The influence of exchangeable alkali cations on glucose uptake, interlayer reorganization and ionic transport was investigated in homoionic Wyoming montmorillonite exchanged with the complete alkali series (Li+, Na+, K+, Rb+ and Cs+). Glucose adsorption was rapid during the initial stage and reached equilibrium after ∼6 h. Under the investigated conditions, the equilibrium uptake was highest for the Li- and Cs-exchanged forms, whereas the Na-exchanged form showed the lowest adsorption amount. X-ray diffraction, differential thermal analysis and Fourier-transform infrared spectroscopy collectively support partial accommodation of glucose within the interlayer region without major disruption of the aluminosilicate framework, although the magnitude of the structural response depended strongly on the exchangeable cation. The largest basal expansion was observed for the Li- and Na-exchanged forms, showing that interlayer opening does not directly parallel adsorption capacity across the alkali series. Broadband impedance spectroscopy further indicates thermally activated ionic transport and a marked cation dependence of both direct current (DC) conductivity and activation energy after glucose loading. In particular, glucose adsorption altered the conduction environment more strongly in the Li- and Na-exchanged systems than in the K-, Rb- and Cs-exchanged forms under the same thermal conditioning. Taken together, the results suggest that glucose uptake, interlayer expansion and ionic transport are governed by coupled effects involving cation hydration, interlayer accessibility and local structural organization rather than by a single cation property alone. This comparative dataset provides a basis for understanding how exchangeable cations regulate saccharide–clay interactions in montmorillonite.

The brick production industry faces increasing environmental pressure due to high energy demands during firing, necessitating the optimization of firing conditions. This study investigates an eco-friendly stepped firing process as a sustainable alternative to conventional direct heat treatment using clayey raw materials from the Ouled Mansour area, north-east Morocco. To evaluate this approach, raw materials were characterized using X-ray diffraction, X-ray fluorescence, infrared spectroscopy, simultaneous thermal analysis, Atterberg limits and particle-size distribution analysis. Brick specimens were then prepared and fired under both conventional and stepped heating processes. Their thermophysical properties (thermal conductivity, thermal diffusivity, porosity, water absorption and density) and compressive strength were assessed. Non-destructive tests (ultrasonic pulse velocity and Schmidt hammer tests) together with mineralogical and microstructural analyses were also performed. The stepped firing process reduces porosity and defects, thereby increasing the ultrasonic pulse velocity from 3197 to 3508 m s–1 and improving compressive strength by up to 21%. Thermal conductivity and density slightly increase, from 0.57 to 0.58 W mK–1 and from 1.60 to 1.62 g cm–3 at 770°C, respectively. The proposed eco-friendly firing process enhances the physico-mechanical performance of bricks while supporting their energy-efficient production, with potential reductions in energy consumption during both manufacturing and the building service life.

In this paper we describe a simple method for determining the aspect ratio (AR) of clay mineral particles by measuring the electrical conductivity of randomly orientated suspensions as a function of volume fraction. The AR of industrial clay mineral products is a key parameter in defining their suitability for a range of applications and in differentiating them from other minerals, but there is no single, well-established technique for measuring it. Most researchers and producers rely on either microscopy or calculations based on particle-size distributions measured by two techniques with different sensitivities to particle dimensions. The effect of particle AR on the electrical conductivity of particle suspensions has been known for over a century and has been used previously to measure an average AR, but this has not become an established method. In this work, the theory of Dukhin and Derjaguin is used to calculate the average particle AR, which is independent of particle size. Using this method, the AR of a range of kaolin, talc and mica samples is measured and compared with values from other techniques. AR measured by the method described is shown to correlate well with the effects of clay minerals on the stiffness of filled polyolefins, as expected from theory.