Electrical conductance of a sandstone partially saturated with varying concentrations of NaCl solutions

Umezawa, Ryosuke; Nishiyama, Naoki; Katsura, Masahiro; Nakashima, Satoru

doi:10.1093/gji/ggx092

Cited by 6 publications

(2 citation statements)

References 18 publications

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“…The surface conductivity Σ s (S) of silica particles was calculated from the following equation [8]:…”

Section: B Surface Conductivity Of Water Film On Silica Nanoparticlesmentioning

confidence: 99%

“…In these pores, solid/water/air interfaces are present like the above materials under normal relative humidity (RH) conditions. The electrical conductivity in these unsaturated rocks suggest that surface conductivity changes with decreasing degrees of water saturation and is different from the conductivity in bulk pore water [8]. It should be noted that surface conductivity through wetted mineral grain networks in rocks and soils can be a good measure of water connectivity and material transport properties (permeability, diffusivity) [9,10].…”

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

Electrical Conductivity at Surfaces of Silica Nanoparticles with Adsorbed Water at Various Relative Humidities

Umezawa

Katsura

Nakashima

2018

e-J. Surf. Sci. Nanotech.

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Electrical conductivity of silica nanoparticles deposited on electrodes from colloidal suspension were measured under controlled relative humidity (RH). The electrical conductivity values at 1 kHz increased with increasing RH. Amounts of water adsorbed on silica nanoparticles were measured by quartz crystal microbalance (QCM) and they also increased with increasing RH. An empirical power law relation was observed between the reported surface conductivity and RH data for a silica glass. By applying this relation to the silica nanoparticles, the water film thicknesses are estimated to be from 0.08 nm to 0.23 nm. The corresponding specific surface area (SSA) becomes smaller (102 m 2 g −1) than the reported value (215 m 2 g −1), indicating aggregation of the nanoparticles. In fact, aggregated rod-like structures were observed under electron and laser scanning microscopy. The electrical conduction of deposited silica nanoparticles under various RH can be understood by surface conduction in thin water films adsorbed on the nanoparticles.

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“…The surface conductivity Σ s (S) of silica particles was calculated from the following equation [8]:…”

Section: B Surface Conductivity Of Water Film On Silica Nanoparticlesmentioning

confidence: 99%