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Building on traditional emulsion polymerization research, which continues to yield results up to the present day, techniques have emerged to produce hybrid materials. One such technique is Pickering emulsion polymerization, with numerous industrial applications. Despite a growing interest in Pickering emulsion polymerization, the intrinsic mechanisms involved have been based mainly on the findings of classical emulsion polymerization. In this work, by relying on a minimum of assumptions and using a simple model and experimental data on conversion and particle size, we obtain information about the prevailing mechanisms. More specifically, we present four main findings based on data reported previously in the literature. First, in contrast to the three rate-of-reaction intervals reported in classical emulsion polymerization, the integro-differential method yielded only two rate-of-reaction intervals against conversion. Second, a master curve is constructed by plotting the reaction rate against overall conversion, showing a maximum of approximately 55% conversion. Third, despite having a semicontinuous process, monomer concentration inside the particles is not constant. Finally, particle density is a strong function of the Pickering agent concentration, where two fitting parameters (nucleation and coagulation) allowed an accurate description for the particle number time evolution. Both parameters showed a power-law dependence with clay concentration. [ABSTRACT FROM AUTHOR]

2024 aluminum alloy has high strength, processing performance, and good damage tolerance performance, but it is prone to intergranular corrosion and pitting. Therefore, the development of corrosion protective coatings is essential for the aluminum alloy. In this paper, cerium ion (Ce3+) was doped into chitosan‐modified montmorillonite (Ce‐CS‐MMT) by ion exchange method, and the corrosion protective performance of Ce‐CS‐MMT epoxy coating (Ce‐CS‐MMT/EP) was investigated. The electrochemical analysis of aluminum alloy in cerium‐containing solution showed the corrosion inhibition efficiency reached 95.52%. The result indicates the corrosion inhibition effect of cerium‐containing solution was better than pure NaCl solution and MMT solution. The corrosion study of the coating illustrates that the protection rate of Ce‐CS‐MMT/EP reached 95.82%, which was higher than that 91.83% of Ce‐MMT/EP. The result indicates the resistance of charge transfer was greater and the better shielding effect for electrolyte corrosion ions than MMT and Ce‐MMT epoxy coatings, and the corrosion protective performance was excellent. [ABSTRACT FROM AUTHOR]

This study focuses on utilizing montmorillonite (MMT) to induce a multi-micro/nanolayer morphology in PA6/ABS blend polymers by mitigating phase retraction and coalescence. Both untreated and modified MMT were incorporated at weight contents ranging from 1 to 5 wt% to manipulate morphology through selective localization at the interface. The nanocomposites' morphology was analyzed, and the cooperative effects were correlated with their structural, thermal, rheological, and mechanical characteristics. Structural analysis revealed that intercalation resulted in the appearance of novel bands, particularly in CTAB-modified MMT, which adopted a tilted monolayer arrangement. SEM results demonstrated excellent distribution and dispersion of exfoliated modified MMT, effectively suppressing coalescence and promoting a finer multilayer morphology. Compared to nanocomposites based on unmodified MMT, the ones based on CTAB-modified MMT exhibited superior thermal stability. Furthermore, the stiffness of the blend matrix increased with clay content, and the nanocomposites stabilized with modified MMT showed enhanced strain-to-failure properties. [ABSTRACT FROM AUTHOR]

The presence of heavy metals in aqueous media threatens environmental safety and human health, so it is necessary to effectively remove them from wastewater. Through a simple preparation method, lignin (LS) and montmorillonite (MMT) were successfully prepared into efficient biosorbents. The prepared hydrogel not only has water absorption and pH-responsive swelling properties, but also has good removal effect on heavy metals. The maximum adsorption capacity of Cd (II) ions was 587.14 mg / g. The maximum adsorption capacity of Zn (II) ions was 297.13 mg / g.The results of principal component analysis show that the adsorption process of heavy metals is in good agreement with different kinetic and isotherm models. The adsorption mechanism is proposed, which is related to the chemical properties between adsorbents. This study provides a promising and sustainable lignin-based composite hydrogel. [ABSTRACT FROM AUTHOR]

Although biopolymers have been widely utilized as triboelectric materials for the construction of self-powered sensing systems, the annihilation of triboelectric charges at high temperatures restricts the output signals and sensitivity of the assembled sensors. Herein, a novel chitosan/montmorillonite/lignin (CML) composite film was designed and employed as a tribopositive layer in the assembly of a self-powered sensing system for use under hot conditions (25–70°C). The dense contact surface resulting from the strong intermolecular interaction between biopolymers and nanofillers restrained the volatilization of induced electrons. The optimized CML-TENG delivered the highest open-circuit voltage (Voc) of 262 V and maximum instantaneous output power of 429 mW/m2. Pristine CH-TENG retained only 39% of its initial Voc at 70°C, whereas the optimized CM5L3-TENG retained 66% of its initial Voc. Our work provides a new strategy for suppressing the annihilation of triboelectric charges at high temperatures, thus boosting the development of self-powered sensing devices for application under hot conditions. [ABSTRACT FROM AUTHOR]

TiO2 used for photocatalytic water purification is most active in the form of nanoparticles (NP), but their use is fraught with difficulties in separation from solution or/and a tendency to agglomerate. The novel materials designed in this work circumvent these problems by immobilizing TiO2 NPs on the surface of exfoliated clay minerals. A series of TiO2/clay mineral composites were obtained using five different clay components: the Na-, CTA-, or H-form of montmorillonite (Mt) and Na- or CTA-form of laponite (Lap). The TiO2 component was prepared using the inverse microemulsion method. The composites were characterized with X-ray diffraction, scanning/transmission electron microscopy/energy dispersive X-ray spectroscopy, FTIR spectroscopy, thermal analysis, and N2 adsorption–desorption isotherms. It was shown that upon composite synthesis, the Mt interlayer became filled by a mixture of CTA+ and hydronium ions, regardless of the nature of the parent clay, while the structure of Lap underwent partial destruction. The composites displayed high specific surface area and uniform mesoporosity determined by the size of the TiO2 nanoparticles. The best textural parameters were shown by composites containing clay components whose structure was partially destroyed; for instance, Ti/CTA-Lap had a specific surface area of 420 m2g−1 and a pore volume of 0.653 cm3g−1. The materials were tested in the photodegradation of methyl orange and humic acid upon UV irradiation. The photocatalytic activity could be correlated with the development of textural properties. In both reactions, the performance of the most photoactive composites surpassed that of the reference commercial P25 titania. [ABSTRACT FROM AUTHOR]

In order to mitigate the release of toxic phosphine from aluminum hypophosphite in twin-screw processing, montmorillonite–melamine cyanurate was prepared by three methods: (1) mechanical intercalation, (2) water intercalation and (3) in situ intercalation. The sheet spacing of montmorillonite was increased from 1.140 nm to 1.141 nm, 1.208 nm and 1.217 nm for these three methods, respectively, and scanning electron microscope (SEM) and transmission electron microscopy (TEM) proved that melamine cyanurate was successfully inserted into the montmorillonite sheets. The montmorillonite–melamine cyanurate from in situ intercalation can best inhibit the release of PH3 from aluminum hypophosphite, and the peaks of phosphine, mean values of phosphine and integral of phosphine were reduced by 81.9%, 72.1% and 72.2%, respectively. The mode of action of montmorillonite–melamine cyanuric inhibition of the emission of phosphine from aluminum hypophosphite can be attributed to the physical absorption of montmorillonite and the chemical bonding of melamine cyanurate. In addition, in situ intercalation can slightly improve flame retardancy, attributed to incomplete exfoliation of montmorillonite sheets. [ABSTRACT FROM AUTHOR]

Compared with conventional lithium‐ion battery systems, anion‐intercalation in graphite cathodes opens avenues for the development of batteries with groundbreaking power density. This study explores the enhancement of dual‐ion batteries (DIBs) by gel polymer electrolyte (GPE) enhanced with surface‐charged nanoclays, focusing on overcoming traditional challenges such as electrolyte decomposition, anion‐solvent co‐intercalation, and interfacial instability at the graphite cathode. Three nanoclays including montmorillonite, kaolinite, and halloysite are compared by incorporating them into GPE and evaluating their effect on the electrochemical properties, ion conduction, and mechanical integrity of DIBs. Particular attention is paid to the halloysite because of its differential internal and external surface charges, which generate charge separation, facilitate optimal lithium‐ion transport, and mitigate undesirable anion‐solvent interactions. These results indicate that halloysite‐incorporated GPE (HS‐G) significantly improves DIB performance, as demonstrated by extended cycle life, robust capacity retention at fast charge/discharge rates of 20 C, and operational stability over a wide temperature range (0–60 °C). These improvements are attributed to the unique structural advantages of HS‐G, including effective charge separation, enhanced anion diffusion, and reduced solvent co‐intercalation, which provide an environmentally friendly and cost‐effective approach to advanced DIB applications. [ABSTRACT FROM AUTHOR]

The tolerance requirement of lithium metal batteries in harsh environments presents great challenges to electrode materials and electrolytes because temperature plays a significant effect in electrochemical processes. In this study, a new artificial layer on a copper current collector that boosts the de‐solvation kinetics and provides electrostatic shielding effects is presented to enhance the electrochemical performance of lithium metal batteries. This new artificial layer is constructed with poly(diallyl dimethyl ammonium chloride) (PDDA) and exfoliated montmorillonite (MMT) nanosheets, which combine the advantages of both inorganic clay and organic polymer. Within this protective hybrid layer, the PDDA cations increase the interlayer spacing of MMT, broadening the diffusion pathways of Li+ and accelerating their fast diffusion. Moreover, the PDDA‐MMT protective layer facilitates Li+ de‐solvation at the interface of the Li anode and electrolyte, enabling the rapid and reversible plating/stripping of lithium metal. As a result, the as‐prepared PDDA‐MMT@Cu anode exhibits excellent stability, and good rate performance is achieved in a commercial electrolyte in the temperature range of −20–60 °C. By combining enhanced diffusion kinetics and electrostatic shielding as an artificial protective layer, this clay‐polymer composite provides a synergistic interaction and offers new inspiration for the development of lithium metal batteries. [ABSTRACT FROM AUTHOR]

In this study, a cationic polyelectrolyte (Poly dimethyl diallyl ammonium chloride, PDADMAC) was introduced as a filter aid to enhance the dewatering effect of montmorillonite (MT)-containing coal slime, and compared with cationic polyacrylamide (CPAM). The dewatering performance of PDADMAC and CPAM was evaluated based on vacuum filtration experiments. The modification mechanism of PDADMAC on Mt particle surface was revealed by filter cake pore distribution, zeta potential, contact angle and Atomic Force Microscopy (AFM). The adsorption difference between PDADMAC and CPAM on Mt surface was studied by Density Functional Theory (DFT). In addition, DLVO theory further explains the mechanism of PDADMAC enhancing dewatering from the perspective of interaction force. The optimal dosage of PDADMAC was 125 g/t, and the filter cake moisture content was reduced by 3%. Compared to CPAM, PDADMAC achieves efficient dewatering at a lower dosage. PDADMAC has a more prominent ability to neutralize charge, and its effect on interparticle interactions was a potential mechanism to promote dehydration. [ABSTRACT FROM AUTHOR]

The quantity of silane chemically bonded to the organoclay's surface significantly influences its dispersion within the polymer matrix, as well as the interfacial interaction. This research presents a groundbreaking method for enhancing the surface properties of montmorillonite (Mt) through the use of γ‐(methacryloxy) propyl trimethoxy silane (KH570) coupled with acid treatment, leading to increased grafting efficiency. Confirmed by FT‐IR, TGA, and XRD, the process effectively bonds organo‐silanes to Mt and achieves a high grafting level of 1.59 mequiv/g. Utilizing a latex compounding method, Mt/rubber nanocomposites are synthesized with thoroughly modified clay for peak performance. Dispersion and interfacial properties are evaluated through XRD, TEM, AFM, and DMTA. The findings reveal that the well‐modified Mt is an exceptional filler, ensuring a high level of dispersion and robust interaction with the rubber matrix. This synergy translates to a marked improvement in the mechanical properties of the composite, with notable enhancements observed in both tensile strength and elongation at break of 9.7 MPa and 1141%, respectively. This innovative approach to the graft modification of clays presents a potent method, offering the potential for the industrial‐scale manufacture of high‐performance clay‐based composites. Highlights: A processing method for preparing high grafting clay with a silane coupling agent.Functionalized clay presents better nano‐dispersion in the polymeric matrix.Strong covalent interfacial interaction is constructed between clay and rubber.Tensile Strength and elongation at break of the composites are obliviously improved. [ABSTRACT FROM AUTHOR]

Microemulsions originating from food industries, textiles, paint industries, kitchen wastes, and oil spills on roads ultimately form a complex cocktail of emulsified water sources that are difficult to separate. Traditional methods often fail to provide stable and efficient separation of these microemulsions at the tertiary stage, highlighting the need for advanced membrane technologies. This study explores the incorporation of nickel oxide and montmorillonite (NiO-MMT) nanoparticles into poly-(vinylidene fluoride) (PVDF) membranes to enhance the separation of microemulsified oil from water. By integrating 2% NiO-MMT, the membrane surface becomes significantly smoother compared to pristine PVDF membranes, thereby enhancing its antifouling properties. The addition of NiO-MMT significantly improves the hydrophilicity of the membrane matrix, resulting in a pure water permeance of up to 3781 ± 3% L·m–2·h–1·bar–1. Experimental results indicate that NiO-MMT-incorporated PVDF membranes exhibit a >5.3 times increase in motor oil–water separation efficiency and a 1.4 times increase in the separation efficiency of both palm oil and mustard oil from water compared to pristine membranes. The hydrophilic nature and high surface energy of the composite membrane effectively separates stable microemulsified oil from water, achieving an 80% permeance recovery after six filtration cycles. This contributes to environmental sustainability and technological advancements in various industrial applications. [ABSTRACT FROM AUTHOR]

The efficient dewatering of montmorillonite (Mt)-containing coal slime is still an urgent problem to be solved in coal preparation plant. In this study, the dewatering effect of poly(o-phenylenediamine)/Poly dimethyl diallyl ammonium chloride (POPD/PDADMAC) combined filter aid on Mt-containing coal slime was studied. The dewatering performance of combined filter aid was investigated by vacuum filtration test. The action mechanism of combined filter aid was revealed by contact angle, zeta potential, cake pore and atomic force microscope (AFM). The co-adsorption principle of the combined filter aid was elucidated based on density functional theory (DFT) and molecular dynamics simulation (MD). Compared to PDADMAC, the combined filter aid has better performance for dewatering of Mt-containing coal slime, and has the advantage of low reagent dosage. The combined filter aid can greatly reduce the Mt potential, increase the Mt contact angle, and increase the porosity of the filter cake. There was a co-adsorption effect between the combined filter aid. Specifically, there were ion–dipole interaction, cation–π interaction and Cl ions bridged electrostatic interaction between POPD and PDADMAC. This study has developed a novel combined filter aid, which provides theoretical and technical support for the high-efficiency pressure filtration dewatering of Mt-containing coal slime in coal preparation plants. [ABSTRACT FROM AUTHOR]

The extraction of natural red dye (PR) from the flower Papaver rhoeas (common poppy) and its adsorption on montmorillonite clay (PR@MM) was reported. The powder PR@MM was used for the development and visualization of LFPs taken on common household, nonporous, and colored surfaces in daylight using powder dusting method without any pre‐ or posttreatment and equipment. The information of level 1 (ridge classification) and level 2 (minutiae details) from the fingerprint can be obtained using PR@MM powder. [ABSTRACT FROM AUTHOR]

The proposed paper describes a simple and environmentally friendly method for the synthesis of three-component polymer–inorganic composites, which includes the modification of zinc oxide or montmorillonite (MMT) with chitosan (CS), followed by the immobilization of palladium on the resulting two-component composites. The structures and properties of the obtained composites were characterized by physicochemical methods (IRS, TEM, XPS, SEM, EDX, XRD, BET). Pd–CS species covered the surface of inorganic materials through two different mechanisms. The interaction of chitosan polyelectrolyte with zinc oxide led to the deprotonation of its amino groups and deposition on the surface of ZnO. The immobilization of Pd on CS/ZnO occurred by the hydrolysis of [PdCl4]2−, followed by forming PdO particles by interacting with amino groups of chitosan. In the case of CS/MMT, protonated amino groups of CS interacted with negative sites of MMT, forming a positively charged CS/MMT composite. Furthermore, [PdCl4]2− interacted with the –NH3+ sites of CS/MMT through electrostatic force. According to TEM studies of 1%Pd–CS/ZnO, the presence of Pd nanoclusters composed of smaller Pd nanoparticles of 3–4 nm in size were observed on different sites of CS/ZnO. For 1%Pd–CS/MMT, Pd nanoparticles with sizes of 2 nm were evenly distributed on the support surface. The prepared three-component CS–inorganic composites were tested through the hydrogenation of 2-propen-1-ol and acetylene compounds (phenylacetylene, 2-hexyn-1-ol) under mild conditions (T—40 °C, PH2—1 atm). It was shown that the efficiency of 1%Pd–CS/MMT is higher than that of 1%Pd–CS/ZnO, which can be explained by the formation of smaller Pd particles that are evenly distributed on the support surface. The mechanism of 2-hexyn-1-ol hydrogenation over an optimal 1%Pd–CS/MMT catalyst was proposed. [ABSTRACT FROM AUTHOR]

Organic semiconductors are used in organic opto‐electronic devices because of their various advantages. However, they are vulnerable to moisture and oxygen. Thus, flexible and transparent encapsulations with barrier properties against moisture and oxygen need to be developed to fabricate bendable and foldable organic semiconductor devices. In this study, a simple and highly productive self‐assembly process is developed from montmorillonites by using maximized Marangoni forces and a co‐solvent in an aqueous water and a non‐aqueous N‐methyl‐2‐pyrrolidone medium for the fabrication of a flexible and transparent encapsulation film. Water vapor transmission rate (WVTR) and optical transmittance of montmorillonite‐based flexible and transparent encapsulation films are modulated using different precursor solution concentrations and numbers of stacked montmorillonite layers. Long‐term stability of transparent polymer solar cells with self‐assembled flexible and transparent encapsulation films (WVTR of 6.66 × 10−3 g m−2 day−1 and optical transmittance of 90.5% at 550 nm) is enhanced, and performance of flexible polymer light‐emitting diodes with flexible encapsulation films is maintained after 1000 bending cycles, even at a bending radius of 2 mm. Mechanical properties of prepared encapsulation films are analyzed by conducting tensile tests and finite element analysis simulations, demonstrating that an integrated analysis includes both devices and encapsulation films. [ABSTRACT FROM AUTHOR]

The effects of micro-sized montmorillonite clay (MMT) on Portland cement concrete were examined in this study, focusing on regular and calcined MMT as partial cement replacements. Key properties assessed include consistency, setting time, flexural strength, and compressive strength at 7 and 28 days. Regular MMT initially acts as an inert filler, potentially reducing compressive strength, while calcined MMT improves compatibility and strength. Both types extend the setting time, with regular MMT causing more delay. The study highlights that the regular MMT increases water demand and setting time, whereas calcined MMT enhances strength and mitigates these issues. The results emphasize the importance of carefully choosing MMT type and dosage. [ABSTRACT FROM AUTHOR]

Inflammatory bowel diseases (IBD) are often associated with dysregulated gut microbiota and excessive inflammatory microenvironment. Probiotic therapy combined with inflammation management is a promising approach to alleviate IBD, but the efficacy is hindered by the inferior colonization of probiotics in mucus-depleted inflammatory bowel segments. Here, we present modified montmorillonite armed probiotic Escherichia coli Nissle 1917 (MMT-Fe@EcN) with enhanced intestinal colonization and hydrogen sulfide (H 2 S) scavenging for synergistic alleviation of IBD. The montmorillonite layer that can protect EcN against environmental assaults in oral delivery and improve on-site colonization of EcN in the mucus-depleted intestinal segment due to its strong adhesive capability and electronegativity, with a 22.6-fold increase in colonization efficiency compared to EcN. Meanwhile, MMT-Fe@EcN can manage inflammation by scavenging H 2 S, which allows for enhancing probiotic viability and colonization for restoring the gut microbiota. As a result, MMT-Fe@EcN exhibits extraordinary therapeutic effects in the dextran sulfate sodium-induced mouse colitis models, including alleviating intestinal inflammation and restoring disrupted intestinal barrier function, and gut microbiota. These findings provide a promising strategy for clinical IBD treatment and potentially other mucus-depletion-related diseases. We present modified montmorillonite armed probiotic Escherichia coli Nissle 1917 (MMT-Fe@EcN) with enhanced intestinal colonization and hydrogen sulfide (H 2 S) scavenging for synergistic alleviation of IBD. [Display omitted] • Montmorillonite coating enhanced on-site mucus-depleted intestinal colonization of probiotics. • Fe3+-modified Montmorillonite can scavenge elevated H 2 S and alleviate inflammatory factors, which allows for enhancing probiotic viability and colonization for restoring the gut microbiota. • Improved probiotic colonization and intestinal microenvironment regulation exhibited synergistic alleviation of inflammatory bowel disease. [ABSTRACT FROM AUTHOR]

Montmorillonite (MMT) is an aluminosilicate clay with specific properties, such as improving growth performance and enhancing immunity. The effects of MMT supplements on performance, survival rate, body composition, haemolymph parameters, relative gene expressions, and antioxidant response of whiteleg shrimp (Litopenaeus vannamei) were investigated. Five diets with MMT supplementation were formulated at 0 (Control), 10 (MMT1), 20 (MMT2), 30 (MMT3) and 40 (MMT4) g/kg representing five treatments in replicates (15 tanks). A quadratic relation existed between the growth, feed conversion ratio, lysozyme and penaeidin3a and the MMT levels (further, MMT1 and MMT2 had significantly higher levels than other groups). Phenoloxidase, alkaline phosphatase and the expression of heat shock protein (HSP70), metallothionein and glutathione had linear relations so that MMT4 had a higher value than others (P < 0.05). Weight gain also had positive correlations with feed efficiency (correlation coefficient R: 0.76), HSP70 (R: 0.55), lysozyme (R: 0.72) and penaeidin3a (R: 0.60), while it had negative relations with daily feed intake, triglycerides and malondialdehyde. Malondialdehyde also had negative correlations with the level of MMT (R: − 0.69), weight gain (R: − 0.54), phenoloxidase (R: − 0.61), HSP70 (R: − 0.65), metallothionein (R: − 0.57) and catalase (R: 0.54) and also negative, but not significant, correlations with other measured parameters. In general, the findings of this study showed that the inclusion of MMT supplements in the diet improves the growth, antioxidant system and expression of genes related to whiteleg shrimp immunity and avoids lipid peroxidation. Most of the measured parameters suggest supplementing 20 g/kg MMT in diets of whiteleg shrimp, which is economically beneficial through improved growth and FCR. [ABSTRACT FROM AUTHOR]

[Display omitted] Heat buildup from factors like mechanical, electrical, or thermal stress is the main safety issue in lithium metal batteries (LMBs). Even without such stressors, however, LMBs may remain fire-prone because of the development of unstable electrode–electrolyte interphase on charge–discharge, potentially leading to internal short circuits. In this study, a stable cathode-electrolyte interphase inducer (SCEI-I) is proposed to tackle both the cycling stability issue and safety concerns. SCEI-I is synthesized by incorporating montmorillonite, a clay mineral, and methylphosphonic acid dimethyl ester, a flame-retardant material, onto a porous polyethylene film. On cycling, SCEI-I can induce a thin (<8 nm), uniform and robust cathode-electrolyte interphase layer, contributing to a steady and high Coulombic efficiency of 99.6%–99.8% with decreased impedance. SCE-I improves electrochemical performance by reducing the capacity degradation from ∼21.9% to ∼8.9% after 100 cycles. SCE-I also demonstrates strong thermal stability as the endothermic energy of SCEI-I is only –32.4 J/g (24 °C–280 °C), which is less than one-third of that of polypropylene separator (–118.9 J/g). Furthermore, when exposed to fire, the SCEI-I membrane instantly extinguished flames by disrupting combustion chain reaction. The present study proposes an interfacial engineering approach to improve the stability and safety of LMBs. [ABSTRACT FROM AUTHOR]

Suspended particulate matter (SPM) is an important component of natural water bodies and can significantly influence the photolytic behavior of water pollutants. A comprehensive understanding of the photochemical behavior of water pollutants in natural waters requires consideration of the presence of SPM. In this study, montmorillonite–humic acid (MMT-HA) composite particles were synthesized to simulate SPM in natural waters and their effects on the photolysis of tetracycline (TC) were investigated. The results demonstrated that the presence of MMT-HA composite particles in water significantly enhanced the photolysis of TC, with the photolytic kinetics following a pseudo-first-order model. Electron spin resonance spectra and free radical quenching experiments indicated that the photoactive components (MMT and humic acids) in the composite particles induced the generation of reactive oxygen species under light exposure, further contributing to the enhanced photolysis of TC. Comparative analysis of the free radical signals and adsorption experiments revealed that the accelerated photolysis of TC was also related to the interfacial interaction between the MMT in the composite particles and the TC molecules. The formation of surface complexes between TC molecules and the negatively charged sites on the MMT surface facilitated light absorption and electron transfer, thereby accelerating the photolysis of TC. Photoproduct analysis indicated that the primary degradation pathways of TC in the composite particle systems included the addition of hydroxyl radicals to the aromatic ring, as well as demethylation, deamination and dehydration in the side chains. This study shows that SPM in water bodies can affect the photochemical behavior of pollutants and should be taken into account when assessing the phototransformation of pollutants in natural waters. [ABSTRACT FROM AUTHOR]

In this study, we prepared sodium alginate (SA) and montmorillonite (MMT) composite films for application in coatings for strawberry preservation. SA and MMT were used as the matrix and glycerol was used as a plasticizer. Six types of composite films with different MMT contents were compared by analyzing their mechanical properties, permeability, and preservation effects. The results show that the mechanical properties of the 10 and 20% MMT composite films were superior, with tensile strength and fracture elongation values reaching 63.09 and 48.06 MPa and 5.75 and 6.47%, respectively. Increased MMT content caused the water vapor permeability to decrease, while the effect on oil permeability was the opposite. A comparison of the preservation effect provided by the coatings showed that, on day 12, the weight loss, malondialdehyde content, and respiratory intensity of strawberries treated with the 20% MMT coating liquid decreased by 43.3, 25.8, and 57.1%, respectively, compared with the control. The contents of titratable acid, soluble sugar, total phenols, and soluble solids decreased by 25.8, 37.7, 25.9, and 14.5%, respectively. The results provide data support for the application of these new composite films as edible coatings for fruit preservation. [ABSTRACT FROM AUTHOR]

This study investigated the physicochemical effects of kaolinite (CK) and montmorillonite (CM) calcined clays on the sulfate balance, early hydration, and artificial pore solution of limestone calcined clay cement (LC3). The effects of fineness, clay dissolution, and ion-adsorption capacity were evaluated by isothermal calorimetry, compressive strength, ICP-OES, and zeta potential within 72 h, respectively. Increasing the fineness of both calcined clays did not significantly affect the sulfate depletion kinetics or the compressive strength and the adsorption of Ca2+ ions onto the calcined clay's surface is not the main factor responsible for differences in sulfate demand. The higher dissolution of ions Al in CK provided an intensified and accelerated formation of ettringite that competes for the available sulfate. We demonstrate that the chemical effects have a significant impact on the sulfate balance of LC3, revealing the lesser impact of alternative clays like montmorillonite compared to metakaolin (MK) which can minimize the problem of accelerated sulfate depletion of LC3 mixes with MK. [ABSTRACT FROM AUTHOR]

Limestone calcined clay cement (LC3) is emerging as an alternative to Portland cement, offering economic advantages, reduced CO2 emissions, and mechanical properties on par with Portland cement. Central to the effective utilization of LC3 is understanding how the fineness of its components affects its performance. The current study investigates limestone calcined clay cement mixtures composed of kaolinite, illite, and montmorillonite calcined clays and limestone at two levels of fineness. Strengths of mortar cubes were tested at 1, 3, 7, and 28 d and statistical analysis was performed with a 95% confidence level. Additionally, LC3 pastes were analyzed using x-ray diffraction, mercury intrusion porosimetry, scanning electron microscopy, and isothermal calorimetry. The fineness of the calcined clay along with the fineness of limestone is found to be statistically significant for 28-d strength in LC3 mortars made with kaolinitic and montmorillonite calcined clays. All hydrated blends had a hemicarboaluminate phase, whose intensity was related to the fineness of the calcined clay, and the monocarboaluminate phase formation was found to be dependent on both the fineness and type of calcined clay. Porosimetry revealed that LC3 pastes with illite clay have larger threshold pore diameters than those with kaolinite clay. LC3 pastes containing kaolinite have denser microstructures due to C–S–H and hemicarboaluminate formation. Pastes produced with coarse calcined clay and coarse limestone led to a broader, weaker heat development peak and lower normalized cumulative heat. LC3 with kaolinitic clay has the highest normalized cumulative heat, while that with montmorillonite calcined clay has the lowest. [ABSTRACT FROM AUTHOR]

Aimed at the current problems of low strength and poor toughness in alginate fibers, which limits its large-scale application in the textile field, nano-montmorillonite (MMT) suspension was added into sodium alginate spinning solution during the wet spinning process with CaCl2 solution as the coagulation and the modified alginate fibers were obtained. The structure of the fibers was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and TGA. The mechanical properties and water regain rate of the fibers were tested, and the mechanism of intermolecular interaction between sodium alginate and MMT was analyzed. The results indicate that the mechanical properties of MMT-modified alginate fibers were significantly improved. The fracture strength of the modified alginate fibers was increased from 1.32 cN/dtex to 3.01 cN/dtex. The elongation at break increased from 9.11% to 16.05%. The preparation of alginate/MMT fibers provides a feasible reinforcement and toughening strategy for alginate fibers, which improves toughness while achieving an increase in fracture strength. The preparation of alginate fibers with high strength and good toughness is beneficial for expanding the application of textiles. [ABSTRACT FROM AUTHOR]

Due to their prevalence in the lithosphere and their high capability of sorbing pollutants, smectite clays play a foreground role in environmental pollution studies, waste management, and soil science. In complementarity with existing approaches at the molecular or macroscopic scales, real microstructures have been employed to investigate ionic transport by diffusion through montmorillonite and water-saturated Wyoming bentonite at intermediate scales ranging between the nanometer and the micrometer. The coupled solute transport and electrostatic phenomena investigated at the nanopore scale are upscaled using the homogenization of porous media approach. Homogenization computations rely on a hierarchical description of bentonite that acknowledges the existence of pores networks at different scales. At the scale of montmorillonite layers, digitized TEM images have been employed to simulate the diffusion of ionic solutes by considering electrostatic interactions in the vicinity of the negatively charged clay platelets' surface. Finite element microstructures are created after extraction of the contours of the layers using dedicated image processing algorithms. Local electric potential distribution, anion exclusion, and cation inclusion are displayed by ion distribution maps. The effective diffusion tensor and the transport equation obtained through volume averaging are then used to simulate diffusion at the scale of a Wyoming bentonite sample composed of clay gels of variable density, solid grains, and micropores. Qualitative comparisons were made with existing diffusion data, and a particular attention is given to the anisotropy of the diffusion tensors at both the mesoscopic and macroscopic scales. [ABSTRACT FROM AUTHOR]

A new composite separation membrane was developed by using organically modified montmorillonite (OMMT) as an additive. The effects of OMMT on the modification and properties of PVDF composite membranes were investigated. It is found that different kinds and amounts of OMMT into the casting solution can obviously change the pure water flux, separation performance and hydrophilicity of composite membrane in varying degrees. When the TA/PDA-MMT was 0.5 wt%, the pure water flux of the membrane reached the maximum, which was 584.7 L/(m2·h), about 6 times that of the original membrane. The OMMT/PVDF composite membrane had good hydrophilicity and stability in the treatment of oily wastewater. The development of novel OMMT/PVDF composite membrane will provide a new idea for solving the problem of oily wastewater treatment. [ABSTRACT FROM AUTHOR]

Ti-doped Bi2O3/montmorillonite (TBM) was prepared by chemical solution decomposition and used to conduct adsorption and degradation experiments. The materials were characterized by detection methods such as XRD, SEM, BET, XPS, UV-Vis DRS, etc. The results showed that doping Ti can inhibit the growth of Bi2O3 grains and destroy the layered structure of montmorillonite. Furthermore, doping Ti can improve the adsorption ability and reduce the band gap of the photocatalyst, thus enhancing the photocatalytic degradation performance. When the Ti doping ratio was 4% (4TBM), the material dosage was 1.0 g/L, and the initial concentration was 20 mg/L, 4TBM has the best photocatalytic degradation effect on reactive brilliant blue KN-R, with a removal rate of 98.17%. The photocatalytic degradation process of reactive brilliant blue KN-R follows the first-order kinetic model. This study not only has great significance for environmental remediation but also provides an optical material with excellent performance for the optical field. [ABSTRACT FROM AUTHOR]

Infective diseases are becoming more popular, and managing them has become a great worry for humanity. A rubber nanocomposite based on nitrile butadiene rubber with graphene oxide (NBR/GO) and GO/nanoclay (montmorillonite, MMT) (NBR/GO/MMT) was fabricated by a simple technique, roll milling. The synergistic influence of the existence of GO, clay, and electron beam (EB)-radiation on the NBR nanocomposites was characterized using scanning electron microscopy (SEM), and Fourier-transform infrared (FT–IR) techniques to study the mechanical, thermal, and antibacterial properties. The antibacterial activity of the prepared rubber nanocomposites was estimated via the disk diffusion process against Gram-positive bacteria, Bacillus subtilis, Staphylococcus lentus, and Gram-negative bacteria ; Pseudomonas aeruginosa and Proteus mirabilis. The results demonstrated that the physico-mechanical performance was significantly reinforced by incorporating nano GO (6 phr) and clay with GO (3 phr/6 phr. NBR films have no antibacterial potential. GO increases the antibacterial efficiency of the NBR films. NBR/3% GO/3% clay film is the most effective in reducing bacterial growth and B. subtilis was the most sensitive bacteria for rubber treatments. The inhibition zone diameters of the un-irradiated and irradiated NBR/3% GO/3% clay films for B. subtilis were 18.03 ± 0.59 and 25.63 ± 0.98 mm, respectively. It could be concluded that because of its outstanding flexibility and human-body compatibility penetration, rubber in corporation with antimicrobial agents can be utilized for manufacturing medical and environmental products. [ABSTRACT FROM AUTHOR]

Development of a carrier with controlled release manner for methotrexate (MTX), an anticancer drug with short elimination half-life of 3-10 h, is important to overcome undesired side effects of conventional systems. This study demonstrated the synthesis of a pH-sensitive magnetic hydrogel nanocomposite based on montmorillonite (MMT), magnetite (Fe3O4), and alginate (Alg) for extended release of MTX. MMT-Fe3O4 with different amounts of MMT, were prepared by growth of Fe3O4 nanoparticles on the surface of MMT. Then, the MMT-Fe3O4-MTX-Alg nanocomposite beads were prepared by coating of well dispersed MMT-Fe3O4-MTX with Alg. The characterization was investigated using FTIR, XRD, DLS, FESEM-EDX, TGA, and VSM techniques. By introducing 1 g of MMT in hydrogel beads, the encapsulation efficiency and loading content were enhanced to 99.34% and 18.71%, respectively. Pure drug exhibits a burst release of 100% within 4 h. Whereas for MMT (1)-Fe3O4-MTX-Alg, less burst release of 12.4% and 27.6% in the gastric and intestinal fluid was obtained, respectively within 4 h. This phenomenon leads to the beads remaining intact passing through the stomach, but the release rate is done at an acceptable rate at the relatively alkaline environment of the intestine. The release kinetics of MTX from the nanocomposite beads follows the Korsmeyer-Peppas model. Finally, MTT assay and RT-PCR analysis were followed on MDA-MB-231 breast cancer cells, to assess their anti-proliferative, apoptotic and antiapoptotic effects. MMT-Fe3O4-MTX-Alg significantly reduced the percentage of viable cells, with a high down-regulation in the expression level of the anti-apoptotic gene (Bcl-2), and up-regulation in the apoptotic gene (Bax). [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) has gained significant attention as an environmentally friendly biopolymer, but its limited mechanical properties have hindered broader applications. Nanoparticles such as montmorillonite (MMT) offer a promising approach to address this limitation. The intercalation of MMT with polymer chains can significantly impact the mechanical properties of the nanocomposites. Hence, this paper investigated the effect of surface-modified montmorillonite (MMT) nanoparticles on the mechanical properties of polylactic acid (PLA) nanocomposites. The acetylation process of MMT was carried out followed by neutralisation process with NaOH. PLA granules and acetylated-modified MMT were mixed, crushed into granular form, and moulded. The effect of varying concentrations of modified MMTs on the tensile strength, elongation at break, and maximum force of PLA/MMT nanocomposites was evaluated using the ASTM D638 standard. FTIR results showed shifts in peak intensities in regions 2750 cm-1-2810 cm-1 led to changes in the aliphatic and aromatic regions, which confirmed the presence of acetylation. Controlled surface modification improved interfacial interactions and load distribution, enhancing overall mechanical performance. The incorporation of surface-modified MMT in PLA/MMT nanocomposite increased the maximum force, Young's modulus, elongation at breaks and tensile strength. PLA/1wt% MMT and the PLA/7wt% MMT compositions exhibited good mechanical properties. However, the PLA/5 wt% MMT blend is deemed more suitable for food applications, such as disposable cups, plates, and cutleries, due to its lower elongation point. In conclusion, the hydrophilic properties of MMT and the hydrophobic properties of PLA are compatible due to the synergistic effects during surface modification which enhance the overall performance of the nanocomposites. [ABSTRACT FROM AUTHOR]

Oral delivery of proteins faces challenges due to the harsh conditions of the gastrointestinal (GI) tract, including gastric acid and intestinal enzyme degradation. Permeation enhancers are limited in their ability to deliver proteins with high molecular weight and can potentially cause toxicity by opening tight junctions. To overcome these challenges, we propose the use of montmorillonite (MMT) as an adjuvant that possesses both inflammation-oriented abilities and the ability to regulate gut microbiota. This adjuvant can be used as a universal protein oral delivery technology by fusing with advantageous binding amino acid sequences. We demonstrated that anti-TNF-α nanobody (VII) can be intercalated into the MMT interlayer space. The carboxylate groups (-COOH) of aspartic acid (D) and glutamic acid (E) interact with the MMT surface through electrostatic interactions with sodium ions (Na+). The amino groups (NH2) of asparagine (N) and glutamine (Q) are primarily attracted to the MMT layers through hydrogen bonding with oxygen atoms on the surface. This binding mechanism protects VII from degradation and ensures its release in the intestinal tract, as well as retaining biological activity, leading to significantly enhanced therapeutic effects on colitis. Furthermore, VII@MMT increases the abundance of short-chain fatty acids (SCFAs)-producing strains, including Clostridia, Prevotellaceae, Alloprevotella, Oscillospiraceae, Clostridia_vadinBB60_group, and Ruminococcaceae, therefore enhance the production of SCFAs and butyrate, inducing regulatory T cells (Tregs) production to modulate local and systemic immune homeostasis. Overall, the MMT adjuvant provides a promising universal strategy for protein oral delivery by rational designed protein. [ABSTRACT FROM AUTHOR]

AbstractTo improve the epoxy bonding properties of polyphenylene sulfide (PPS) matrix composites, CK-MMT and K-BF were prepared by modifying montmorillonite (MMT) and basalt fiber (BF) with cetyl trimethyl ammonium bromide (CTAB) and 3-Glycidyloxypropyltrimethoxysilane (KH-560) as the modifiers. CK-MMT/BF/TPU/PPS composites were prepared by injection moulding. The surface properties of the composites were tested and characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), etc. The epoxy bonding and mechanical properties were studied by combining the single-lap-joint tensile shear strength test and notched impact test. The results demonstrated the successful preparation of the modified MMT and BF. With the addition of CK-MMT and K-BF in different ratios, the surface roughness and the contents of polar groups of the composites increased, which could effectively improve the epoxy bonding properties of PPS matrix composites. When the additions of CK-MMT and K-BF were 10 and 25 wt%, respectively, the composites had the best overall properties. It demonstrated a single-lap-joint tensile shear strength was 7.56 MPa, representing a 220.34% increase over that of thermoplastic polyurethane/polyphenylene sulfide (TPU/PPS) and a 477.10% increase over that of pure PPS. [ABSTRACT FROM AUTHOR]

Comprehensive Summary A new fluorescent fingerprint powder (DFF‐MMT) was formulated by blending cyclic chalcone dye DFF with montmorillonite (MMT), which can develop latent fingerprints (LFPs) with exceptional resolution and contrast on various surfaces, including ordinary glass, tin foil, marble, LED screens, and materials with distinct colors and fluorescent backgrounds. The fluorescence of DFF‐MMT transforms from orange to bright yellow with LFPs, allowing for a flawless visualization of fingerprints on uneven surfaces or materials with static electricity. Impressively, fingerprints developed by DFF‐MMT can be stored for over 21 months and conveniently duplicated. The developed LFPs by DFF‐MMT still keep high quality under the influence of aquatic condition, illumination and thermal effects. DFF‐MMT also exhibits benefits, such as affordability, real‐time, high‐resolution, high‐contrast development and no damage to DNA, making it an ideal choice for sophisticated criminal investigations. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSPolymer nanocomposites are increasingly used in insulation applications for enhanced electrical properties. However, there are intricate parameters that control the properties of the polymer, and hence investigations are required. This paper attempts to correlate the electrical properties of Epoxy/Organically modified montmorillonite clay composites with the free volume resulting from the incorporation of the Organically modified montmorillonite clay filler of 2, 5, and 7 weight per cent (wt.%). Positron annihilation spectroscopy has been used to compute the fractional free volume and free volume. The free volume percentage is observed to increase with the incorporation of 2 and 5 wt.% and reduces at 7 wt.%. A similar trend is observed in the average size of free volume. The filler increases the AC electric breakdown strength by 20%, arc resistance by 5%, and comparative tracking index by 10% at 5 wt.%. Thermal conductivity is seen to increase marginally with the filler. The surfaces of the composites are hydrophilic at 2 and 7 wt.%, and at 5 wt.%, it is hydrophobic. Longer durations of water diffusion render the surfaces of the nanocomposites hydrophobic. Fourier transform infrared spectroscopy investigations reveal broadening of peak, increase in peak intensity and stretching of Si–O–Si bonds at 5 wt.% of filler due to exfoliation. An attempt has been made to understand the results of electrical parameters based on the results of positron annihilation lifetime spectroscopy and thermal conductivity. Water diffusion is minimal at 5 wt.% of OMMT.Highest CTI of 588 is achieved at 5 wt.%.Arc resistance of 400 s is achieved at 5 wt.%. OMMT.Proof tracking is higher at 5 wt.% of OMMT.Surface is hydrophobic at 5 wt.% OMMT.Water diffusion is minimal at 5 wt.% of OMMT.Highest CTI of 588 is achieved at 5 wt.%.Arc resistance of 400 s is achieved at 5 wt.%. OMMT.Proof tracking is higher at 5 wt.% of OMMT.Surface is hydrophobic at 5 wt.% OMMT. [ABSTRACT FROM AUTHOR]

Background Aims and Methods Results Conclusions Fe and Al oxyhydroxides are well‐known phosphorus (P)‐retaining minerals in soils. Little information is available regarding the relevance of clay minerals for the sorption of P in mixed oxyhydroxide–clay mineral systems and pH effects on P sorption partitioning.We wanted to investigate pH effects on P sorption partitioning between Fe oxyhydroxides and high‐activity clay minerals in mixed‐mineral systems. We quantified the relative contribution of ferrihydrite or goethite versus Al‐saturated montmorillonite (Al‐MT) to the retention of orthophosphate (oPO4) and inositol hexakisphosphate (IHP) at different pH values (3–6). We combined the analysis of P solution concentration changes with the quantification of P bound to Fe(III) versus Al in the Fe oxyhydroxide/Al‐MT mixtures by X‐ray absorption near‐edge structure (XANES) spectroscopy.Orthophosphate was preferentially retained by ferrihydrite, compared to Al‐MT at pH 3–6. The opposite was observed for goethite at low P solution concentrations. The contribution of Al‐MT versus Fe oxyhydroxides to oPO4 retention increased with pH. This is attributed to a speciation change of clay‐adsorbed Al from monomeric Al3+ to polynuclear Al hydroxy species. IHP was predominantly retained by Al‐MT rather than ferrihydrite at pH 3–6, probably by the formation of adsorbed and surface‐precipitated Al phytate complexes.Synchrotron‐based XANES spectroscopy allows for quantifying P adsorbed to co‐existing pedogenic Fe(III) oxyhydroxides versus Al‐MT in mixed‐mineral systems. Soil P retention partitioning to these minerals depends on (1) dominating P form (oPO4, IHP), (2) relative abundance of high‐activity clay minerals, short‐range ordered and crystalline Fe oxyhydroxides, and (3) solution pH. [ABSTRACT FROM AUTHOR]

Partial oxidation of methane to methanol (POMM) is an economic and environmental technology, especially for utilizing low-concentration methane resources in the explosive range. In this paper, mineral clays like sepiolite (SEP), attapulgite (ATP), montmorillonite (MMT), bentonite (BEN), kaolin (KAO) and diatomite (DIA) were used as supports to prepare copper-based clay catalysts by impregnation method and their performance in continuous direct POMM with O 2 as oxygen source were tested. The methanol yields of these catalysts at 320 °C with feed ratio of CH 4 : O 2 : H 2 O = 2: 1: 8 exhibited the following order: Cu/KAO (145.26 μmol/g Cu /h) > Cu/ATP (74.18 μmol/g Cu /h) > Cu/SEP (63.99 μmol/g Cu /h) > Cu/MMT (51.59 μmol/g Cu /h) > Cu/DIA (42.29 μmol/g Cu /h) > Cu/BEN (39.64 μmol/g Cu /h). This demonstrated that copper-based clay catalysts were promising for use in POMM considering their economy and environmental acceptability. Additionally, these copper-based clay catalysts were characterized and it was found that different clays could tailor the interaction of Cu species with supports, alter the reducibility and surface acidity, thereby changing the methanol yield. What's more, it was confirmed that the superior methanol yield of Cu/KAO was attributed to its relatively more [Cu 2 O)]2+ sites with Cu–O, Cu–Si/Al and Cu–Cu coordination structures similar to that of copper-based zeolite catalysts. [Display omitted] • Explored the application of various clay materials in the methane to methanol. • Cu/KAO exhibited similar activity as copper-based zeolite catalysts. • EXAFS indicates that Cu/KAO has Cu–O, Cu–Si/Al and Cu–Cu coordination structures. • In-situ FT-IR indicates that methoxy is intermediate of methane to methanol. [ABSTRACT FROM AUTHOR]

In the present study, we give the proofs about important properties of Lambert azimuthal projection, for instance conformality, preserve area that important points for characterization. While there are some kind of Lambert projections in the literature (for instance standard, cylindrical), we utilize from the south polar aspect. In our proofs, we use the south polar aspect, and finally we give some visualizations of the inverse of projection as an example. [ABSTRACT FROM AUTHOR]

In this study, chitosan-based hydroxyapatite/chitosan (HAP/CHI), cellulose/chitosan (CEL/CHI) and montmorillonite/chitosan (MMT/CHI) composites were synthesized and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA). Acetylsalicylic acid (ASA) was used as a drug for loading and desorption studies to determine the release behavior of the synthesized composites. The maximum adsorption capacities (qe) were obtained as 251.5 mg/g, 197.7 mg/g and 288.95 mg/g for HAP/CHI, CEL/CHI and MMT/CHI, respectively. In vitro release studies of ASA from the composites HAP/CHI, CEL/CHI, and MMT/CHI were carried out phosphate buffer solution (PBS) and gastric juice (GJ). In the intestinal medium (PBS) controlled drug release continued for 72 hours (4320 minutes), and burst release was observed in the first 5 minutes in all composites. 19.16%, 47.15% and 37.32% of the active ingredient from HAP/CHI, CEL/CHI and MMT/CHI composites, respectively, were released in the first 5 minutes. After 5 minutes, the release slowed down and became more controlled for all three composites. At the end of the release, the highest releasing composite was CEL/CHI, with 95.77% ASA release. A total drug release of 87.48% was achieved with MMT/CHI and 87.37% with HAP/CHI. In the gastric environment (GJ) Controlled drug release continued for 72 hours (4320 minutes), and burst release was observed in the first 5 minutes in all composites. 52.51%, 72.30% and 44.87% of the active ingredient from HAP/CHI, CEL/CHI and MMT/CHI composites, respectively, were released in the first 5 minutes. After 5 minutes, the release slowed down and became more controlled for all three composites. At the end of the release, the highest releasing capacity was found with the CEL/CHI composite, with 96.05% ASA release. A total drug release of 93.26% was achieved with HAP/CHI and 84.89% with MMT/CHI. [ABSTRACT FROM AUTHOR]

The widespread use of clay minerals and clays in environmental engineering, industry, medicine, and cosmetics largely stems from their adsorption properties and surface charge, as well as their ability to react with water. The dissolution and growth of minerals as a function of pH are closely related to acid–base reactions at their surface sites and their surface charge. The vivid tapestry of different types of surface sites across different types of clay minerals generates difficulties in experimental studies of structure–property relationships. The aim of this paper is to demonstrate how a mesoscale stochastic kinetic Monte Carlo (kMC) approach altogether with atomistic acid-base models and empirical data can be used for understanding the mechanisms of dissolution and surface charge behavior of clay minerals. The surface charge is modeled based on equilibrium equations for de/protonated site populations, which are defined by the pH and site-specific acidity constants (pKas). Lowered activation energy barriers for these sites in de/protonated states introduce pH-dependent effects into the dissolution kinetics. The V-shaped curve observed in laboratory experiments is reproduced with the new kMC model. A generic rate law for clay mineral dissolution as a function of pH is derived from this study. Thus, the kMC approach can be used as a hypothesis-testing tool for the verification of acid–base models for clay and other minerals and their influence on the kinetics of mineral dissolution and growth. [ABSTRACT FROM AUTHOR]

Comprehending water molecules adsorption mechanism on clays is crucial to hydraulic fracturing technology application in clay-rich shale formation. In this research, the adsorption of water vapor on non-swelling of kaolinite (Kaol), swelling clay of montmorillonite (Mt), and their three different mixtures (75:25/Mt:Kaol, 50:50/Mt:Kaol and 25:75/Mt:Kaol) was studied. The effect of mixing ratio of Mt and Kaol on the adsorption process of water vapor was discussed. The obtained findings display that the swelling clay of Mt possesses the greater water vapor adsorption ability than the non-swelling clay of Kaol. Enhancing the mass ratio of Mt in the mixture can obviously improve the uptake for water vapor. For Mt, primary adsorption exhibits a more apparent effect on the adsorption of water vapor adsorption. For Kaol, the effect of secondary adsorption on water vapor adsorption is more significant. With increasing mass ratio of Kaol in the mixture, the difference between secondary adsorption and primary adsorption gradually decreases. The affinity of water vapor adsorption on Mt is the biggest, followed by 75:25/Mt:Kaol, 50:50/Mt:Kaol, 25:75/Mt:Kaol, and Kaol, in sequence. Mt has the highest surface potential, and surface potential for Kaol is the lowest. There is a positive relationship between surface potential and the mass ratio of Mt in the mixture. As the pressure increases, Gibbs free energy change quickly enhances and then decreases. The reduction of adsorption spontaneity on Kaol under high pressure is more manifest. Water vapor adsorption spontaneity on clay mixture is improved by enlarging mass ratio of Mt in the mixture. [ABSTRACT FROM AUTHOR]

The study examined the possibility of intercalation of montmorillonite with neomycin in an aqueous drug solution and the factors influencing the effectiveness of this process, such as the ion exchange capacity and process conditions, including the time and temperature of incubation with the drug. X-ray diffractometry (XRD), infrared spectroscopy (FTIR), thermal analysis (DSC/TG), and Zeta potential measurement were used to confirm drug intercalation as well as to investigate the nature of clay–drug interactions. The obtained conjugates with the most favorable physicochemical properties were also tested for antibacterial response against Gram-negative bacteria (Escherichia coli) to confirm that the bactericidal properties of neomycin were retained after intercalation and UV–VIS spectrophotometry was used to examine the kinetics of drug release from the carrier. The results of the conducted research clearly indicate the successful intercalation of neomycin in montmorillonite and indicate the influence of process parameters on the properties of not only the conjugates themselves but also the properties of the intercalated drug, particularly its bactericidal activity. Ultimately, a temperature of 50 °C was found to be optimal for effective drug intercalation and the conjugates obtained within 2 h showed the highest antibacterial activity, indicating the highest potential of the thus-obtained montmorillonite conjugates as neomycin carriers. [ABSTRACT FROM AUTHOR]

The composition of clay minerals in soils, and more particularly the presence of montmorillonite (as part of the smectite family), is a key factor in soil swell–shrinking as well as off–road vehicle mobility. Detecting these topsoil clay minerals and quantifying the montmorillonite abundance are a challenge since they are usually intimately mixed with other minerals, soil organic carbon and soil moisture content. Imaging spectroscopy coupled with unmixing methods can address these issues, but the quality of the estimation degrades the coarser the spatial resolution is due to pixel heterogeneity. With the advent of UAV-borne and proximal hyperspectral acquisitions, it is now possible to acquire images at a centimeter scale. Thus, the objective of this paper is to evaluate the accuracy and limitations of unmixing methods to retrieve montmorillonite abundance from very-high-resolution hyperspectral images (1.5 cm) acquired from a camera installed on top of a bucket truck over three different agricultural fields, in Loiret department, France. Two automatic endmember detection methods based on the assumption that materials are linearly mixed, namely the Simplex Identification via Split Augmented Lagrangian (SISAL) and the Minimum Volume Constrained Non-negative Matrix Factorization (MVC-NMF), were tested prior to unmixing. Then, two linear unmixing methods, the fully constrained least square method (FCLS) and the multiple endmember spectral mixture analysis (MESMA), and two nonlinear unmixing ones, the generalized bilinear method (GBM) and the multi-linear model (MLM), were performed on the images. In addition, several spectral preprocessings coupled with these unmixing methods were applied in order to improve the performances. Results showed that our selected automatic endmember detection methods were not suitable in this context. However, unmixing methods with endmembers taken from available spectral libraries performed successfully. The nonlinear method, MLM, without prior spectral preprocessing or with the application of the first Savitzky–Golay derivative, gave the best accuracies for montmorillonite abundance estimation using the USGS library (RMSE between 2.2–13.3% and 1.4–19.7%). Furthermore, a significant impact on the abundance estimations at this scale was in majority due to (i) the high variability of the soil composition, (ii) the soil roughness inducing large variations of the illumination conditions and multiple surface scatterings and (iii) multiple volume scatterings coming from the intimate mixture. Finally, these results offer a new opportunity for mapping expansive soils from imaging spectroscopy at very high spatial resolution. [ABSTRACT FROM AUTHOR]

Freeze-thaw effects can significantly alter the volume of expansive soil due to the water-phase change and soil expansion. The montmorillonite content was an important factor influencing the expansibility of expansive soil. This paper investigated the micropore structure characteristics of expansive soil under freeze-thaw cycles with various montmorillonite contents. In addition, the micropore evolution of expansive soils and relationship between the unfrozen water content and temperature were also examined via X-ray diffraction (XRD) and nuclear magnetic resonance (NMR). The results indicated that: (1) the montmorillonite content affected the pore size distribution of expansive soil, and with increasing montmorillonite content, the relaxation time (T2) distribution curves changed from single-peak into double-peaks; (2) after multiple freeze-thaw cycles, the macropores in expansive soil increased and mesopore pores decreased; (3) considering the freezing point and capillary adsorption, the soil freezing characteristic curve (SFCC) could be divided into four stages, namely, unfrozen water, free water, freezing-capillary water, freezing-hydroscopic water; (4) the montmorillonite content only affected the unfrozen water content from 0°C to −5°C, while at temperatures lower than −5°C, the effect of the montmorillonite content on the unfrozen water content was negligible. [ABSTRACT FROM AUTHOR]

Melamine polyphosphate (MP), a halogen-free flame retardant was utilized to prepare flame retardant enhanced montmorillonite (MP-MMT), which was introduced into polymethyl methacrylate (PMMA) by emulsion polymerization to improve its heat resistance and flame retardancy. The decorated PMMA were characterized by SEM, FTIR, XRD, and XPS, indicating that MP-MMT/PMMA composites were successfully prepared. The resulting composites exhibited excellent heat resistance, the temperature at maximum weight loss rate was increased from 360 °C to 377 °C, and the char residue at 500 °C was increased to 1.93%. In addition, the LOI value of PMMA composite system was increased from 17.2% to 22.4%, and MP-MMT/PMMA-3 achieved UL-94 V-1 rating. Compared with pure PMMA, the total heat release and peak heat release rate of MP-MMT/PMMA were reduced by 23.0% and 32.4%, respectively. The total smoke release of the optimal flame-retardant PMMA resin decreased by 22.1%, the CO production increased slightly, and the CO2 production decreased significantly. This indicates that the incorporation of MP-MMT has a good effect on flame retardancy. Finally, the flame retardant mechanism of MP-MMT to inhibit PMMA combustion was analyzed. The intercalation modification of MMT is potentially valuable for flame retardant studies of PMMA. [ABSTRACT FROM AUTHOR]

The current study investigates the production of organoclay suitable for use in the base section of a passenger tire with a cap/base tread construction. The process involved the purification and modification of two types of sodium bentonite clay with different mineral characteristics and ion exchange capacities using a single-step process. The modification process of purified bentonite suspensions was performed using a two-tailed long-chain alkyl quaternary ammonium salt surfactant, namely di (hydrogenated tallow alkyl) dimethyl ammonium chloride (AD2HT), and two one-tailed long-chain alkyl quaternary ammonium salt surfactants, namely cetyl-trimethylammonium chloride (CTAC) and octadecylamine chloride (ODA), in relatively low amounts of surfactant (0.95 CEC), along with polyethylene glycol (4% clay) as an auxiliary modifier. X-ray diffraction (XRD) showed that the interlayer spacing of organoclays significantly increases. In addition, the XRD pattern depends on the kind of surfactant and is independent of the type of bentonite clay. The resulting organoclays were added to the tread base section of a passenger tire using the melt masterbatch technique along with a silane coupling agent. An increase in curing maximum torque (8–15%), curing delta torque (6–14%), hardness (2–10%), static modulus 300 (2–18%), and dynamic storage modulus (11–30%) of the rubber composites was observed without significant change of resilience and loss factor of the composite at 2 Phr of organoclay loadings. The organoclays based on the AD2HT modifier exhibited better mechanical properties than those based on the ODA and CTAC surfactants. The dynamic storage modulus of composites increased by about 30% with only 2 Phr of AD2HT-modified bentonites. Furthermore, the performance of the organoclay was found to be independent of the primary particle size, iron content, and ion exchange capacity of the bentonite clay within the studied range. [ABSTRACT FROM AUTHOR]

Construction resting on soil and rocks containing montmorillonite (MMT) are prone to damage induced by swelling, which involves a significant release of energy. It is often desirable to enhance these soils to mitigate swelling potential, regulate volume changes, and manage energy release. Experimental findings suggest that increasing temperature is one method to improve these soils, with water content, initial volume, and boundary conditions also influencing the swelling mechanism. This study utilizes ab initio molecular dynamics calculations to explore changes in volume and energy within MMT unit cells at the nanoscale due to temperature variations. The response of unit cells of MMT with varying dimensions and quantities of water molecules to temperature is assessed under constrained and unconstrained conditions. Results indicate that the volume changes and energy release of unit cells in response to temperature are contingent upon the presence of water molecules. In unit cells containing water molecules, both energy and volume decrease with rising temperature, whereas in unit cells devoid of water molecules, energy decreases while volume increases as temperature rises. Given the inherent association of soils with water in natural settings, it can be deduced that increasing temperature presents a viable method for enhancing naturally occurring MMT-dominated soils. Density functional theory calculations demonstrate that alterations in the volume and energy of MMT stem from shifts in interactions among the minerals, cations, and water molecules, as well as intrinsic structural defects like isomorphic substitution and peroxy links within the unit cells. These modifications induce variations in charge carriers and electrical properties, consequently influencing volume and energy changes within MMT unit cells. Additionally, it was observed that the failure of peroxy links can significantly impact the optimal temperature selection for the thermal enhancement of MMT. [ABSTRACT FROM AUTHOR]

Polycarboxylate superplasticizer(PCE)is widely used for its excellent properties such as high water reduction rate, good dispersibility,long slump retention time and adjustable molecular structure. However,due to the increasing scarcity of highquality natural sand,the mud content in concrete aggregate is generally high,which seriously affects the effect of PCE in engi neering. Therefore,how to improve the compatibility of PCE and clay has become a key problem to be solved. In this review,the interaction mechanism between different clay minerals and PCE is discussed. The research results of improving the mud resistance of PCE in recent years are summarized in detail from the adjustment of side chain length,the change of side chain shape,the introduction of functional groups and the use of sacrificial agents,which provides reference for the further design and development of PCE. [ABSTRACT FROM AUTHOR]

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In recent years, antibiotics in aqueous solutions have drawn extensive attention due to their harmful effect on human health and the environment. In this study, efficient and rapid adsorption of two antibiotics, including tetracycline (TC) and cefazolin (CFZ) on synthesised montmorillonite (Mt)/nano zero-valent iron (nZVI)/graphene oxide (GO) from aqueous solutions was studied. The prepared adsorbent was characterised by scanning electron microscope (SEM), energy dispersive X-Ray (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and vibrating sample magnetometer (VSM). One-factor-at-a-time (OFAT) method was used to optimise the experimental factors. The maximum removal percentage was achieved at pH of 7, an adsorbent dosage of 0.4 g, contact time of 7 min = TC and 10 min = CFZ, initial concentration of 5 mg L−1, and a temperature of 298 K. The evaluation of isotherm models indicated that the Langmuir isotherm with a coefficient of determination (R2) value of 0.9992 for both antibiotics was selected as the best fitting model to describe the adsorption process. The maximum adsorption capacities (qmax) of Mt-nZVI-GO were obtained at 43.24 mg g−1 for TC and 20.36 mg g−1 for CFZ. Furthermore, the pseudo-second-order (PSO) kinetic model fitted well for TC (R2 = 0.9937) and CFZ (R2 = 0.9997). Thermodynamic parameters, i.e. adsorption Gibbs free energy (ΔG0), standard enthalpy (ΔH0), and standard entropy (ΔS0) were estimated. It was found that the adsorption had spontaneous and exothermic in nature. The results revealed that Mt-nZVI-GO could be used as a simple, efficient, and eco-friendly adsorbent for the simultaneous removal of contaminants in aqueous media. [ABSTRACT FROM AUTHOR]