umu.sePublikasjoner
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Cohesive vibrational and structural depiction of intercalated water in montmorillonite
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.ORCID-id: 0000-0002-3830-7820
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.ORCID-id: 0000-0003-3927-6197
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.ORCID-id: 0000-0003-4954-6461
2018 (engelsk)Inngår i: ACS Earth and Space Chemistry, E-ISSN 2472-3452, Vol. 2, nr 1, s. 38-47Artikkel i tidsskrift (Fagfellevurdert) 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.

sted, utgiver, år, opplag, sider
American Chemical Society (ACS), 2018. Vol. 2, nr 1, s. 38-47
Emneord [en]
adsorption, montmorillonite, vibration spectroscopy, water vapor, X-ray diffraction
HSV kategori
Identifikatorer
URN: urn:nbn:se:umu:diva-143020DOI: 10.1021/acsearthspacechem.7b00103ISI: 000423141600005OAI: oai:DiVA.org:umu-143020DiVA, id: diva2:1166189
Tilgjengelig fra: 2017-12-14 Laget: 2017-12-14 Sist oppdatert: 2018-06-09bibliografisk kontrollert
Inngår i avhandling
1. Thin water and ice films on minerals: a molecular level study
Åpne denne publikasjonen i ny fane eller vindu >>Thin water and ice films on minerals: a molecular level study
2018 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
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.

sted, utgiver, år, opplag, sider
Umeå: Umeå University, 2018. s. 67
Emneord
water, ice, cryosalt, minerals, rocks, atmosphere, Dynamic Vapour Sorption, FTIR, cryo-FESEM
HSV kategori
Forskningsprogram
fysikalisk kemi
Identifikatorer
urn:nbn:se:umu:diva-145836 (URN)978-91-7601-868-2 (ISBN)
Disputas
2018-04-13, Stora hörsalen KB.E3.03, KBC-Huset, Umeå, 09:30 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2018-03-23 Laget: 2018-03-19 Sist oppdatert: 2018-06-09bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekst

Personposter BETA

Yeşilbaş, MerveHolmboe, MichaelBoily, Jean-François

Søk i DiVA

Av forfatter/redaktør
Yeşilbaş, MerveHolmboe, MichaelBoily, Jean-François
Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 295 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf