Effect of CaO/SiO2 molar ratio on the electrical and physical properties of basaltic glass materials

Abstract

The effect of CaO∖SiO 2 molar ratio on the electrical properties of some glass materials was examined, using the impedance spectroscopy, at different frequency ranges, from 100 Hz up to 5 MHz. Also, a trial was accomplished to study the influence of CaO∖SiO 2 molar ratio on some physical properties such as density, micro-hardness and bending strength. Six glass batches, based on Sinai basaltic rocks and bypass cement dust, were prepared with different CaO/SiO 2 molar ratios (0.2–0.93 mol %). Accordingly, the electrical properties (conductivity dielectric constant and dielectric loss) of these samples show noticeable change. Electrical results show that the samples with relatively low (CaO/SiO 2 ) molar ratio have relatively higher electrical conductivity, compared to the other samples with higher (CaO/SiO 2 ) molar ratios, at different frequencies. Also, at the same time, the bending strength and Vickers micro-hardness show a gradual increase from 56 to 118 MPa and from 4020 to 6120 MPa, respectively, with decreasing CaO/SiO 2 molar ratio. The density of the samples shows a successive increase from 2.79 to 2.96 gm/cm 3 with the successive additions of bypass cement dust.

Formulation of Compressed Earth Blocks Stabilized by Glass Waste Activated with NaOH Solution

“…Sediments with a relatively low molar ratio (CaO/SiO 2 ) have a relatively high electrical conductivity. In addition, their flexural strength gradually increases with a decrease in the CaO/SiO 2 molar ratio [49]. Loss of ignition (LOI) is the result of the calcination of powders up to 1000 • C. The high LOI was related to the presence of carbonates and the water evaporated by heat treatment.…”

Structural, electrical and photocatalytic properties of iron-containing soda-lime aluminosilicate glass and glass-ceramics

“…Nishida et al [22] reported that glass prepared using fly ash shows an electrical conductivity from 10 -8 to 10 -6 S cm -1 due to electron hopping from less distorted Fe II O6 octahedra to distorted Fe III O4 tetrahedra. Khater et al [23] studied the effect of CaO/SiO2 (0.2-0.93 mol %) on the electrical properties of some glass materials. The samples with relatively low CaO/SiO2 molar ratios have higher electrical conductivity, compared to the other samples with higher CaO/SiO2 molar ratios.…”

Kaolinite under pressure at audio frequency range and its electrical features

“…The diffused double layer charge carriers are separated from the kaolinite particles by the well-known stern (solid) double layer (Grant 1958;Schurr 1964). The ions of the diffused double layer are weakly attached to the kaolinite particle surface (Gomaa et al 2019, Khater et al 2019a, 2019bMelegy et al 2019;Gomaa 2020;Gomaa and Kenawy 2020). These diffuse double layer ions can move in the water film (humidity) surrounding the particles.…”

“…The data suggest two kinds of conduction in these rocks: (1) conduction along cracks (at a pressure of a few kilobars) as in granite (Abou El-Anwar and Gomaa 2013, and (2) volume and surface conduction along a network of pores that continue over the whole pressure range (remaining open for relatively higher pressure), as in sand. A rock saturated with drinking water has a surface conduction 10 to 20 times greater than conduction mechanisms from pore volumes (Gomaa et al 2019, Khater et al 2019a, 2019bMelegy et al 2019;Gomaa 2020;Gomaa and Kenawy 2020). Rocks of minute porosity under low pressure may show a transition behaviour from a resistive condition to a conductive condition.…”