This study focuses on the synthesis of poly(3,4-dihydro-2H-pyran-alt-maleic anhydride) and poly(3,4-dihydro-2H-pyran-co-maleic anhydride-co-vinyl acetate) and their nanocomposites modified with organoammonium salts. The goal was to investigate the structural, dynamic mechanical and thermal properties of the polymers and nanocomposites, with a particular focus on the role of organoclay modification. In this study, bentonite was modified using alkyl ammonium salts with varying chain lengths (C14, C16 and C18). Ion-exchange processes led to the transformation of the character of bentonite from hydrophilic to hydrophobic, facilitating the formation of hybrid structures. Dynamic mechanical analysis, differential thermal analysis, differential scanning calorimetry and thermogravimetric analysis were used to characterize the viscoelastic and thermal properties of the polymers and their nanocomposites. The results showed that the incorporation of organoclay structures, particularly those modified with C18 alkyl groups, significantly improved the viscoelastic properties, with the greatest storage modulus being observed in the nanocomposites. The thermal analysis revealed that the nanocomposites exhibited a distinct three-step degradation process, unlike the copolymer, which underwent two-step degradation. Despite this difference, no significant improvement in thermal stability was observed in the nanocomposites compared to the copolymers. The study concludes that the incorporation of long-chain alkyl ammonium salts into bentonite and their use in copolymerization significantly impact the thermal and dynamic mechanical properties of the resulting nanocomposites. The modification of bentonite with C18 alkyl groups led to the most stable and dynamic mechanically robust nanocomposites, providing valuable insights into the role of organoclay modification in improving the performance of polymer-based nanocomposites.

A celadonitic clay deposit is located ∼40 km north-west of Yazlıca-Kütahya (Türkiye) and has promising reserves for ceramic production. To evaluate the potential use of this region, 10 representative clay samples were collected and characterized using X-ray diffraction (XRD), polarized-light microscopy (PM), X-ray fluorescence (XRF), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). According to the Chemical Index of Alteration and Chemical Index of Weathering, the celadonitic clay samples were formed by strong chemical alteration of the Kızıltepe volcanic rocks occurring in the study area. Based on XRD data, SEM-EDS data and chemical and thermal analysis results, the primary minerals present were celadonite-Al, montmorillonite and nontronite in the clay samples formed by the weathering of basaltic rocks. The clay samples were used in thermal and physical tests. Firing properties, including water absorption, dry shrinkage, firing shrinkage, total shrinkage and glaze adhesion, were determined. The white clay specimens are suitable for more decorative and less load-bearing applications, having high porosity and low strength. The green clay samples, however, are ideal for technical and industrial ceramics, having an extremely compact structure and high strength. The properties of these two clays are beneficial for application in different areas in terms of their mechanical and ceramic performance. Additionally, the representative green celadonitic clay samples were used in recipes for opaque, transparent and matte glazes, creating artistic glaze effects for pigments. Hence, the green clay samples could be used as a ceramic pigment.

Iron mining waste is produced from the iron ore mining operations of El Ouenza Mine (north-east Algeria), and it is not currently recycled to preserve the environment. The current study aims at developing sustainable clay bricks by mixing clay with different proportions of iron mining waste (ranging from 10 to 50 wt.%) and fired at 850°C and 950°C. Addition of 30 wt.% Iron mining waste had a positive effect on the physical and mechanical properties of the fired clay bricks. Linear shrinkage, water absorption and porosity were reduced, while compressive and flexural strengths were increased. Furthermore, up to 30 wt.% of iron mining waste addition to the mixtures improved compressive and flexural strengths to 59.17 and 10.06 MPa, respectively, when the bricks were fired at 950°C. According to their thermal conductivity, the bricks with 10–50 wt.% iron mining waste are considered as thermal insulators, with thermal conductivity values ranging from 0.45 to 0.56 W m–1 K–1. Adding 30 wt.% of iron mining waste can lead to the production of eco-friendly bricks with high mechanical and thermal properties, generating economic and environmental benefits.

The dissolution kinetics occurring on clay minerals are influenced by various factors, including pH, temperature and mineral lattice structure. However, the influence of the surfactant is rarely studied. In the present work, cationic surfactants were investigated in terms of the dissolution of clay minerals in acidic environments. Kaolinite was selected as the representative clay mineral. The cationic surfactant inhibited the dissolution of clay minerals because it limited the attack of H+ on the kaolinite surface and then inhibited the dissolution of kaolinite by modifying the hydrophilicity of the kaolinite surface towards hydrophobicity. The inhibition ability of the surfactant might be related to its molecular structure and the type of acid used in dissolution experiments.

This article addresses the subject of treating clayey soils to reduce the swelling in this type of soil. The study used a calcium-rich solution and examined the influence of this solution on the <2 μm clay fraction, on the non-clay fraction and on clay soil swelling. The dissolution of clay-fraction minerals during this treatment was also examined. A mineralogical and free-swelling analysis was carried out on three natural clay soils from three different locations in Algeria. The solution rich in Ca ions had a significant influence on clay mineralogy, as all the clay minerals nearly disappeared and only traces of smectite, illite, chlorite and kaolinite remained. The almost complete disappearance of minerals after contact with the Ca solution may be linked to the high pH of the porewater, because an increase in pH accelerates the alteration of these minerals. The pH of the solution induced significant modifications in the samples, revealing the high reactivity of the minerals during this treatment. Furthermore, the treatment allowed for a nearly total reduction of the sensitivity of these soils to water (i.e. swelling).