X-ray studies on the nano- and microscale anisotropy in compacted clays: Comparison of bentonite and purified calcium montmorillonite

J-P Suuronen (Corresponding Author), Michal Matusewicz, Markus Olin, R Serimaa

    Research output: Contribution to journalArticleScientificpeer-review

    9 Citations (Scopus)

    Abstract

    Exceptional water retention properties make compacted clays and clayrocks attractive materials in waste management applications, e.g. as buffer materials and barrier formations for radionuclide release in geological disposal of spent nuclear fuel elements. Consisting of particles with a very high aspect ratio, clay materials exhibit significant structural anisotropy with potential implications on their performance. In this work, the micron-scale and nanometer-scale anisotropy in compacted calcium montmorillonite and MX-80 bentonite were investigated and quantified under varying humidity conditions; the utilized novel experimental method combines X-ray microtomography (XMT) and small-angle X-ray diffraction to near-simultaneously characterize both the micron-scale 3D morphology and mineralogical properties such as clay platelet spacing in platelet stacks (tactoids) and tactoid orientation. Sedimentation during the purification process and lack of accessory minerals were found to induce much stronger orientation in purified Ca-montmorillonite as compared to the MX-80. In highly anisotropic samples, the orientation of microcracks visualized with XMT under low humidity conditions was found to correlate with the local orientation of clay tactoids measured with X-ray diffraction. The proposed experimental method can be applied to a wide range of similar materials, such as shales or samples from clayrock formations.
    Original languageEnglish
    Pages (from-to)401-408
    Number of pages7
    JournalApplied Clay Science
    Volume101
    DOIs
    Publication statusPublished - 2014
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    Bentonite
    bentonite
    montmorillonite
    Anisotropy
    anisotropy
    calcium
    Calcium
    clay
    X rays
    Platelets
    Atmospheric humidity
    humidity
    X-ray diffraction
    Nuclear fuel elements
    X ray diffraction
    accessory mineral
    Spent fuels
    microcrack
    Accessories
    Microcracks

    Keywords

    • Anisotropy
    • Bentonite
    • Compaction
    • Diffraction
    • Microtomography
    • Montmorillonite

    Cite this

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    title = "X-ray studies on the nano- and microscale anisotropy in compacted clays: Comparison of bentonite and purified calcium montmorillonite",
    abstract = "Exceptional water retention properties make compacted clays and clayrocks attractive materials in waste management applications, e.g. as buffer materials and barrier formations for radionuclide release in geological disposal of spent nuclear fuel elements. Consisting of particles with a very high aspect ratio, clay materials exhibit significant structural anisotropy with potential implications on their performance. In this work, the micron-scale and nanometer-scale anisotropy in compacted calcium montmorillonite and MX-80 bentonite were investigated and quantified under varying humidity conditions; the utilized novel experimental method combines X-ray microtomography (XMT) and small-angle X-ray diffraction to near-simultaneously characterize both the micron-scale 3D morphology and mineralogical properties such as clay platelet spacing in platelet stacks (tactoids) and tactoid orientation. Sedimentation during the purification process and lack of accessory minerals were found to induce much stronger orientation in purified Ca-montmorillonite as compared to the MX-80. In highly anisotropic samples, the orientation of microcracks visualized with XMT under low humidity conditions was found to correlate with the local orientation of clay tactoids measured with X-ray diffraction. The proposed experimental method can be applied to a wide range of similar materials, such as shales or samples from clayrock formations.",
    keywords = "Anisotropy, Bentonite, Compaction, Diffraction, Microtomography, Montmorillonite",
    author = "J-P Suuronen and Michal Matusewicz and Markus Olin and R Serimaa",
    year = "2014",
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    language = "English",
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    X-ray studies on the nano- and microscale anisotropy in compacted clays : Comparison of bentonite and purified calcium montmorillonite. / Suuronen, J-P (Corresponding Author); Matusewicz, Michal; Olin, Markus; Serimaa, R.

    In: Applied Clay Science, Vol. 101, 2014, p. 401-408.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - X-ray studies on the nano- and microscale anisotropy in compacted clays

    T2 - Comparison of bentonite and purified calcium montmorillonite

    AU - Suuronen, J-P

    AU - Matusewicz, Michal

    AU - Olin, Markus

    AU - Serimaa, R

    PY - 2014

    Y1 - 2014

    N2 - Exceptional water retention properties make compacted clays and clayrocks attractive materials in waste management applications, e.g. as buffer materials and barrier formations for radionuclide release in geological disposal of spent nuclear fuel elements. Consisting of particles with a very high aspect ratio, clay materials exhibit significant structural anisotropy with potential implications on their performance. In this work, the micron-scale and nanometer-scale anisotropy in compacted calcium montmorillonite and MX-80 bentonite were investigated and quantified under varying humidity conditions; the utilized novel experimental method combines X-ray microtomography (XMT) and small-angle X-ray diffraction to near-simultaneously characterize both the micron-scale 3D morphology and mineralogical properties such as clay platelet spacing in platelet stacks (tactoids) and tactoid orientation. Sedimentation during the purification process and lack of accessory minerals were found to induce much stronger orientation in purified Ca-montmorillonite as compared to the MX-80. In highly anisotropic samples, the orientation of microcracks visualized with XMT under low humidity conditions was found to correlate with the local orientation of clay tactoids measured with X-ray diffraction. The proposed experimental method can be applied to a wide range of similar materials, such as shales or samples from clayrock formations.

    AB - Exceptional water retention properties make compacted clays and clayrocks attractive materials in waste management applications, e.g. as buffer materials and barrier formations for radionuclide release in geological disposal of spent nuclear fuel elements. Consisting of particles with a very high aspect ratio, clay materials exhibit significant structural anisotropy with potential implications on their performance. In this work, the micron-scale and nanometer-scale anisotropy in compacted calcium montmorillonite and MX-80 bentonite were investigated and quantified under varying humidity conditions; the utilized novel experimental method combines X-ray microtomography (XMT) and small-angle X-ray diffraction to near-simultaneously characterize both the micron-scale 3D morphology and mineralogical properties such as clay platelet spacing in platelet stacks (tactoids) and tactoid orientation. Sedimentation during the purification process and lack of accessory minerals were found to induce much stronger orientation in purified Ca-montmorillonite as compared to the MX-80. In highly anisotropic samples, the orientation of microcracks visualized with XMT under low humidity conditions was found to correlate with the local orientation of clay tactoids measured with X-ray diffraction. The proposed experimental method can be applied to a wide range of similar materials, such as shales or samples from clayrock formations.

    KW - Anisotropy

    KW - Bentonite

    KW - Compaction

    KW - Diffraction

    KW - Microtomography

    KW - Montmorillonite

    U2 - 10.1016/j.clay.2014.08.015

    DO - 10.1016/j.clay.2014.08.015

    M3 - Article

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    SP - 401

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    JO - Applied Clay Science

    JF - Applied Clay Science

    SN - 0169-1317

    ER -