions. Spectroscopic measurements were performed on room-temperature (298 K) samples and samples exposed to 15 h at 373 K. The single-pulse 11B NMR data of heated [P6,6,6,14][BMB] mixed with the inorganic oxides showed a significant change in the spectra of the anion for all three oxides. In contrast, no such spectral changes were detected for heated [P6,6,6,14][BScB] mixed with the inorganic oxides. 31P MAS NMR data for the IL/metal oxide systems revealed interactions between [P6,6,6,14]+ and the surfaces of oxides. A significant intensity of 31P CP-MAS NMR signals indicated a low mobility of cations in these systems. The existence of strongly adhered surface layers of ILs on SiO2 particles was also confirmed by 1H-29Si CP-MAS NMR spectroscopy. FTIR and Raman spectroscopic data revealed strong interactions between the anions and the inorganic surfaces, and there is a strong correlation with the data obtained from NMR spectroscopy. Although their chemical structures are rather similar, the [BScB]- anion is more stable than the [BMB]- anion at the inorganic oxide surfaces.

Place, publisher, year, edition, pages
American Chemical Society, 2018
Keywords
Alumina, Aluminum oxide, Ionic liquids, Magic angle spinning, Magnesia, Negative ions, Nuclear magnetic resonance spectroscopy, Positive ions, Raman spectroscopy, Silica, Inorganic surfaces, Interfacial behaviors, Ionic liquid (ils), IR and Raman spectroscopy, Phosphonium cations, Solid state magic angle spinning NMR, Spectroscopic measurements, Strong interaction, Fourier transform infrared spectroscopy
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-236740 (URN)10.1021/acs.jpcc.8b06049 (DOI)000443923500041 ()2-s2.0-85052316588 (Scopus ID)
Note

Export Date: 22 October 2018; Article; Correspondence Address: Shah, F.U.; Chemistry of Interfaces, Luleå University of TechnologySweden; email: faisha@ltu.se; Funding details: LTU, Luther Theological University; Funding details: 621-2013-5171, VR, Vetenskapsrådet; Funding details: 621-2014-4694, VR, Vetenskapsrådet; Funding details: KAW2012.0078, Knut och Alice Wallenbergs Stiftelse; Funding text: The Knut and Alice Wallenberg Foundation (project number KAW2012.0078), Swedish Research Council (projects numbers 621-2013-5171 (O.N.A. and F.U.S.) and 621-2014-4694 (S.G.)), and the Norrbotten Research Council (NoFo) are gratefully acknowledged for supporting this work. We also thank the Foundation in memory of J. C. and Seth M. Kempe and the laboratory fond at LTU for providing grants, from which FTIR and Raman spectrometers have been purchased and a Varian/Chemagnetics CMX-360 NMR spectrometer at LTU has been upgraded. QC 20181022

Available from: 2018-10-22 Created: 2018-10-22 Last updated: 2018-10-22Bibliographically approved
Badal Tejedor, M., Pazesh, S., Nordgren, N., Schuleit, M., Rutland, M. W., Alderborn, G. & Millqvist-Fureby, A. (2018). Milling induced amorphisation andrecrystallization of α-lactose monohydrate. International Journal of Pharmaceutics, 537(1-2), 140-147
Open this publication in new window or tab >>Milling induced amorphisation andrecrystallization of α-lactose monohydrate
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2018 (English)In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 537, no 1-2, p. 140-147Article in journal (Refereed) Published
Abstract [en]

Preprocessing of pharmaceutical powders is a common procedure to condition the materials for a better manufacturing performance. However, such operations may induce undesired material properties modifications when conditioning particle size through milling, for example. Modification of both surface and bulk material structure will change the material properties, thus affecting the processability of the powder. Hence it is essential to control the material transformations that occur during milling. Topographical and mechanical changes in surface properties can be a preliminary indication of further material transformations. Therefore a surface evaluation of the alpha-lactose monohydrate after short and prolonged milling times has been performed. Unprocessed alpha-lactose monohydrate and spray dried lactose were evaluated in parallel to the milled samples as reference examples of the crystalline and amorphous lactose structure. Morphological differences between un-processed a-lactose, 1 h and 20 h milled lactose and spray dried lactose were detected from SEM and AFM images. Additionally, AFM was used to simultaneously characterize particle surface amorphicity by measuring energy dissipation. Extensive surface amorphicity was detected after 1 h of milling while prolonged milling times showed only a moderate particle surface amorphisation. Bulk material characterization performed with DSC indicated a partial amorphicity for the 1 h milled lactose and a fully amorphous thermal profile for the 20 h milled lactose. The temperature profiles however, were shifted somewhat in the comparison to the amorphous reference, particularly after extended milling, suggesting a different amorphous state compared to the spraydried material. Water loss during milling was measured with TGA, showing lower water content for the lactose amorphized through milling compared to spray dried amorphous lactose. The combined results suggest a surface-bulk propagation of the amorphicity during milling in combination with a different amorphous structural conformation to that of the amorphous spray dried lactose. The hardened surface may be due to either surface crystallization of lactose or to formation of a low-water glass transition.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
tableting, milling, lactose, amorphisation, recrystallization, mechanical properties, atomic force microscopy, differential scanning calorimetry, TGA
National Category
Pharmacology and Toxicology
Identifiers
urn:nbn:se:kth:diva-220332 (URN)10.1016/j.ijpharm.2017.12.021 (DOI)000424263700016 ()29262302 (PubMedID)2-s2.0-85038844261 (Scopus ID)
Note

QC 20171219

Available from: 2017-12-18 Created: 2017-12-18 Last updated: 2018-02-22Bibliographically approved
Nyström, L., Nordström, R., Strömstedt, A., Saunders, B., Alvarez-Asencio, R., Rutland, M. W. & Malmsten, M. (2018). Peptide-loaded microgels as antimicrobial surface coatings. Paper presented at 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA. Abstract of Papers of the American Chemical Society, 255
Open this publication in new window or tab >>Peptide-loaded microgels as antimicrobial surface coatings
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2018 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:kth:diva-232282 (URN)000435539907572 ()
Conference
255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA
Note

QC 20180719

Available from: 2018-07-19 Created: 2018-07-19 Last updated: 2018-07-19Bibliographically approved
Nyström, L., Nordström, R., Bramhill, J., Saunders, B., Alvarez-Asencio, R., Rutland, M. W. & Malmsten, M. (2018). Peptide-loaded microgels as carriers of antimicrobial peptides. Paper presented at 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA. Abstract of Papers of the American Chemical Society, 255
Open this publication in new window or tab >>Peptide-loaded microgels as carriers of antimicrobial peptides
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2018 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:kth:diva-232283 (URN)000435539907125 ()
Conference
255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA
Note

QC 20180719

Available from: 2018-07-19 Created: 2018-07-19 Last updated: 2018-07-19Bibliographically approved
Besharat, Z., Ghadami Yazdi, M., Wakeham, D., Johnson, M., Rutland, M. W., Göthelid, M. & Grönbeck, H. (2018). Se-C Cleavage of Hexane Selenol at Steps on Au(111). Langmuir, 34(8), 2630-2636
Open this publication in new window or tab >>Se-C Cleavage of Hexane Selenol at Steps on Au(111)
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2018 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 8, p. 2630-2636Article in journal (Refereed) Published
Abstract [en]

Selenols are considered as an alternative to thiols in self-assembled monolayers, but the Se-C bond is one limiting factor for their usefulness. In this study, we address the stability of the Se-C bond by a combined experimental and theoretical investigation of gas phase-deposited hexane selenol (CH3(CH2)(5)SeH) on Au(111) using photoelectron spectroscopy, scanning tunneling microscopy, and density functional theory (DFT). Experimentally, we find that initial adsorption leaves atomic Se on the surface without any carbon left on the surface, whereas further adsorption generates a saturated selenolate layer. The Se 3d component from atomic Se appears at 0.85 eV lower binding energy than the selenolate-related component. DFT calculations show that the most stable structure of selenols on Au(111) is in the form of RSe-Au-SeR complexes adsorbed on the unreconstructed Au(111) surface. This is similar to thiols on Au(111). Calculated Se 3d core-level shifts between elemental Se and selenolate in this structure nicely reproduce the experimentally recorded shifts. Dissociation of RSeH and subsequent formation of RH are found to proceed with high barriers on defect-free Au(111) terraces, with the highest barrier for scissoring R-Se. However, at steps, these barriers are considerably lower, allowing for Se-C bond breaking and hexane desorption, leaving elemental Se at the surface. Hexane is the selenol to selenolate formed by replacing the Se-C bond with a H-C bond by using the hydrogen liberated from transformation.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
Ray Photoelectron-Spectroscopy, Resolution Photoemission-Spectroscopy, Core-Level Shifts, Assembled Monolayers, Gold Surfaces, Mono Layers, Adsorption, Thiol, Alkanethiols, Stability
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-225082 (URN)10.1021/acs.langmuir.7b03713 (DOI)000426614100006 ()29405715 (PubMedID)2-s2.0-85042636157 (Scopus ID)
Funder
Swedish Research CouncilSwedish Foundation for Strategic Research
Note

QC 20180328

Available from: 2018-03-28 Created: 2018-03-28 Last updated: 2018-03-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8935-8070

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