umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Andersson, Ove
Publications (10 of 86) Show all publications
Carvalho, P. H. B., Mace, A., Bull, C. L., Funnell, N. P., Tulk, C. A., Andersson, O. & Häussermann, U. (2019). Elucidation of the pressure induced amorphization of tetrahydrofuran clathrate hydrate. Journal of Chemical Physics, 150(20), Article ID 204506.
Open this publication in new window or tab >>Elucidation of the pressure induced amorphization of tetrahydrofuran clathrate hydrate
Show others...
2019 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 150, no 20, article id 204506Article in journal (Refereed) Published
Abstract [en]

The type II clathrate hydrate (CH) THF·17 H2O (THF = tetrahydrofuran) is known to amorphize on pressurization to ∼1.3 GPa in the temperature range 77–140 K. This seems to be related to the pressure induced amorphization (PIA) of hexagonal ice to high density amorphous (HDA) ice. Here, we probe the PIA of THF-d8 · 17 D2O (TDF-CD) at 130 K by in situthermal conductivity and neutron diffraction experiments. Both methods reveal amorphization of TDF-CD between 1.1 and 1.2 GPa and densification of the amorphous state on subsequent heating from 130 to 170 K. The densification is similar to the transition of HDA to very-high-density-amorphous ice. The first diffraction peak (FDP) of the neutron structure factor function, S(Q), of amorphous TDF-CD at 130 K appeared split. This feature is considered a general phenomenon of the crystalline to amorphous transition of CHs and reflects different length scales for D-D and D-O correlations in the water network and the cavity structure around the guest. The maximum corresponding to water-water correlations relates to the position of the FDP of HDA ice at ∼1 GPa. Upon annealing, the different length scales for water-water and water-guest correlations equalize and the FDP in the S(Q) of the annealed amorph represents a single peak. The similarity of local water structures in amorphous CHs and amorphous ices at in situ conditions is confirmed from molecular dynamics simulations. In addition, these simulations show that THF guest molecules are immobilized and retain long-range correlations as in the crystal.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-161741 (URN)10.1063/1.5083958 (DOI)000473301400044 ()31153163 (PubMedID)
Funder
Swedish Foundation for Strategic Research
Available from: 2019-07-25 Created: 2019-07-25 Last updated: 2019-07-25Bibliographically approved
Andersson, O., Carvalho, P. H. B., Hsu, Y.-J. & Haussermann, U. (2019). Transitions in pressure-amorphized clathrate hydrates akin to those of amorphous ices. Journal of Chemical Physics, 151(1), Article ID 014502.
Open this publication in new window or tab >>Transitions in pressure-amorphized clathrate hydrates akin to those of amorphous ices
2019 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 151, no 1, article id 014502Article in journal (Refereed) Published
Abstract [en]

Type II clathrate hydrates (CHs) were studied by thermal and dielectric measurements. All CHs amorphize, or collapse, on pressurization to 1.3 GPa below 135 K. After heating to 160 K at 1 GPa, the stability of the amorphous states increases in a process similar to the gradual high density to very high density amorphous ice (HDA to VHDA) transition. On a subsequent pressure decrease, the amorphized CHs expand partly irreversibly similar to the gradual VHDA to expanded HDA ice transformation. After further heating at 1 GPa, weak transition features appear near the HDA to low density amorphous ice transition. The results suggest that CH nucleation sites vanish on heating to 160 K at 1 GPa and that a sluggish partial phase-separation process commences on further heating. The collapsed CHs show two glass transitions (GTs), GT1 and GT2. GT1 is weakly pressure-dependent, 12 K GPa(-1), with a relaxation time of 0.3 s at 140 K and 1 GPa; it is associated with a weak heat capacity increase of 3.7 J H2O-mol(-1) K-1 in a 18 K range and an activation energy of only 38 kJ mol(-1) at 1 GPa. The corresponding temperature of GT2 is 159 K at 0.4 GPa with a pressure dependence of 36 K GPa(-1); it shows 5.5 times larger heat capacity increase and 4 times higher activation energy than GT1. GT1 is observed also in HDA and VHDA, whereas GT2 occurs just above the crystallization temperature of expanded HDA and only within its similar to 0.2-0.7 GPa stable pressure range.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-161824 (URN)10.1063/1.5096981 (DOI)000474214600007 ()31272168 (PubMedID)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-12Bibliographically approved
Andersson, O. & Häussermann, U. (2018). A Second Glass Transition in Pressure Collapsed Type II Clathrate Hydrates. Paper presented at International Conference on NMR Spectroscopy of Biomolecules, APR 16-17, 2016, Univ Michigan, Ann Arbor, MI. Journal of Physical Chemistry B, 122(15), 4376-4384
Open this publication in new window or tab >>A Second Glass Transition in Pressure Collapsed Type II Clathrate Hydrates
2018 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 122, no 15, p. 4376-4384Article in journal (Refereed) Published
Abstract [en]

Type II clathrate hydrates (CHs) M·17 H2O, with M = tetrahydrofuran (THF) or 1,3-dioxolane, are known to collapse, or amorphize, on pressurization to ∼1.3 GPa in the temperature range 77–140 K. On heating at 1 GPa, these pressure-amorphized CH states show a weak, stretched sigmoid-shaped, heat-capacity increase because of a glass transition. Here we use thermal conductivity and heat capacity measurements to show that also type II CH with M = cyclobutanone (CB) collapses on isothermal pressurization and undergoes a similar, weak, glass transition upon heating at 1 GPa. Furthermore, we reveal for both THF CH and CB CH a second, much more pronounced, glass transition at temperatures above the thermally weak glass transition on heating in the 0.2–0.7 GPa range. This result suggests the general occurrence of two glass transitions in water-rich (94 mol %) pressure-collapsed CHs. Because of a large increase in dielectric permittivity concurrently as the weak heat capacity increase, the first glass transition must be due to kinetic unfreezing of water molecules. The thermal features of the second glass transition, measured on isobaric temperature cycling, are typical of a glass–liquid–glass transition, which suggests that pressure-amorphized CHs transform reversibly to liquids.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-151173 (URN)10.1021/acs.jpcb.8b01269 (DOI)000430784000019 ()29584946 (PubMedID)2-s2.0-85045728560 (Scopus ID)
Conference
International Conference on NMR Spectroscopy of Biomolecules, APR 16-17, 2016, Univ Michigan, Ann Arbor, MI
Available from: 2018-09-05 Created: 2018-09-05 Last updated: 2018-09-05Bibliographically approved
Johari, G. P., Andersson, O. & Sundqvist, B. (2018). Instability and thermal conductivity of pressure-densified and elastically altered orientational glass of Buckminsterfullerene. Journal of Chemical Physics, 148(14), Article ID 144502.
Open this publication in new window or tab >>Instability and thermal conductivity of pressure-densified and elastically altered orientational glass of Buckminsterfullerene
2018 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 148, no 14, article id 144502Article in journal (Refereed) Published
Abstract [en]

We report on the temperature, pressure and time (T, p and t)- dependent features of thermal conductivity, k, of partially ordered, non-equilibrium state of C60-OG, the orientational glass of Buckminsterfullerene (at T below the orientational freezing temperature Tog) made more unstable (i) by partially depressurizing its high-p formed state to elastically expand it, and (ii) by further pressurizing that state to elastically contract it. The sub-Tog effects observed on heating of C60-OG differ from those of glasses, because phonon propagation depends on the ratio of two well-defined orientational states of C60 molecules and the density of the solid. A broad peak-like feature appears at T near Tog in the k-T plots of C60-OG formed at 0.7 and heated at 0.2 GPa, which we attribute to partial overlap of the sub-Tog and Tog features. A sub-Tog local minimum appears in the k -T plots at T well below Tog  of C60-OG formed at 0.1 GPa and heated at 0.5 GPa, and corresponds to the state of maximum disorder. Although Buckminsterfullerene is regarded as an orientationally-disordered crystal, variation of its properties with T and p is qualitatively different from other such crystals. We discuss the findings in terms of the nature of its disorder, sensitivity of its rotational dynamics to temperature and the absence of the Johari-Goldstein relaxation. All seem to affect the phenomenology of its glass-like transition.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2018
Keywords
C60, pressure densified glasses, high-pressure
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-147236 (URN)10.1063/1.5019832 (DOI)000430128600028 ()29655324 (PubMedID)
Available from: 2018-04-27 Created: 2018-04-27 Last updated: 2018-06-09Bibliographically approved
Bair, S. S., Andersson, O., Qureshi, F. S. & Schirru, M. M. (2018). New EHL Modeling Data for the Reference Liquids Squalane and Squalane Plus Polyisoprene. Tribology Transactions, 61(2), 247-255
Open this publication in new window or tab >>New EHL Modeling Data for the Reference Liquids Squalane and Squalane Plus Polyisoprene
2018 (English)In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 61, no 2, p. 247-255Article in journal (Refereed) Published
Abstract [en]

An important part of the new quantitative approach to elastohydrodynamic lubrication (EHL) is the use of reference liquids with well-characterized thermophysical properties. New measurements are reported for the thermal and rheological properties of squalane to high pressure and of high shear rate and high-frequency viscosity of squalane thickened with polyisoprene (SQL + PIP) at ambient pressure. The glass transition viscosity of squalane at ambient pressure was found from published viscosity measurements and new glass transition measurements by transient hot wire. The glass transition viscosity so determined was incorporated into the improved Yasutomi model and the calculated glass transition temperatures as a function of pressure are comparable to those directly measured, although the hybrid model yields better agreement. The glass transition viscosity of squalane by any definition must be substantially lower than the “universal value” of 1012 Pa·s. The second Newtonian inflection cannot be characterized in steady shear at ambient pressure for SQL + PIP due to cavitation; however, acoustic viscometry with matching layer does characterize the second Newtonian inflection. To form the analogy between steady and oscillatory shear requires that the steady shear rate be compared with the ordinary frequency rather than the angular frequency for SQL + PIP.

Place, publisher, year, edition, pages
Society of Tribologists and Lubrication Engineers, 2018
Keywords
Quantitative elastohydrodynamics, high-pressure rheology, high-shear viscosity, reference liquids
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-147235 (URN)10.1080/10402004.2017.1310339 (DOI)000432223000006 ()2-s2.0-85018187027 (Scopus ID)
Available from: 2018-04-27 Created: 2018-04-27 Last updated: 2018-06-13Bibliographically approved
Andersson, O. (2018). Thermal conductivity of normal and deuterated water, crystalline ice, and amorphous ices. Journal of Chemical Physics, 149(12), Article ID 124506.
Open this publication in new window or tab >>Thermal conductivity of normal and deuterated water, crystalline ice, and amorphous ices
2018 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 149, no 12, article id 124506Article in journal (Refereed) Published
Abstract [en]

The effect of deuteration on the thermal conductivity kappa of water, crystalline ice, and amorphous ices was studied using the pressure induced amorphization of hexagonal ice, ice Ih, to obtain the deuterated, D2O, forms of low-density amorphous (LDA), high-density amorphous (HDA), and very-high density amorphous (VHDA) ices. Upon deuteration, kappa of ice Ih decreases between 3% and 4% in the 100-270 K range at ambient pressure, but the effect diminishes on densification at 130 K and vanishes just prior to amorphization near 0.8 GPa. The unusual negative value of the isothermal density rho dependence of kappa for ice Ih, g = (d ln kappa/d ln rho)(T) = -4.4, is less so for deuterated ice: g = -3.8. In the case of the amorphous ices and liquid water, kappa of water decreases by 3.5% upon deuteration at ambient conditions, whereas K of HDA and VHDA ices instead increases by up to 5% for pressures up to 1.2 GPa at 130 K, despite HDA's and VHDA's structural similarities with water. The results are consistent with significant heat transport by librational modes in amorphous ices as well as water, and that deuteration increases phonon-phonon scattering in crystalline ice. Heat transport by librational modes is more pronounced in D2O than in H2O at low temperatures due to a deuteration-induced red-shift of librational mode frequencies. Moreover, the results show that kappa of deuterated LDA ice is 4% larger than that of normal LDA at 130 K, and both forms display an unusual temperature dependence of kappa, which is reminiscent of that for crystals (kappa similar to T (-1)), and a unique negative pressure dependence of kappa, which likely is linked to local-order structural similarities to ice Ih. 

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2018
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-152894 (URN)10.1063/1.5050172 (DOI)000446120700023 ()30278676 (PubMedID)
Funder
Magnus Bergvall FoundationCarl Tryggers foundation
Available from: 2018-10-31 Created: 2018-10-31 Last updated: 2018-10-31Bibliographically approved
Johari, G. P. & Andersson, O. (2017). Structural relaxation and thermal conductivity of high-pressure formed, high-density di-n-butyl phthalate glass and pressure induced departures from equilibrium state. Journal of Chemical Physics, 146(23), Article ID 234505.
Open this publication in new window or tab >>Structural relaxation and thermal conductivity of high-pressure formed, high-density di-n-butyl phthalate glass and pressure induced departures from equilibrium state
2017 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 146, no 23, article id 234505Article in journal (Refereed) Published
Abstract [en]

We report a study of structural relaxation of high-density glasses of di-n-butyl phthalate (DBP) by measuring thermal conductivity, κ, under conditions of pressure and temperature (p,T) designed to modify both the vibrational and configurational states of a glass. Various high-density glassy states of DBP were formed by (i) cooling the liquid under a fixed high p and partially depressurizing the glass, (ii) isothermal annealing of the depressurized glass, and (iii) pressurizing the glass formed by cooling the liquid under low p. At a given low p, κ of the glass formed by cooling under high p is higher than that of the glass formed by cooling under low p, and the difference increases as glass formation p is increased. κ of the glass formed under 1 GPa is ∼20% higher at ambient p than κ of the glass formed at ambient p. On heating at low p, κ decreases until the glass to liquid transition range is reached. This is the opposite of the increase in κ observed when a glass formed under a certain p is heated under the same p. At a given high p, κ of the low-density glass formed by cooling at low p is lower than that of the high-density glass formed by cooling at that high p. On heating at high p, κ increases until the glass to liquid transition range is reached. The effects observed are due to a thermally assisted approach toward equilibrium at p different from the glass formation p. In all cases, the density, enthalpy, and entropy would change until the glasses become metastable liquids at a fixed p, thus qualitatively relating κ to variation in these properties.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2017
National Category
Atom and Molecular Physics and Optics Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-137628 (URN)10.1063/1.4986063 (DOI)000404051000013 ()
Available from: 2017-07-19 Created: 2017-07-19 Last updated: 2018-06-09Bibliographically approved
Andersson, O. & Johari, G. P. (2016). Sub-Tg features of glasses formed by cooling glycerol under pressure – Additional incompatibility of vibrational with configurational states in the depressurized, high density glass. Journal of Chemical Physics, 145, Article ID 204506.
Open this publication in new window or tab >>Sub-Tg features of glasses formed by cooling glycerol under pressure – Additional incompatibility of vibrational with configurational states in the depressurized, high density glass
2016 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 145, article id 204506Article in journal (Refereed) Published
Abstract [en]

The vibrational state of a glass is naturally incompatible with its configurational state, which makes the glass structurally unstable. When a glass is kept at constant temperature, both the vibrational and configurational states of a glass change with time until it becomes metastable (equilibrium) liquid and the two states become compatible. The process, known as structural relaxation, occurs at a progressively higher rate during heating, and the properties of a glass change accordingly. We add to this incompatibility by depressurizing a glass that had been formed by cooling a liquid under a high pressure, p, and then investigate the effects of the added incompatibility by studying thermal conductivity, κ, and the heat capacity per unit volume ρCp of the depressurized glass.We use glycerol for the purpose and study first the changes in the features of κ and of ρCp during glass formation oncooling under a set of different p. We then partially depressurize the glass and study the effect of the p-induced instability on the features of and Cp as the glass is isobarically heated to the liquid state.At a given low p, the glass configuration that was formed by cooling at high-p had a higher κ than the glass configuration that was formed by cooling at a low p. The difference is more when the glass is formed at a higher p and/or is depressurized to a lower p. On heating at a low p, its κ decreases before its glass-liquid transition range is reached. The effect is the opposite of the increase in observed on heating a glass at the same p under which it was formed. It is caused by thermally assisted loss of the added incompatibility of configurational and vibrational states of a high-p formed glass kept at low p. If a glass formed under a low-p is pressurized and then heated under high p, it would show the opposite effect, i.e., its κ would first increase to its high p value before its glass-to-liquid transition range.

Keywords
glass, glycerol, sub-glass, pressure
National Category
Condensed Matter Physics
Research subject
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-128348 (URN)10.1063/1.4968019 (DOI)000390118200033 ()
Funder
Swedish Research Council, 621-2012-3336
Available from: 2016-12-02 Created: 2016-12-02 Last updated: 2018-06-09Bibliographically approved
Andersson, O. & Johari, G. P. (2016). Thermal conductivity of Glycerol’s liquid, glass, and crystal states, glass-liquid-glass transition, and crystallization at high pressures. Journal of Chemical Physics, 144, Article ID 064504.
Open this publication in new window or tab >>Thermal conductivity of Glycerol’s liquid, glass, and crystal states, glass-liquid-glass transition, and crystallization at high pressures
2016 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 144, article id 064504Article in journal (Refereed) Published
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2016
National Category
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-117362 (URN)10.1063/1.4941335 (DOI)000371607800022 ()
Funder
Magnus Bergvall FoundationSwedish Research Council, 621-2012-3336Carl Tryggers foundation
Available from: 2016-02-27 Created: 2016-02-27 Last updated: 2018-06-07Bibliographically approved
Krivchikov, A. I. & Andersson, O. (2016). Thermal Conductivity of Triphenyl Phosphite's Liquid, Glassy, and Glacial States. Journal of Physical Chemistry B, 120(10), 2845-2853
Open this publication in new window or tab >>Thermal Conductivity of Triphenyl Phosphite's Liquid, Glassy, and Glacial States
2016 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 120, no 10, p. 2845-2853Article in journal (Refereed) Published
Abstract [en]

The thermal conductivity kappa and heat capacity per unit volume rho C-p of triphenyl phosphite (TPP) were measured under different pressure and temperature conditions, and with time during the sluggish liquid to glacial state transformation at temperatures about 15 K above the glass transition temperature. As the transformation slowly proceeds during several hours, rho C-p decreases monotonically from that of the liquid state to a value close to that of the vitrified state. Concurrently, kappa increases nonmonotonically with an intermediate local maximum followed by a minimum, before the final rise to a higher kappa. The properties of the ultimately formed glacial state depend on the thermal history, which implies that the state formed under these conditions is a heterogeneous mixture of nanocrystals and mainly amorphous-like solid, and that the relative amount and microstructure depend on the conditions of the transformation. The nonmonotonic changes in phonon propagation during the liquid to glacial transformation suggest microstructural changes which are consistent with a liquid-liquid transformation and sluggish growth of nanocrystals within amorphous-like solid domains. The isobaric thermal conductivity of the as-formed glacial state shows a reversible step increase, just prior to crystallization on heating, which deviates from the typical behavior of glasses, liquids, and crystals. An increase in pressure shifts the step to higher temperatures and suppresses crystallization, which reveals another reversible rise in kappa and C-p. These results show that increased molecular mobility in the glacial state increases and suggest reduced thermal resistance at boundaries or that the motions carry heat.

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-119282 (URN)10.1021/acs.jpcb.6b00271 (DOI)000372562000022 ()26916579 (PubMedID)
Funder
Swedish Research Council, 621-2012-3336
Available from: 2016-06-01 Created: 2016-04-15 Last updated: 2018-06-07Bibliographically approved
Organisations

Search in DiVA

Show all publications