Activation energies of the self-diffusion of HTO, 22Na+ and 36Cl− in a highly compacted argillaceous rock (Opalinus Clay)

Loon, Luc R. Van; Müller, Werner; Iijima, K.

doi:10.1016/j.apgeochem.2004.10.007

Cited by 51 publications

(17 citation statements)

References 23 publications

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“…First, we observed that the values of the pre-factor are larger than those typically observed for molecular vibrations (τ 0 ≈ 10 −14 -10 −12 s). Moreover, the activation energies are similar to those found for the self-diffusion of ions through water in argillaceous rock porous network [89]. It is worth noting that the values of the activation energy calculated by the dielectric loss tangent correspond to those obtained by the direct current analysis indicating a correlation between these quantities.…”

Section: Opc Opc/gnpssupporting

confidence: 77%

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Elucidation of Conduction Mechanism in Graphene Nanoplatelets (GNPs)/Cement Composite Using Dielectric Spectroscopy

Goracci

Dolado

2020

Materials

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Understanding the mechanisms that govern the conductive properties of multifunctional cement-materials is fundamental for the development of the new applications proposed to enhance the energy efficiency, safety and structural properties of smart buildings and infrastructures. Many fillers have been suggested to increase the electrical conduction in concretes; however, the processes involved are still not entirely known. In the present work, we investigated the effect of graphene nanoplatelets (1 wt% on the electrical properties of cement composites (OPC/GNPs). We found a decrease of the bulk resistivity in the composite associated to the enhancement of the charge transport properties in the sample. Moreover, the study of the dielectric properties suggests that the main contribution to conduction is given by water diffusion through the porous network resulting in ion conductivity. Finally, the results support that the increase of direct current in OPC/GNPs is due to pore refinement induced by graphene nanoplatelets.

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Section: Opc Opc/gnpssupporting

confidence: 77%

“…Materials 2020, 13, x FOR PEER REVIEW 9 of 14 water in argillaceous rock porous network [89]. It is worth noting that the values of the activation energy calculated by the dielectric loss tangent correspond to those obtained by the direct current analysis indicating a correlation between these quantities.…”

Section: Opc Opc/gnpsmentioning

confidence: 58%

Elucidation of Conduction Mechanism in Graphene Nanoplatelets (GNPs)/Cement Composite Using Dielectric Spectroscopy

Goracci

Dolado

2020

Materials

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“…Radiotracers (including tritium) have been used previously to probe diffusion within micropores [ Smit et al , 1978, 1981]. Tritium diffusive transport has also been used as a means of determining total porosity in sedimentary rock and compacted clay systems [ García‐Gutiérrez et al , 2001; Van Loon et al , 2005], where in at least one example, the authors were able to resolve different types of porosity based on diffusion rate [ Van Loon and Jakob , 2005]. To our knowledge, however, ours is the first application of a generalized batch method for the determination of intragranular pore volume and surface area.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the intragranular water regime within subsurface sediments: Pore volume, surface area, and mass transfer limitations

Hay

Stoliker

Davis

et al. 2011

Water Resources Research

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[1] Although ''intragranular'' pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uraniumcontaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted with tracers in artificial groundwater, followed by a replacement of bulk solution with tracer-free groundwater and the monitoring of tracer release. From these data, intragranular pore volumes were calculated and mass transfer rates were quantified using a multirate first-order mass transfer model. Tritium-hydrogen exchange on surface hydroxyls was accounted for by conducting additional tracer experiments on sediment that was vacuum dried after reaction. The complementary (''wet'' and ''dry'') techniques allowed for the simultaneous determination of intragranular porosity and surface area using tritium. The Hanford 300A samples exhibited intragranular pore volumes of $1% of the solid volume and intragranular surface areas of $20%-35% of the total surface area. Analogous experiments using bromide ion as a tracer yielded very different results, suggesting very little penetration of bromide into the intragranular porosity.

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“…Van Loon et al (2005b) studied the effect of temperature on the diffusion of Hto, 36 Cl -and 22 na + in opalinus Clay. the increase of the effective diffusion coefficient could not be described by the Stokes-Einstein relationship (Li and Gregory, 1974) based on the temperature dependency of the viscosity of bulk water, indicating that the confined water in OPA has properties slightly different from bulk water.…”

confidence: 99%

Studying radionuclide migration on different scales: the complementary roles of laboratory and in situ experiments

Loon

Glaus

Ferry

et al. 2012

Radionuclide Behaviour in the Natural Environment

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Activation energies of the self-diffusion of HTO, 22Na+ and 36Cl− in a highly compacted argillaceous rock (Opalinus Clay)

Cited by 51 publications

References 23 publications

Elucidation of Conduction Mechanism in Graphene Nanoplatelets (GNPs)/Cement Composite Using Dielectric Spectroscopy

Elucidation of Conduction Mechanism in Graphene Nanoplatelets (GNPs)/Cement Composite Using Dielectric Spectroscopy

Characterization of the intragranular water regime within subsurface sediments: Pore volume, surface area, and mass transfer limitations

Studying radionuclide migration on different scales: the complementary roles of laboratory and in situ experiments

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