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This investigation examines the effect of clamshell ash (CSA) and lime additives on the physico-mechanical characteristics of kaolinite clay soil stabilized at the optimum silica fume content. Laboratory tests were performed to assess plasticity, shrink-swell characteristics, compaction characteristics, unconfined compressive strength (UCS), shear strength characteristics, mineralogical and morphological microstructure characteristics of stabilized soil specimens. The kaolinite clay soil was stabilized at its optimum silica fume content (6%) to produce the highest strength and was altered with three non-identical proportions of clamshell ash and lime (3%-9%). Cylindrical soil specimens, 76 mm in height and 38 mm in diameter, were moulded and treated for curing periods of 1, 7, 14, and 30 days to examine the strength of the altered soil. The findings revealed that, adding clamshell ash and lime significantly alters the plasticity, shrink-swell, maximum dry unit weights, and optimum moisture contents of the silica fume-stabilized soil. In terms of strength, the beneficial effects of CSA and lime additives were found to be more significant with more extended curing periods. Incremental increases in curing periods resulted in further enhancements in UCS, cohesion, and internal friction angle, indicating continued strength development over time. Microstructural analysis using field emission scanning electron microscopy and X-ray diffraction provided insights into the interparticle bonding mechanisms and microstructural changes induced by the addition of CSA and lime. The emergence of cementitious phases and pozzolanic responses between soil particles and stabilizers contributed to the densification and strengthening of the stabilized soil matrix. The findings of this study provide valuable insights into the potential of clamshell ash and lime additives to enhance the engineering properties of kaolinite clay soil stabilized with silica fume. These results have implications for sustainable soil stabilization practices, offering a promising approach to improve the performance of soils for various engineering applications, including construction and geotechnical projects.

Clay minerals are actively used to obtain a bioactive composite. Kaolinite, as a representative of clay minerals, possesses unique properties essential for the creation of biocomposite materials. This mineral, characterized by its distinctive layered structure, is chemically inert, highly stable, thermally resistant, eco-friendly, biocompatible, and non-toxic. Kaolinite, which plays the role of a carrier in this work, has such properties and can be the basis for biologically active composites. Antibacterial composites, namely, kaolinite/chlorhexidine and kaolinite/triclosan, were synthesized by impregnation of calcined and non-calcined samples of natural kaolinite with the antibacterial agents chlorhexidine and triclosan. The structure, morphology, elemental composition, and mineralogical characteristics of the natural and synthesized kaolinite/chlorhexidine (KAO/CHX) and kaolinite/triclosan (KAO/TCS) composites were investigated by methods of analysis such as X-ray diffraction, FTIR (Fourier-transform infrared) spectroscopy, and scanning electron microscopy. The calcined kaolinite/chlorhexidine composite at 500 °C (KAO500°C/CHX) exhibited a higher content of antiseptics compared to the non-calcined kaolinite composite. The antibacterial activities of the kaolinite/chlorhexidine and kaolinite/triclosan composites were investigated against Gram-positive Staphylococcus epidermidis and Gram-negative Klebsiella pneumoniae and Escherichia coli strains by the well diffusion method and dilution method. The highest zone of inhibition was observed against Staphylococcus epidermidis (30.00 ± 0.00 mm and 30.67 ± 0.58 mm) by applying KAO/TCS and KAO500°C/TCS via the well diffusion method. The minimum bactericidal concentration of the kaolinite/TCS composite was 15.63 μg/mL for Staphylococcus epidermidis and Klebsiella pneumoniae.

Algerian kaolinite, sourced from Djebel Debbagh nuance 3 (DD3), was used as a low-cost adsorbent to remove methylene blue (MB) dye from water. Its adsorption capacity was enhanced through sulfuric acid treatment (treated-DD3). In response to the urgent demand for clean water, various technologies have been developed to address dye removal from wastewater. This study, specifically delving into the treatment of textile wastewater, examined the efficacy of treated-DD3 through adsorption processes. The acid treatment increased the surface area and pore volume of DD3. X-ray diffraction showed crystalline phases in both, with treated-DD3 having higher crystallinity. Fourier-transform infrared spectroscopy found no significant differences post-acid treatment. Scanning electron microscopy revealed DD3 had large, stacked particles with low surface area, while treated-DD3 had increased porosity and a smoother surface. Various parameters affecting MB adsorption were studied. The Langmuir and Freundlich models were used for isotherm parameters. Treated-DD3 exhibited a higher MB adsorption capacity (64.58 mg/g according to the Langmuir model) than DD3 (44.48 mg/g). Thermodynamic analysis indicated spontaneous and endothermic MB adsorption onto both DD3-BM and treated-DD3-BM systems under different pH conditions. Treated-DD3 effectively reduced chemical oxygen demand (from 304.056 mg/L to 34.44 mg/L) and biological oxygen demand (from 80 mg/L to 20 mg/L) in real textile wastewater. The adsorbent exhibited rapid removal and decolorization, surpassing 93% within the first 7 min of the experiment. The Gaussian process regression and particle swarm optimization (GPR–PSO) predicted MB adsorption capacity effectively (R = 0.9989, R2 = 0.9978, adj-R2 = 0.9978, RMSE = 1.1390, and MAE = 0.3926).

The kaolinite content is principally responsible for the durability performance of Limestone Calcined Clay Cement (LC3), which calls into question its global applicability. The clay supply has a significant impact on the LC3 system’s reduced carbon footprint advantage. The influence of kaolinite concentration from two separate clays (collected in East South-East Europe) on the durability performance of concrete was investigated in this study. The low-kaolinitic clay had 18% kaolinite, while the medium-kaolinitic clay contained around 41% kaolinite. The compressive strength, chloride intrusion, electrical conductivity, surface resistivity, and sorptivity index were measured on concrete after 28 days. Furthermore, the pore structure development of these mixtures was investigated in relation to the kaolinite content of the mixtures. The reactivity test was performed on clays to measure their reactivity levels within the cementitious system. The results show that kaolinite content has a moderate effect on compressive strength, but it has a considerable effect on other durability indices. When compared to the Portland cement mixture, the chloride migration and diffusion coefficients were reduced by 50% and 36%, respectively, in the combination with a medium kaolinite content (more than 40%). The low-kaolinitic clay, on the other hand, achieved 60% of the chloride penetration resistance of the medium-kaolinitic clay. Furthermore, low-kaolinitic clay has been demonstrated to be suitable for low-carbon concrete in moderate exposure conditions.

Global resources of heavy Rare Earth Elements (REE) are dominantly sourced from Chinese regolith-hosted ion-adsorption deposits in which the REE are inferred to be weakly adsorbed onto clay minerals. Similar deposits elsewhere might provide alternative supply for these high-tech metals, but the adsorption mechanisms remain unclear and the adsorbed state of REE to clays has never been demonstrated in situ. This study compares the mineralogy and speciation of REE in economic weathering profiles from China to prospective regoliths developed on peralkaline rocks from Madagascar. We use synchrotron X-ray absorption spectroscopy to study the distribution and local bonding environment of Y and Nd, as proxies for heavy and light REE, in the deposits. Our results show that REE are truly adsorbed as easily leachable 8- to 9-coordinated outer-sphere hydrated complexes, dominantly onto kaolinite. Hence, at the atomic level, the Malagasy clays are genuine mineralogical analogues to those currently exploited in China. Global resources of heavy Rare Earth Elements (REE) are dominantly sourced from Chinese regolith-hosted ion-adsorption deposits, yet the adsorption mechanisms remain unclear. Here, the authors find that heavy REE are adsorbed as easily leachable 8-coordinated outer-sphere hydrated complexes, dominantly onto kaolinite, in clays from both China and Madagascar.

Understanding how surfactants interact with clay minerals is essential for controlling organoclay properties and improving hydrocarbon adsorption performance. However, distinguishing between surfactant adsorption on external surfaces and within interlayer galleries remains challenging using conventional techniques. In this study, we introduce a combined Washburn–immersion methodology that enables both quantification of total surfactant adsorption and localization of adsorbed species. Bentonite and kaolinite were modified using three commercial detergent formulations at concentrations below their experimentally determined critical micelle concentrations (CMC). The resulting changes in wettability, interlayer accessibility, and hydrocarbon uptake were systematically examined. For the first time, this study provides a quantitative framework to distinguish between external-surface adsorption and true interlayer incorporation of surfactants in clay minerals and directly links adsorption location to hydrocarbon uptake behavior. Bentonite exhibited significantly higher surfactant uptake (2.83–3.10 mg·g −1 ) accompanied by substantial interlayer incorporation, resulting in enhanced organophilicity and a 13–33% increase in diesel and kerosene adsorption. In contrast, kaolinite showed lower surfactant uptake (2.46–2.70 mg·g −1 ) dominated by surface and edge adsorption, leading to a 10–30% reduction in persistent diesel uptake, while kerosene adsorption remained essentially unchanged. Interlayer density analysis further confirmed that surfactant intercalation promotes denser hydrocarbon packing in bentonite but has negligible influence on kaolinite. This work introduces a robust and scalable diagnostic approach for distinguishing surface and interlayer adsorption in surfactant–clay systems, offering a practical framework for screening and optimizing surfactant-modified clays intended for hydrocarbon sorption under controlled conditions.

Death from acute hemorrhage is a major problem in military conflicts, traffic accidents, and surgical procedures, et al. Achieving rapid effective hemostasis for pre-hospital care is essential to save lives in massive bleeding. An ideal hemostasis material should have those features such as safe, efficient, convenient, economical, which remains challenging and most of them cannot be achieved at the same time. In this work, we report a rapid effective nanoclay-based hemostatic membranes with nanoclay particles incorporate into polyvinylpyrrolidone (PVP) electrospun fibers. The nanoclay electrospun membrane (NEM) with 60 wt% kaolinite (KEM1.5) shows better and faster hemostatic performance in vitro and in vivo with good biocompatibility compared with most other NEMs and clay-based hemostats, benefiting from its enriched hemostatic functional sites, robust fluffy framework, and hydrophilic surface. The robust hemostatic bandages based on nanoclay electrospun membrane is an effective candidate hemostat in practical application. Rapid, easy and effective haemostasis is needed to reduce the loss of life from traumatic haemorrhage. Here, the authors report on the creation of polymer-nanoclay electrospun membranes and demonstrate haemostatic effects showing superior effects to other clay based haemostats.

The development of novel materials and approaches for effective energy consumption and the employment of renewable energy sources is one of the current trends in modern material science. With this respect, the number of researches is focused on the effective harvesting and storage of solar energy for various applications. Phase change materials (PCMs) are known to be able to store thermal energy of the sunlight due to adsorption and release of latent heat through reversible phase transitions. Therefore, PCMs are promising as functional additives to construction materials and paints for advanced thermoregulation in building and industry. However, bare PCMs have limited practical applications. Organic PCMs like paraffins suffer from material leakage when undergoing in a liquid state while inorganic ones like salt hydrates lack long-term stability after multiple phase transitions. To avoid this, the loading of PCMs in porous matrices are intensively studied along with the thermal properties of the resulted composites. The loading of PCMs in microcontainers of natural porous or layered clay materials appears as a simple and cost-effective method of encapsulation significantly improving the shape and cyclic stability of PCMs. Additionally, the inclusion of functional clay containers into construction materials allows for improving their mechanical and flame-retardant properties. This article summarizes the recent progress in the preparation of composites based on PCM-loaded clay microcontainers along with their future perspectives as functional additives in thermo-regulating materials.

The paper studies the effect of successive heating and the addition of waste glass on the properties of a traditional porcelain mixture. The porcelain consisted of 50 wt.% kaolinitic clay, 25 wt.% feldspar, and 25 wt.% quartz, with feldspar being gradually replaced by waste glass in amounts ranging from 5 to 25 wt.%. The thermal behavior of the samples was analyzed through successive heating up to 1100°C, focusing on the physical and structural changes in kaolinite, including water loss, dehydroxylation, and sintering effects.

The kaolinite sheets were scrolled by sonication-induced chemical delamination processes into well-developed nanotubes (KNs) which were used as substrates for microwave-based ZnO nanoparticles (ZnO/KNs). The biological activities of synthetic ZnO/KNs structures, in terms of the antioxidant and antidiabetic properties, were assessed in comparative studies with the separated phases of the synthetic ZnO and KNs as well as the commercially used ZnO. The KNs substrate resulted in a notable enhancement in the antioxidant and antidiabetic properties of ZnO, which was assigned positive influence on the surface area, interactive interfaces, charge separation, and agglomeration properties of ZnO in addition to the detectable bioactive properties of the KNs structure. The ZnO/KNs structure achieved remarkable scavenging efficiencies for 1, 1-diphenyl-2-picrylhydrazil (DPPH) (89.8 ± 1.57%), nitric oxide (90.6 ± 1.63%), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) (86.8 ± 1.28%), and superoxide (43.9 ± 1.72%) radicals. Additionally, it shows high inhibition effects on porcine α-amylase (84.3 ± 1.92%), crude α-amylase (70.6 ± 1.37%), pancreatic α-Glucosidase (94.7 ± 1.54%), crude α-Glucosidase (95.4 ± 1.64%), and amyloglucosidase (95.3 ± 1.32%) enzymes. This antidiabetic activity is significantly higher than the activity of miglitol and close to or slightly higher than acarbose, which leads us to recommend the use of ZnO/KNs when considering the cost and side effects of the commercially used drugs.