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Yeşilbaş, Merve
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Publications (9 of 9) Show all publications
Yeşilbaş, M., Holmboe, M. & Boily, J.-F. (2019). Residence times of nanoconfined CO2 in layered aluminosilicates. Environmental Science: Nano, 6(1), 146-151
Open this publication in new window or tab >>Residence times of nanoconfined CO2 in layered aluminosilicates
2019 (English)In: Environmental Science: Nano, ISSN 2051-8153, Vol. 6, no 1, p. 146-151Article in journal (Refereed) Published
Abstract [en]

Nanoconfinement of CO2 in layered aluminosilicates contributes to the capture and release of this greenhouse gas in soils. In this work, we show that the residence times of CO2 in montmorillonite are lowered by 15 min for each 1 degrees C increment in temperature during venting. Molecular simulations showed that activation energies of release are no more than half of the experimentally derived value of 34 kJ mol(-1). This raised the possibility of additional processes limiting CO2 mobility in real materials, including (chemi)sorption at reactive sites or frayed edges or defects. The residence times (approximate to 1616 min at -50 degrees C to approximate to 6 min at 60 degrees C) for some of the driest (approximate to 1.4 mmol H2O per g) montmorillonites that can be produced at ambient temperatures are readily lowered by inclusion of additional water. They are, in turn, prolonged again as the water content and interlayer spacing become smaller through venting. These efforts showed that soil-building clay minerals will lose their propensity to dynamically exchange CO2 as temperatures continue to rise, yet they may retain CO2 more efficiently in cold seasons as soils will become depleted in moisture content.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Environmental Sciences Geochemistry
Identifiers
urn:nbn:se:umu:diva-157978 (URN)10.1039/c8en01156g (DOI)000461698700010 ()
Available from: 2019-04-10 Created: 2019-04-10 Last updated: 2019-04-10Bibliographically approved
Yeşilbaş, M., Holmboe, M. & Boily, J.-F. (2018). Cohesive vibrational and structural depiction of intercalated water in montmorillonite. ACS Earth and Space Chemistry, 2(1), 38-47
Open this publication in new window or tab >>Cohesive vibrational and structural depiction of intercalated water in montmorillonite
2018 (English)In: ACS Earth and Space Chemistry, E-ISSN 2472-3452, Vol. 2, no 1, p. 38-47Article in journal (Refereed) Published
Abstract [en]

The vibrational spectral profiles of Na- and Ca-montmorillonite (MMT) of controlled water layer populations (nW) was extracted by chemometric analysis of new Fourier transform infrared (FTIR) spectroscopy data and validated by mixed-layer modeling of previously published X-ray diffraction data. These efforts resolved FTIR spectral profiles of 0W, 1W, and 2W interlayers, which can now be used to explore the distinct hydration states of MMT. These spectral profiles reflect water populations organized around interlayer cations (Na+, Ca2+), interacting with siloxane groups of the basal face of the interlayer, and with other bound and “free” water molecules. This cohesive description of water-bearing clays provides the link needed to relate vibrational to structural attributes of these geochemically important materials.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
adsorption, montmorillonite, vibration spectroscopy, water vapor, X-ray diffraction
National Category
Geochemistry
Identifiers
urn:nbn:se:umu:diva-143020 (URN)10.1021/acsearthspacechem.7b00103 (DOI)000423141600005 ()
Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2018-06-09Bibliographically approved
Yeşilbaş, M., Lee, C. C. & Boily, J.-F. (2018). Ice and cryosalt formation in saline microporous clay gels. ACS Earth and Space Chemistry, 2(4), 314-319
Open this publication in new window or tab >>Ice and cryosalt formation in saline microporous clay gels
2018 (English)In: ACS Earth and Space Chemistry, ISSN 2472-3452, Vol. 2, no 4, p. 314-319Article in journal (Refereed) Published
Abstract [en]

Hydrated clay minerals that are common to Earth’s atmosphere and terrestrial and aquatic environments can form gels that host saline solutions. Using cryogenic electron microscopy and vibration spectroscopy, we show that saline gels of montmorillonite frozen at < −90 °C host elongated hexagonal ice (Ih) microcrystals embedded in a network of honeycomb micropores. Freezing segregates salts into walls of aggregated clay nanoparticles sharing face-to-face contacts. Above ∼ −50 °C, clay gels that are sufficiently dense (≫10 g/L) and flexible (Na-exchanged montmorillonite) also host the cryosalt mineral hydrohalite (NaCl·2H2O), either co-existing or entirely replacing Ih in the gels. Hydrohalite does not form in gels of low-density (<10 g/L) or rigid (Ca-exchange montmorillonite) clay particles. These results suggest that hydrohalite forms in expandable clay gels that are sufficiently dense and flexible to retain saline solutions within their walls, possibly through interparticle capillary and hydration forces. These forces effectively oppose water diffusion to growing ice microcrystals within micropores, thus prolonging the lifetime of hydrohalite within these hydrated clay gels. Our findings tie the fate of ice and cryosalt nucleation and growth to the water-retention capability of expandable clay gels.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
montmorillonite, hydrohalite, ice, vibration spectroscopy, cryo-SEM
National Category
Geosciences, Multidisciplinary
Research subject
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-145727 (URN)10.1021/acsearthspacechem.7b00134 (DOI)000430896000003 ()2-s2.0-85045729913 (Scopus ID)
Funder
Swedish Research Council, 2016-03808
Available from: 2018-03-15 Created: 2018-03-15 Last updated: 2018-09-25Bibliographically approved
Yeşilbaş, M. (2018). Thin water and ice films on minerals: a molecular level study. (Doctoral dissertation). Umeå: Umeå University
Open this publication in new window or tab >>Thin water and ice films on minerals: a molecular level study
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Minerals in Earth’s crust and suspended in the atmosphere form water or ice films as thin as a few nanometers to as thick as a few micrometers, and beyond. Mineral-bound water and ice films in terrestrial systems (e.g. vadose zones, permafrosts) can impact the bio(geo)chemistry of nutrients and contaminants, water cycling, as well as possible land-air exchanges in terrestrial environments. In the atmosphere, films are tied to clouds and rain formation, and can influence the absorption and scattering of solar radiation of dust mineral aerosols. Water films are, at the same time, of interest to technology. They are even of interest in the study of asteroids, comets, and planet Mars. Still, their formation on the various types of minerals common to the environment is misunderstood.

The aim of this thesis is to gain fundamental insight on the roles that minerals play on forming and stabilising thin water and ice films. This work is separated in two parts, with Part A associated with Papers I-II, and Part B with Papers III-V of the appendix of this thesis.

In Part A of this work (Papers I-II), water loadings and vibrational signatures of thin water films were collected on 21 different minerals (metal oxides, silicates, carbonates) relevant to terrestrial environments, atmosphere and perhaps outer-space. Measurements were made on minerals of varied (i) composition, (ii) structure, (iii) morphology, (iv) particle size and (v) surface roughness. Loadings, measured by a microgravimetric Dynamic Vapour Sorption technique, were of a few monolayers in sub-micrometer-sized particles but of several hundreds to thousands of water layers in micrometer-sized particles (Paper I). This was seen in the Fourier Transform Infrared (FTIR) spectra of sub-micrometer-sized particles with different hydrogen bonding environments than liquid water. Micrometer-sized particles formed liquid-like films regardless of the mineral. Similar observations were made in the spectra of the thinnest water films remaining on these minerals after long periods of sublimation of ice overcoatings at sub-freezing temperatures (Paper II).

In Part B of this work (Papers III-V), focus on the expandable clay mineral montmorillonite was made to study (i) intercalated water, (ii) ice and cryosalt formation inside microporous gels, and (iii) its interactions with intercalated CO2.  FTIR extracted spectral components reflecting interlayer hydration states of ~0W, 1W and 2W monolayers of water (Paper III). Thermal dehydration/dehydroxylation experiments showed that the driest forms of montmorillonite strongly retained low levels of crystalline water in its structure.  FTIR also showed that frozen wet gels of montmorillonite form ice and the cryosalt mineral hydrohalite. Ice was seen in rigid gels and aggregated compact particles, as well as low particle density with low salt content. In contrast, concentrated (>> 10 g/L) saline gels host hydrohalite, probably between and/or near aggregated clay particle walls. Field-Emission Cryogenic Scanning Electron Microscopy showed that ice microcrystals form in micropores of the gels (Paper IV). Finally, release rates of CO2 trapped in interlayers of montmorillonite, monitored by FTIR spectroscopy, were larger in the presence of 1-2W. The activation energy of CO2 release from~0W montmorillonite (34 kJ/mol) is comparable to other mineral surfaces. This study highlights that the most stabilised CO2 occur in of dry and cold conditions.

This thesis will hopefully serve as a springboard for further work exploring the chemistry and physics of water and ice films at minerals surfaces. It should contribute to improve our understanding of the geochemistry of Earth’s soils, processes in the atmosphere, and even of space chemistry.

Place, publisher, year, edition, pages
Umeå: Umeå University, 2018. p. 67
Keywords
water, ice, cryosalt, minerals, rocks, atmosphere, Dynamic Vapour Sorption, FTIR, cryo-FESEM
National Category
Physical Chemistry Geosciences, Multidisciplinary Inorganic Chemistry
Research subject
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-145836 (URN)978-91-7601-868-2 (ISBN)
Public defence
2018-04-13, Stora hörsalen KB.E3.03, KBC-Huset, Umeå, 09:30 (English)
Opponent
Supervisors
Available from: 2018-03-23 Created: 2018-03-19 Last updated: 2018-06-09Bibliographically approved
Lucas, M., Yeşilbaş, M., Shchukarev, A. & Boily, J.-F. (2018). X-ray photoelectron spectroscopy of fast-Frozen hematite colloids in aqueous solutions. 6. Sodium halide (F–, Cl–, Br–, I–) ion binding on microparticles. Langmuir, 34(45), 13497-13504
Open this publication in new window or tab >>X-ray photoelectron spectroscopy of fast-Frozen hematite colloids in aqueous solutions. 6. Sodium halide (F–, Cl–, Br–, I–) ion binding on microparticles
2018 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 45, p. 13497-13504Article in journal (Refereed) Published
Abstract [en]

Electrolyte ion binding at mineral surfaces is central to the generation of surface charge and key to electric double-layer formation. X-ray photoelectron spectroscopy of fast-frozen (−170 °C) mineral wet pastes provides a means to study weakly bound electrolyte ions at the mineral/water interface. In this study, we build upon a series of articles devoted to ion binding at hematite (α-Fe2O3) particle surfaces to resolve the nature of sodium halide ion binding. Measurements on micron-sized hematite particles terminated by the charged and amphoteric (012) and the relatively uncharged (001) faces point to the formation of salt loadings of similar composition to those of cryosalts of NaCl, NaBr, NaI, and NaF. These coatings could be likened to those of the better-known hydrohalite (NaCl·2H2O) phase, one that typically forms under concentrated (≫0.1 M) aqueous solutions of NaCl under freezing conditions. As we have previously shown that these reaction products do not occur in nanosized hematite particles, our work points to the involvement of the basal (001) face and/or the juxtaposition of these faces in packed tabular microparticles of hematite (1–3 μm in width) in stabilizing these cryosalts. One possible formation pathway involves first-layer Na+ and Cl– ions serving as an anchoring layer for a topotactic-like growth of amorphous to low-crystalline salt hydrates at the (001) face. Thus, by contrasting reaction products of four sodium halides at surfaces of tabular microparticles of hematite, this work revealed the formation of cryosalt-like solids. The formation of such solids may have especially important ramifications to ice nucleation mechanisms in the atmosphere, as well as in saline permafrosts on Earth and on planet Mars where salt-laden mineral particles prevail.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-154485 (URN)10.1021/acs.langmuir.8b01507 (DOI)000450695000005 ()
Funder
Carl Tryggers foundation Swedish Research Council, 2017-03808
Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2018-12-19Bibliographically approved
Yeşilbaş, M. & Boily, J.-F. (2016). Particle Size Controls on Water Adsorption and Condensation Regimes at Mineral Surfaces. Scientific Reports, 6, Article ID 32136.
Open this publication in new window or tab >>Particle Size Controls on Water Adsorption and Condensation Regimes at Mineral Surfaces
2016 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 32136Article in journal (Refereed) Published
Abstract [en]

Atmospheric water vapour interacting with hydrophilic mineral surfaces can produce water films of various thicknesses and structures. In this work we show that mineral particle size controls water loadings achieved by water vapour deposition on 21 contrasting mineral samples exposed to atmospheres of up to ~16 Torr water (70% relative humidity at 25 °C). Submicrometer-sized particles hosted up to ~5 monolayers of water, while micrometer-sized particles up to several thousand monolayers. All films exhibited vibrational spectroscopic signals akin to liquid water, yet with a disrupted network of hydrogen bonds. Water adsorption isotherms were predicted using models (1- or 2- term Freundlich and Do-Do models) describing an adsorption and a condensation regime, respectively pertaining to the binding of water onto mineral surfaces and water film growth by water-water interactions. The Hygroscopic Growth Theory could also account for the particle size dependence on condensable water loadings under the premise that larger particles have a greater propensity of exhibiting of surface regions and interparticle spacings facilitating water condensation reactions. Our work should impact our ability to predict water film formation at mineral surfaces of contrasting particle sizes, and should thus contribute to our understanding of water adsorption and condensation reactions occuring in nature.

National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-124995 (URN)10.1038/srep32136 (DOI)000381967600001 ()27561325 (PubMedID)
Funder
Swedish Research Council, 2012-2976
Available from: 2016-09-01 Created: 2016-09-01 Last updated: 2018-06-07Bibliographically approved
Yeşilbaş, M. & Boily, J.-F. (2016). Thin Ice Films at Mineral Surfaces [Letter to the editor]. Journal of Physical Chemistry Letters, 7(14), 2849-2855
Open this publication in new window or tab >>Thin Ice Films at Mineral Surfaces
2016 (English)In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 7, no 14, p. 2849-2855Article in journal, Letter (Refereed) Published
Abstract [en]

Ice films formed at mineral surfaces are of widespread occurrence in nature and are involved in numerous atmospheric and terrestrial processes. In this study, we studied thin ice films at surfaces of 19 synthetic and natural mineral samples of varied structure and composition. These thin films were formed by sublimation of thicker hexagonal ice overlayers mostly produced by freezing wet pastes of mineral particles at -10 and -50 °C. Vibration spectroscopy revealed that thin ice films contained smaller populations of strongly hydrogen-bonded water molecules than in hexagonal ice and liquid water. Thin ice films at the surfaces of the majority of minerals considered in this work [i.e., metal (oxy)(hydr)oxides, phyllosilicates, silicates, volcanic ash, Arizona Test Dust] produced intense O-H stretching bands at ∼3400 cm(-1), attenuated bands at ∼3200 cm(-1), and liquid-water-like bending band at ∼1640 cm(-1) irrespective of structure and composition. Illite, a nonexpandable phyllosilicate, is the only mineral that stabilized a form of ice that was strongly resilient to sublimation in temperatures as low as -50 °C. As mineral-bound thin ice films are the substrates upon which ice grows from water vapor or aqueous solutions, this study provides new constraints from which their natural occurrences can be understood.

Place, publisher, year, edition, pages
Washington: American Chemical Society (ACS), 2016
National Category
Chemical Sciences
Identifiers
urn:nbn:se:umu:diva-124991 (URN)10.1021/acs.jpclett.6b01037 (DOI)000380415400035 ()
Funder
Swedish Research Council, 2012-2976
Available from: 2016-09-01 Created: 2016-09-01 Last updated: 2018-06-07Bibliographically approved
Boily, J.-F., Yesilbas, M., Uddin, M. M. M., Baiqing, L., Trushkina, Y. & Salazar-Alvarez, G. (2015). Thin Water Films at Multifaceted Hematite Particle Surfaces. Langmuir, 31(48), 13127-13137
Open this publication in new window or tab >>Thin Water Films at Multifaceted Hematite Particle Surfaces
Show others...
2015 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 31, no 48, p. 13127-13137Article in journal (Refereed) Published
Abstract [en]

Mineral surfaces exposed to moist air stabilize nanometer- to micrometer-thick water films. This study resolves the nature of thin water film formation at multifaceted hematite (alpha-Fe2O3) nanoparticle surfaces with crystallographic faces resolved by selected area electron diffraction. Dynamic vapor adsorption (DVA) in the 0-19 Torr range at 298 K showed that these particles stabilize water films consisting of up to 4-5 monolayers. Modeling of these data predicts water loadings in terms of an "adsorption regime" (up to 16 H2O/nm(2)) involving direct water binding to hematite surface sites, and of a "condensation regime" (up to 34 H2O/nm(2)) involving water binding to hematite-bound water nanodusters. Vibration spectroscopy identified the predominant hematite surface hydroxo groups (-OH, mu-OH, mu(3)-OH) through which first layer water molecules formed hydrogen bonds, as well as surface iron sites directly coordinating water molecules (i.e., as geminal eta-(OH2)(2) sites). Chemometric analyses of the vibration spectra also revealed a strong correspondence in the response of hematite surface hydroxo groups to DVA-derived water loadings. These findings point to a near-saturation of the hydrogen-bonding environment of surface hydroxo groups at a partial water vapor pressure of similar to 8 Torr (similar to 40% relative humidity). Classical molecular dynamics (MD) resolved the interfacial water structures and hydrogen bonding populations at five representative crystallographic faces expressed in these nanoparticles. Simulations of single oriented slabs underscored the individual roles of all (hydro)oxo groups in donating and accepting hydrogen bonds with first layer water in the "adsorption regime". These analyses pointed to the preponderance of hydrogen bond-donating -OH groups in the stabilization of thin water films. Contributions of mu-OH and mu(3)-OH groups are secondary, yet remain essential in the stabilization of thin water films. MD simulations also helped resolve crystallographic controls on water water interactions occurring in the "condensation regime". Water water hydrogen bond populations are greatest on the (001) face, and decrease in importance in the order (001) > (012) approximate to (110) > (014) >> (100). Simulations of a single (similar to 5 nm x similar to 6 nm x similar to 6 nm) nanometric hematite particle terminated by the (001), (110), (012), and (100) faces also highlighted the key roles that sites at particle edges play in interconnecting thin water films grown along contiguous crystallographic faces. Hydroxo water hydrogen bond populations showed that edges were the preferential loci of binding. These simulations also suggested that equilibration times for water binding at edges were slower than on crystallographic faces. In this regard, edges, and by extension roughened surfaces, are expected to play commanding roles in the stabilization of thin water films. Thus, in focusing on the properties of nanometric-thick water layers at hematite surfaces, this study revealed the nature of interactions between water and multifaced particle surfaces. Our results pave the way for furthering our understanding of mineral-thin water film interfacial structure and reactivity on a broader range of materials.

National Category
Materials Chemistry Chemical Sciences
Identifiers
urn:nbn:se:umu:diva-113845 (URN)10.1021/acs.langmuir.5b03167 (DOI)000366223300009 ()26559158 (PubMedID)
Available from: 2016-03-14 Created: 2016-01-04 Last updated: 2018-06-07Bibliographically approved
Yeşilbaş, M., Holmboe, M. & Boily, J.-F.Trapping and release of atmospheric carbon dioxide by clays.
Open this publication in new window or tab >>Trapping and release of atmospheric carbon dioxide by clays
(English)Manuscript (preprint) (Other academic)
National Category
Geochemistry
Identifiers
urn:nbn:se:umu:diva-145863 (URN)
Available from: 2018-03-20 Created: 2018-03-20 Last updated: 2018-06-09
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