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This work combines experimental and computational modeling studies for the preparation of a composite of metformin and an organoclay, examining the advantages of a Tunisian clay used for drug delivery applications. The clay mineral studied is a montmorillonite-like smectite (Sm-Na), and the organoclay derivative (HDTMA-Sm) was used as a drug carrier for metformin hydrochloride (MET). In order to assess the MET loading into the clays, these materials were characterized by means of cation exchange capacity assessment, specific surface area measurement, and with the techniques of X-ray diffraction (XRD), differential scanning calorimetry, X-ray fluorescence spectroscopy, and Fourier-transformed infrared spectroscopy. Computational molecular modeling studies showed the surface adsorption process, identifying the clay–drug interactions through hydrogen bonds, and assessing electrostatic interactions for the hybrid MET/Sm-Na and hydrophobic interactions and cation exchange for the hybrid MET/HDTMA-Sm. The results show that the clays (Sm-Na and HDTMA-Sm) are capable of adsorbing MET, reaching a maximum load of 12.42 and 21.97 %, respectively. The adsorption isotherms were fitted by the Freundlich model, indicating heterogeneous adsorption of the studied adsorbate–adsorbent system, and they followed pseudo-second-order kinetics. The calculations of ΔGº indicate the spontaneous and reversible nature of the adsorption. The calculation of ΔH° indicates physical adsorption for the purified clay (Sm-Na) and chemical adsorption for the modified clay (HDTMA-Sm). The release of intercalated MET was studied in media simulating gastric and intestinal fluids, revealing that the purified clay (Sm-Na) and the modified organoclay (HDTMA-Sm) can be used as carriers in controlled drug delivery in future clinical applications. The molecular modeling studies confirmed the experimental phenomena, showing that the main adsorption mechanism is the cation exchange process between proton and MET cations into the interlayer space. [ABSTRACT FROM AUTHOR]

Adsorptive nanofiber electrospun membranes (ANEMs) show promise for heavy metal removal, particularly in dilute solutions. Nanofibrous polyacrylonitrile (PAN) membranes incorporating Cloisite 20A (C20) organoclay were fabricated via electrospinning for As(V) removal. The impact of C20 on structural properties and As(V) removal efficiency of the nanofiber membranes was investigated. The results indicated that the PAN‐C20 membranes morphology was uniform, with fiber diameters mostly falling within the 100–300 nm range. Incorporation of C20, especially in an exfoliated structure, led to increased hydrophilicity, mechanical strength, and roughness of the membranes. Batch adsorption results revealed that the adding C20 up to 1.5 wt.% significantly enhanced adsorption capacity due to the higher concentration and proper C20 dispersion. Dynamic filtration showed that the PAN‐C20(1.0) membrane achieved over 90% As(V) removal efficiency for 960 min and demonstrated excellent regeneration ability. Highlights: Cloisite 20A organoclay was incorporated into PAN by electrospinning to prepare adsorptive membrane.Adsorptive membranes were used for As(V) removal from water.Type of Cloisite 20A dispersion in PAN in dynamic filtration was more important than in static adsorptionPAN‐C20‐1.0 with exfoliated structure showed higher removal efficiency than PAN‐C20‐1.0 with intercalated structure.PAN‐C20‐1.0 membrane was usable for multiple adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

This study focuses on polyamide 6/organo-modified montmorillonite (PA6/OMMT) nanocomposites as potential liner materials, given the growing interest in enhancing the performance of type IV composite overwrapped hydrogen storage pressure vessels. The mechanical properties of PA6/OMMT composites with varying filler concentrations were investigated across a temperature range relevant to hydrogen storage conditions (−40 °C to +85 °C). Liner collapse, a critical issue caused by rapid gas discharge, was analyzed using an Ishikawa diagram to identify external and internal factors. Mechanical testing revealed that higher OMMT content generally increased stiffness, especially at elevated temperatures. The Young's modulus and first yield strength exhibited non-linear temperature dependencies, with 1 wt. per cent OMMT content enhancing yield strength at all tested temperatures. Dynamic mechanical analysis (DMA) indicated that OMMT improves the storage modulus, suggesting effective filler dispersion, but it also reduces the toughness and heat resistance, as evidenced by lower glass transition temperatures. This study underscores the importance of optimizing OMMT content to balance mechanical performance and thermal stability for the practical application of PA6/OMMT nanocomposites in hydrogen storage pressure vessels. [ABSTRACT FROM AUTHOR]

Injection moulded specimens were produced from biodegradable poly(butylene succinate) (PBS)/organomodified montmorillonite (OMMT) nanocomposites, after melt compounding in different compositions. WAXD studies demonstrated that the OMMT formed similar intercalation levels in the 2.5–10 w/w% additive ratio range. It was also proved by rotational rheometry that the nanoclay stacks form physical network above 5 w/w% concentration, which significantly influence the viscoelastic properties of the melt. The value of zero shear viscosity also changed accordingly, starting to increase above 5 w/w% nanoclay content. The OMMT content reduced the creep sensitivity measured in molten state.X-ray and DSC investigations showed that OMMT inhibits the crystallisation of PBS, resulting in a decrease in crystallinity at higher nanoclay ratios. As a result, the room temperature creep increased with the OMMT ratio.The Young's modulus linearly increases in the entire concentration range exceeding 1.2 GPa at 10 w/w% nanoclay content. The value of yield strength does not change significantly (35–40 MPa), but the strain at yield – which characterises stiffness – and the notched Izod impact strength already decrease at 2.5 w/w% OMMT content, but further increasing the nanoclay content has minor effect. However, the nanocomposite with 10 w/w% OMMT can be a real alternative to polypropylene (PP) and high-density polyethylene (HDPE) injection moulded products based on its mechanical properties.To characterise the effect of OMMT on dynamic mechanical properties, the S (Stiffening effectiveness), L (Loss effectiveness) and D (Damping effectiveness) indices were introduced to quantitatively describe the nanoclay effect intensity in each temperature range.

Two series based on poly(propylene 2,5-furandicarboxylate)-block-poly(tetramethylene oxide) (PPF-b-F-PTMO) containing carbon and mineral nanofillers that differ in shape (1D and 2D) were synthesized via in situ polymerization. The influence of the addition of the 1D-type nanoparticle, i.e., carbon nanofibers (CNFs) and halloysite nanotubes (HNTs), and the so-called 2D-type, i.e., graphene nanoplatelets (GNPs) and organoclay (C20A), on the properties of a biobased block copolymer was analyzed. The dispersion of nanoadditives in the nanocomposites was determined using a scanning electron microscope (SEM). The thermal properties were studied employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The introduction of nanoparticles increased the crystallinity (Xc) and the mean values of tensile modulus (E) of the bionanocomposites. In turn, one observed that the decrease in the limited viscosity number (LVN) was visible along with incorporating nanoadditives. The synthesized polymer bionanocomposites reveal the mechanical properties of elastomers during mechanical testing. Moreover, the good processability of the obtained materials by injection molding combined with the comprehensive ability to change mechanical and thermal properties of PPF-b-F-PTMO by tailoring the type and content of the nanofillers can indicate their possible applications in packaging, automotive, sports, construction, and many other industries. [ABSTRACT FROM AUTHOR]

Pultruded fiber reinforced polymer composites used in civil, power, and offshore/marine applications use fillers as resin extenders and for process efficiency. Although the primary use of fillers is in the form of an extender and processing aid, the appropriate selection of filler can result in enhancing mechanical performance characteristics, durability, and multifunctionality. This is of special interest in structural and high voltage applications where the previous use of specific fillers has been at levels that are too low to provide these enhancements. This study investigates the use of montmorillonite organoclay fillers of three different particle sizes as substitutes for conventional CaCO3 fillers with the intent of enhancing mechanical performance and hygrothermal durability. The study investigates moisture uptake and kinetics and reveals that uptake is well described by a two-stage process that incorporates both a diffusion dominated initial phase and a second slower phase representing relaxation and deterioration. The incorporation of the organoclay particles substantially decreases uptake levels in comparison to the use of CaCO3 fillers while also enhancing stage I, diffusion, dominated stability, with the use of the 1.5 mm organoclay fillers showing as much as a 41.5% reduction in peak uptake as compared to the CaCO3 fillers at the same 20% loading level (by weight of resin). The mechanical performance was characterized using tension, flexure, and short beam shear tests. The organoclay fillers showed a significant improvement in each, albeit with differences due to particle size. Overall, the best performance after exposure to four different temperatures of immersion in deionized water was shown by the 4.8 mm organoclay filler-based E-glass/vinylester composite system, which was the only one to have less than a 50% deterioration over all characteristics after immersion for a year in deionized water at the highest temperature investigated (70 °C). The fillers not only enhance resistance to uptake but also increase tortuosity in the path, thereby decreasing the overall effect of uptake. The observations demonstrate that the use of the exfoliated organoclay particles with intercalation, which have been previously used in very low amounts, and which are known to be beneficial in relation to enhanced thermal stability, flame retardancy, and decreased flammability, provide enhanced mechanical characteristics, decreased moisture uptake, and increased hygrothermal durability when used at particle loading levels comparable to those of conventional fillers, suggesting that these novel systems could be considered for critical structural applications. [ABSTRACT FROM AUTHOR]

A new pore type, nano-scale organo-clay complex pore-fracture was first discovered based on argon ion polishing- field emission scanning electron microscopy, energy dispersive spectroscopy and three-dimensional reconstruction by focused ion-scanning electron in combination with analysis of TOC, Ro values, X-ray diffraction etc. in the Cretaceous Qingshankou Formation shale in the Songliao Basin, NE China. Such pore characteristics and evolution study show that: (1) Organo- clay complex pore-fractures are developed in the shale matrix and in the form of spongy and reticular aggregates. Different from circular or oval organic pores discovered in other shales, a single organo-clay complex pore is square, rectangular, rhombic or slaty, with the pore diameter generally less than 200 nm. (2) With thermal maturity increasing, the elements (C, Si, Al, O, Mg, Fe, etc.) in organo-clay complex change accordingly, showing that organic matter shrinkage due to hydrocarbon generation and clay mineral transformation both affect organo-clay complex pore-fracture formation. (3) At high thermal maturity, the Qingshankou Formation shale is dominated by nano-scale organo-clay complex pore-fractures with the percentage reaching more than 70% of total pore space. The spatial connectivity of organo-clay complex pore-fractures is significantly better than that of organic pores. It is suggested that organo-complex pore-fractures are the main pore space of laminar shale at high thermal maturity and are the main oil and gas accumulation space in the core area of continental shale oil. The discovery of nano-scale organo-clay complex pore-fractures changes the conventional view that inorganic pores are the main reservoir space and has scientific significance for the study of shale oil formation and accumulation laws. [ABSTRACT FROM AUTHOR]

Monolithic silica-based aerogels, produced with tetraethoxysilane (TEOS), reinforced with aramid fibers and incorporating aluminosilicates were prepared for the first time. The nanocomposites were obtained by varying the amount and type of aramid fibers and replacing a part of the synthetic Si (up to 35 wt% of Si) of TEOS by natural aluminosilicates, kaolin and palygorskite. The effects of the type and amount of both fiber and mineral in the materials key properties were investigated. Most samples displayed very low volumetric shrinkages during ambient drying (<5%), high porosity (∼90%), and low bulk densities, down to 120 kg m−3. Composites with both minerals exhibited superinsulating thermal performance, with thermal conductivity reaching values as low as 22 mW m−1 K−1, while also showing excellent thermal stability. The mechanical properties of the designed clay mineral-silica aerogels can be tailored, since the addition of short length fibers (Kevlar pulp) produces stiffer composites, while the longer fibers (Teijinconex) lead to more flexible ones. [ABSTRACT FROM AUTHOR]

This document discusses a research paper that proposes a modified method for evaluating the stability of deep excavations in soft clays. The discussion raises concerns about the proposed method and questions the assumptions made by the authors. It suggests alternative explanations for the observed behavior of excavations in soft clays and criticizes the models used in the study for not accurately representing actual ground movement patterns caused by excavation. The author invites the study authors to respond to these criticisms. [Extracted from the article]

The aim of this work was to synthesize and study the functional properties of polymer-clay nanocomposite (PCNCs) based on poly(sodium 4-styrene sulfonate) (NaPSS) and two types of clay in the dispersed phase: bentonite and kaolinite, in order to advance in the development of new geomimetic materials for agricultural and environmental applications. In this study, the effect of adding high concentrations of clay (10–20 wt. %) on the structural and functional properties of a polymer–clay nanocomposite was evaluated. The characterization by infrared spectroscopy made it possible to show that the PCNCs had a hybrid nature structure through the identification of typical vibration bands of the clay matrix and NaPSS. In addition, scanning electron microscopy allowed us to verify its hybrid composition and an amorphous particle-like morphology. The thermal characterization showed degradation temperatures higher than ~300 °C with Tg values higher than 100 °C and variables depending on the clay contents. In addition, the PCNCs showed a high water-retention capacity (>2900%) and cation exchange capacity (>112 meq/100 g). Finally, the results demonstrated the ability of geomimetic conditioners to mimic the structure and functional properties of soils, suggesting their potential application in improving soil quality for plant growth. [ABSTRACT FROM AUTHOR]

In recent years, clay-based organic thermosetting polyurethane polymer nanocomposites have more attracted attention in academia and industries because they exhibit different properties from conventional materials. In this study, we investigated novel thermoplastic Polyurethane (TPU) by adding nanoparticles of clay as a fire-retardant property. By employing an in-situ polymerization technique with a 2:1 ratio of tolylene 2,4-diisocyanate (TPI) and polyethylene glycol (PEG2000), the NCO terminated TPU prepolymer was created. Cloisite 25A (C25A), an organo-modified montmorillonite clay, was utilized to provide sufficient compatibility with the PEG/TPI matrix. The synthesized nanocomposite was examined using thermogravimetric analysis (TGA), SEM analysis, and X-ray diffraction (XRD). FTIR analysis provides information on functional groups. Compared to pure polyurethane, the nanocomposites showed superior thermal stabilities, as determined by thermogravimetric analysis (TGA). The results from X-ray diffraction and Scanning Electron Microscopy confirm the successful formation of an exfoliated polymer clay nanocomposite under all conditions, evidenced by the absence of the distinct peak (2θ = 4.79°) corresponding to the d-spacing of the organoclay. The relationship between clay loading and TPU matrix type and the mechanical characteristics of nanocomposites was examined. As the amount of clay in the Young's TPU/Cl25A nanocomposites grew, so did their tensile strength and modulus. The fire-retardant experiment was studied by a cone colorimeter. There have been notable advancements in the fire-retardant qualities, including smoke, CO output, and heat release rate. Comparing polyurethane integrated with 5-weight percent organoclay to ordinary polyurethane polymer, a noteworthy 53% reduction was observed. [ABSTRACT FROM AUTHOR]

In this study, the adsorption efficiency of low-cost raw and modified clay was investigated. The modified clay was characterized through various technics including X-ray diffraction, XRF spectroscopy, FT-IR spectroscopy, and Electron microscopy SEM to analyze the evolution of raw clay structure and morphology. Paracetamol was chosen as an adsorbate to evaluate the removal performance from the aqueous medium. Factors influencing the uptake of paracetamol, such as pH, equilibrium time, adsorbent dosage, and initial concentration of paracetamol, were examined. The results obtained showed that the raw clay was successfully modified by HDTMA, which increased adsorption capacity thanks to new hydrophobic interaction. The adsorption of paracetamol on the modified clay reached equilibrium at a contact time of 120 min. Isothermal and kinetic models used in this study showed that the adsorption followed the Langmuir-isotherm and pseudo-second-order kinetic models. The maximum experimental adsorption capacity predicted by Langmuir model is about 112.63 mg/g, which is much higher than that obtained for the unmodified sample (62.11 mg/g). These results show that modified natural Moroccan clay can be used as low-cost and eco-friendly adsorbent nanomaterials to remove emerging pharmaceutical contaminants from water. [ABSTRACT FROM AUTHOR]

The design and development of environmentally oriented cements with predominant content of widespread noncalcined precursors contribute to a more promising future for constantly evolving alkali-activated materials (AAMs). In this study, natural and designed blends of calcined clays and abundant raw calcium carbonate minerals were investigated as binary precursors for one-part AAMs using standard techniques, thermal, X-ray diffraction, and scanning electron microscopy/energy dispersive spectroscopy (EDS) analyses. The influencing factors to set optimal parameters were the mineralogical assemblage, precursors fineness, formulation details, means of alkali reactant incorporation, and curing regimes. It was stated that hydraulic one-part AAMs can be derived from calcined marl incorporated with limestone powder containing 5.8%–7.0% of calcined clay minerals and 54.6%–60.5% of calcite or nonhydraulic one-part AAMs from a mixture consisting of 20%–30% metakaolin and 70%–80% limestone powder. It was found that, compared with a metakaolin-limestone-based binary precursor, alkali activation of calcined marl–limestone results in the formation of a higher amount of binder gel with a greater extent of Ca incorporation into the structure of Na aluminosilicate gel and the formation of Ca aluminosilicate and Ca silicate hydrogels. This provides an alkali-activated calcined marl–limestone binder system with better mechanical properties and continuous strength development, including under wet conditions. [ABSTRACT FROM AUTHOR]

Responsive polymers can be combined with clay particles to form adaptable, or "tunable," clay–polymer composites. The purpose of this study is to investigate the potential for "tunability" of a nanocomposite at the mesoscale through changes in material properties—swelling behavior, Atterberg limits, hydraulic conductivity, and shear strength—with varying pH and ionic concentration of the surrounding fluid. The composite was synthesized from a nonionic form of the polymer polyacrylamide and an expansive clay, montmorillonite. An attempt was made to induce changes in behavior of the composite by exposing the material to a selected range of pH and ionic concentration conditions, thereby influencing the conformation (shape and size) of the responsive polymer molecules under different stress levels and solid contents. Behavior was compared for the cases of predicted coiled, partially extended, and extended conformation. The test results demonstrate that conformation of responsive polymer and tunability of composite depends primarily on solution type, stress levels, and solid content. The "tuning" response of a nanocomposite is maximized with a significant change in ionic concentration of the surrounding fluid. Nanocomposite swelling was 30% less than pure clay and had a friction angle 12° greater than pure clay at high ionic concentration. At low or high pH conditions, nanocomposite tunability was limited. [ABSTRACT FROM AUTHOR]

A new type of geopolymer with an iron–oxygen–silicon linkage is synthesized and reported for the first time. The aim was to enable the iron-rich clay material (laterite) as a raw material for the geopolymerization. Iron was used in different ratios ranging 1–3 wt. % in the raw mix designing geopolymer followed by activation with concentrated alkali solutions of NaOH and KOH in different concentrations. The bonding of Fe–O–Si was confirmed from the FTIR peaks in NaOH- and KOH-based geopolymers. X-ray diffraction studies confirmed the formation of zeolitic, sodalite, and almandite phases. The final product has shown a compressive strength of 2371.8 and 1503 kN/m2 and can be used as a construction material. [ABSTRACT FROM AUTHOR]

Polymer clay nanocomposites, which can exhibit many superior properties compared to virgin polymers, have gained increasing interest and importance in recent years. This study aimed to prepare composites of two organoclays with unusual ratios and different degrees of lyophilicity with low-density polyethylene and compare their textural structures and thermal and mechanical properties with those of virgin polymer. For this purpose, firstly, organoclays, hydrophobic and superhydrophobic organoclays (OC and SOC), were prepared by solution intercalation method using cetyltrimethylammonium bromide with and without addition of a hydrocarbon substance. Then, using both organoclays, polyethylene organoclay composites were prepared and characterized using X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Additionally, tensile and hardness tests were performed to determine the mechanical properties of the composites, and differential scanning calorimetry (DSC) thermograms were taken to examine their thermal behavior. XRD patterns and HRTEM images of hydrophobic and superhydrophobic organoclays and the composites show that the characteristic smectite peak of the clay shifts to the left and expands, that is, the interlayer space widens and, in the composites, it deforms immediately at low clay ratios. HRTEM images of the composites prepared especially with low clay ratios indicate that a heterogeneous dispersion of clay platelets occurs, indicating that nanocomposite formation has been achieved. On the contrary, in the composites prepared with high clay ratios, this dispersion behavior partially turns into aggregation. In the composites prepared using up to 20% by weight of superhydrophobic organoclay, extremely stable and continuous improvements in all mechanical properties were observed compared to those of the composites prepared using hydrophobic organoclay. This indicates that by using superhydrophobic organoclay, a ductile nanocomposite of polyethylene containing inorganic components in much higher than usual proportions can be prepared. [ABSTRACT FROM AUTHOR]

Clays and clay minerals are common natural materials, the unique properties of which have attracted the interest of the industry, especially because these materials are easily available, cheap, and non-toxic. Clays and clay minerals are widely used in many applications, such as in ceramic production, in the clarification of liquids, pollutant adsorbers, filler in composites and nanocomposites, soil amendments, in pharmacy, etc. This review assesses the development in the area of clay application in nanocomposites and ceramics. The first part of this study covers polymer/clay nanocomposites. Topics of interest include nanofiller sources for polymer nanocomposites, the possible ways of clay modification, polymer/clay nanocomposite classification and their processing, and polymer matrix overview with possible enhancement of nanocomposite properties. Some of the applications have already been commercialized. Approximately 80% of the polymer/clay nanocomposites are destined for the automotive, aeronautical, and packaging industries. The second part of this study describes ceramic materials with a focus on silicate ceramics. Talc and kaolinite represent the main natural raw materials for traditional ceramic applications. Less traditional cordierite, steatite, and forsterite could offer property enhancement and seem to be useful in electronics, electrical engineering, catalysts, solar thermal storage, or medical applications. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis of new nanocomposites (NCs) comprising polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) with silicon dioxide (SiO2 ) and chromium trioxide (Cr2O3 ) for the use in gammarays’-shielding applications. The nanocomposites exhibit desirable properties such as low weight, elasticity, high attenuation coefficients, and costeffectiveness for gamma-rays’ shielding. The structural properties of PVA–CMC–SiO2–Cr2O3 nanocomposites are studied. The scanning electron microscopy reveals that the top surface of the PVA–CMC/SiO2–Cr2O3 NCs films exhibits uniform and cohesive aggregates or fragments distributed randomly, when the weight percentage reaches 8%. The uniform distribution of nanoparticles (NPs) in the blend is evidenced by the optical microscope images and leads to a continuous network within the polymer matrix. The study results regarding the utilization of gamma-rays’ shielding demonstrate that the nanocomposites composed of PVA–CMC/SiO2–Cr2O3 display significant attenuation coefficients for gamma rays. [ABSTRACT FROM AUTHOR]

This study focuses on addressing the challenges associated with labor-intensive soil penetration resistance (SPR) measurements, which are prone to errors due to varying soil moisture levels. The innovative approach involves developing SPR estimation models using artificial neural networks (ANN) for soils with optimal moisture levels determined by van Genuchten (WG) calculations. Sampling and measurements were conducted at 280 points (0–30 cm depth), with an additional 324 samples used for model testing. Considering six scenarios, this study aimed to identify the best estimation model using key soil properties (sand, clay, silt, bulk density, organic carbon, and aggregate stability) in different combinations affecting SPR. Results from all ANN scenarios demonstrated satisfactory SPR estimation performance, with the sand and clay content scenario exhibiting the highest accuracy, characterized by a mean square error (MSE) of 0.0029 and a coefficient of determination (R2) value of 0.9707. This selected scenario were further validated with different test data, yielding an MSE of 0.7891 and an R2 value of 0.67. In conclusion, this study suggests that, by standardizing moisture levels through WG calculations, ANN-based SPR estimation can effectively be applied to soils with specific sand and clay contents. [ABSTRACT FROM AUTHOR]

The problem of goaf treatment has become more and more prominent, posing a significant risk to the safety of transportation and causing environmental damage if it is not treated properly. This study aims to conduct a comparative analysis of various grouting pastes and evaluate their application in goaf treatment according to grouting backfilling. This research begins by discussing different grouting pastes' properties, including clay-cement composite grouting material and geopolymer grouting material, which have excellent engineering performance, environmental friendliness, and are easy to operate in complex geological environments. Moreover, the factors affecting the performance of grouting pastes, such as water-solid ratio and curing time, are also examined. Based on detailed information about the boreholes provided by drilling television, a reasonable treatment plan is formulated for goaf treatment. Finally, this study evaluates the effectiveness of different grouting pastes in real-world goaf treatment projects. The study draws the following conclusions: a direct relationship exists among flowability, setting time as well as water-solid ratio. An inverse relationship exists between the compressive strength of grouting materials and the water-solid ratio. Drilling data reveals complex goaf structures with defects such as water leakage, collapse and cavity, indicating potential geological risks in shallow areas. A treatment plan is formulated based on the geological conditions of goafs by drilling television. The effectiveness of backfill grouting in goaf areas is inspected using ground-penetrating radar (GPR) technology, and results indicate that adjusting water-solid ratio of grouting material can improve treatment effects. [ABSTRACT FROM AUTHOR]

This study focuses on polyamide 6/organo-modified montmorillonite (PA6/OMMT) nanocomposites as potential liner materials, given the growing interest in enhancing the performance of type IV composite overwrapped hydrogen storage pressure vessels. The mechanical properties of PA6/OMMT composites with varying filler concentrations were investigated across a temperature range relevant to hydrogen storage conditions (−40 °C to +85 °C). Liner collapse, a critical issue caused by rapid gas discharge, was analyzed using an Ishikawa diagram to identify external and internal factors. Mechanical testing revealed that higher OMMT content generally increased stiffness, especially at elevated temperatures. The Young’s modulus and first yield strength exhibited non-linear temperature dependencies, with 1 wt. per cent OMMT content enhancing yield strength at all tested temperatures. Dynamic mechanical analysis (DMA) indicated that OMMT improves the storage modulus, suggesting effective filler dispersion, but it also reduces the toughness and heat resistance, as evidenced by lower glass transition temperatures. This study underscores the importance of optimizing OMMT content to balance mechanical performance and thermal stability for the practical application of PA6/OMMT nanocomposites in hydrogen storage pressure vessels.

Pultruded fiber reinforced polymer composites used in civil, power, and offshore/marine applications use fillers as resin extenders and for process efficiency. Although the primary use of fillers is in the form of an extender and processing aid, the appropriate selection of filler can result in enhancing mechanical performance characteristics, durability, and multifunctionality. This is of special interest in structural and high voltage applications where the previous use of specific fillers has been at levels that are too low to provide these enhancements. This study investigates the use of montmorillonite organoclay fillers of three different particle sizes as substitutes for conventional CaCO3 fillers with the intent of enhancing mechanical performance and hygrothermal durability. The study investigates moisture uptake and kinetics and reveals that uptake is well described by a two-stage process that incorporates both a diffusion dominated initial phase and a second slower phase representing relaxation and deterioration. The incorporation of the organoclay particles substantially decreases uptake levels in comparison to the use of CaCO3 fillers while also enhancing stage I, diffusion, dominated stability, with the use of the 1.5 mm organoclay fillers showing as much as a 41.5% reduction in peak uptake as compared to the CaCO3 fillers at the same 20% loading level (by weight of resin). The mechanical performance was characterized using tension, flexure, and short beam shear tests. The organoclay fillers showed a significant improvement in each, albeit with differences due to particle size. Overall, the best performance after exposure to four different temperatures of immersion in deionized water was shown by the 4.8 mm organoclay filler-based E-glass/vinylester composite system, which was the only one to have less than a 50% deterioration over all characteristics after immersion for a year in deionized water at the highest temperature investigated (70 °C). The fillers not only enhance resistance to uptake but also increase tortuosity in the path, thereby decreasing the overall effect of uptake. The observations demonstrate that the use of the exfoliated organoclay particles with intercalation, which have been previously used in very low amounts, and which are known to be beneficial in relation to enhanced thermal stability, flame retardancy, and decreased flammability, provide enhanced mechanical characteristics, decreased moisture uptake, and increased hygrothermal durability when used at particle loading levels comparable to those of conventional fillers, suggesting that these novel systems could be considered for critical structural applications.

The aim of this work was to synthesize and study the functional properties of polymer-clay nanocomposite (PCNCs) based on poly(sodium 4-styrene sulfonate) (NaPSS) and two types of clay in the dispersed phase: bentonite and kaolinite, in order to advance in the development of new geomimetic materials for agricultural and environmental applications. In this study, the effect of adding high concentrations of clay (10–20 wt. %) on the structural and functional properties of a polymer–clay nanocomposite was evaluated. The characterization by infrared spectroscopy made it possible to show that the PCNCs had a hybrid nature structure through the identification of typical vibration bands of the clay matrix and NaPSS. In addition, scanning electron microscopy allowed us to verify its hybrid composition and an amorphous particle-like morphology. The thermal characterization showed degradation temperatures higher than ~300 °C with Tg values higher than 100 °C and variables depending on the clay contents. In addition, the PCNCs showed a high water-retention capacity (>2900%) and cation exchange capacity (>112 meq/100 g). Finally, the results demonstrated the ability of geomimetic conditioners to mimic the structure and functional properties of soils, suggesting their potential application in improving soil quality for plant growth.

Abstract This study aimed to create CTAB-modified bentonite organoclay (Bt@CTAB) by mixing the naturally occurring mineral bentonite (Bt) with the cationic surfactant cetyltrimethylammonium bromide (CTAB). Elemental analysis, N2 adsorption–desorption isotherm, scanning electron microscopy (SEM), FTIR spectroscopy, XRD, and thermogravimetric (TGA) analysis have been employed to analyze both the unmodified Bt and the Bt@CTAB organoclay. The dye sorption onto Bt@CTAB organoclay was investigated in the batch and column modes using aqueous solutions of anionic food dyes, viz., Sunset yellow FCF (E110), Azorubine (E122), and Ponceau 4R (E124) (individually or in a mixture). Experimental variables affecting the adsorption process, such as initial dye concentration, contact time, temperature, pH, and adsorbent dose, are evaluated. From the kinetic investigations, the adsorption of E110, E122, and E124 dyes well matched the pseudo-second-order kinetic model. E110 and E122 dyes adsorption onto Bt@CTAB attained equilibrium in 120 min while attained in 240 min for E124. The investigated food dyes were expected to achieve maximum adsorption efficiencies at concentration of 100 ppm of (E110 and E124) and 150 ppm of (E124), an adsorbent dosage of 0.4 gL−1, and an initial pH 5. In addition, Langmuir model best fits the sorption isotherm data, with the maximum adsorption capacity at 303 K being 238 mg/g, 248.75 mg/g, and 358.25 mg/g for E110, E122, and E124, respectively. The Bt@CTAB organoclay can be regenerated up to the 4th cycle successfully. The thermodynamic studies revealed the spontaneous and exothermic nature of the adsorption of these anionic dyes onto Bt@CTAB organoclay. The prepared cationic Bt@CTAB organoclay was successfully applied for the removal of E110, E122, and E124 from real water samples, synthetic effluents, and colored soft drinks with a recovery (R%) higher than 95%. The plausible adsorption mechanism of E110, E122, and E124 onto Bt@CTAB organoclay is proposed to be due to electrostatic interaction and hydrogen bond formation. Finally, the present study shows that Bt@CTAB organoclay may be employed efficiently and effectively to remove anionic food dyes from a wide range of real water and colored soft drinks.

Montmorillonite clay was modified by pillaring with AlMn oxides in different Al/Mn ratios and intercalation of two kinds of N-containing polymers (i.e., chitosan (CS) and polyvinyl pyrrolidinone (PVP)) chains. The modified pillared montmorillonite clay (PM) showed a rich two-dimensional layered porous structure with tunable parameters, such as large interlayer spacing, high specific area, and large porous volume. They were then used as supports for Pd nanoparticles. As applied in coupling reactions of aryl halides with terminal alkynes, Pd@CS/AlMn-PM showed better comprehensive catalytic performance than Pd@PVP/AlMn-PM. This was mainly attributed to its higher specific area, stronger chelation to Pd species, and better solvent resistance. [ABSTRACT FROM AUTHOR]

The present study aims to synthesize a hybrid thin film with sol-gel process via dip-coating and spin-coating techniques. Prepared films are used in the elimination several pollutants using the photodegradation process. Used films are prepared by mixing polyvinyl chloride (PVC)/hydrophobic-modified clays (Hc). First, we modified natural bentonite (Bt) and sodium montmorillonite (Na-Mt) with a surfactant cetyltrimethylammonium bromide. incorporation of methylene blue (MB) as photosensitizers into Hc was realised with different percentage of hydrophobic clay/photosensitizers at ambient temperature and optimum pH for 3 h. Secondly, the PVC/modified clay thin films were elaborated with sol-gel technology, using two techniques for deposition: Dip-coating in dimethylformamide and spin-coating in tetrahydrofuran. We modified some parameters such as weight ratio polymer/modified clay, number of dipper, rotational velocity, viscosity of polymer solution, rotation time and ramping -up rate for optimum conditions. Prepared films are characterized by X-ray diffraction, scanning electron microscopy-X-ray fluorescence and Fourier-transform infrared spectroscopy, the obtained results show the good insertion of MB into different support. The deposition on PVC increase the distance basal of materials. The efficiency of our prepared films was evaluated through the degradation of some dyes such as tartrazine (TR) and methyl orange (MO), using photoreactor upon irradiation with visible light and air injection. The obtained results show a significant efficiency of the films in the degradation of MO and TR. The TR degradation yields obtained vary from 72% to 76% for films containing 5% MB, and a yield close to 99% for the degradation of MO. [ABSTRACT FROM AUTHOR]

When drilling into a reservoir, the drilling fluid containing bentonite is prone to solid phase invasion, causing serious damage to the reservoir, and the conventional API barite suspension stability is poor, which makes it easy to cause sedimentation and blockage. Therefore, in order to avoid accidents, we use ultrafine barite to obtain a good suspension stability. More importantly, the method of modifying zwitterionic polymers on the surface of nano-silica is used to develop a temperature-resistant and salt-resistant fluid loss reducer FATG with a core-shell structure, and it is applied to ultra-fine clay-free water-based drilling fluid (WBDF). The results show that the filtration loss of clay-free drilling fluid containing FATG can be reduced to 8.2 mL, and AV can be reduced to 22 mPa·s. Although the viscosity is reduced, FATG can reduce the filter loss by forming a dense mud cake. The clay-free drilling fluid system obtained by further adding sepiolite can reduce the filtration loss to 3.8 mL. After aging at 220 °C for 15 d, it still has significant salt tolerance, the filtration loss is only 9 mL, the viscosity does not change much, a thinner and denser mud cake is formed, and the viscosity coefficient of the mud cake is smaller. The linear expansion test and permeability recovery evaluation were carried out. The hydration expansion inhibition rate of bentonite can reach 72.5%, and the permeability recovery rate can reach 77.9%, which can meet the long-term drilling fluid circulation work in the actual drilling process. This study can provide guidance for technical research in related fields such as reservoir protection. [ABSTRACT FROM AUTHOR]

In an effort to mitigate the harm caused by the irregular use of agrochemicals, a safer release system using biopolymers is promising due to their availability, biodegradability, and eco-friendliness. Herein, controlled-release materials for NPK fertilizer were formulated using clay-based graft biopolymer composites. The clay soil sample was collected and classified through Skempton's laboratory tests for soils and used as filler in starch-grafted sodium alginate (ST-g-SAG) with different percentages of clay. The clay-based graft biopolymer composites were synthesized via a microwave-assisted method. The biopolymer composites were characterized by FTIR, SEM, and EDS. The materials were loaded with NPK fertilizer, and a leaching test was conducted via a conductometric method to ascertain their release capacities. Biodegradation studies and the effect of humidity on the release of the NPK fertilizer were studied. Results of classification studies of the clay show Ca-montmorillonite (Ca-MMT) type. The average percent graft yield of starch-grafted sodium alginate/Ca-MMT (ST-g-SAG/Ca-MMT) was 83%. The results from FTIR and EDS showed that OH-, COO-, and CONH2 were responsible for the absorption of water. The release profile of the active NPK in the biocomposites ranged from 1% to 103%. Biodegradation results also showed a significant breakdown in biopolymer structure and mass loss. The release of active NPK from the material was humidity-responsive. [ABSTRACT FROM AUTHOR]

The use of organically modified clays as nano-reinforcement in polymer matrices is widely investigated owing to their remarkable reinforcement at low filler loading. In this body of work, the nanocomposites were prepared by melt blending nanoclay with polyamide 11 (PA 11) utilising a twin-screw extruder in order to maximise the dispersion of clay particles within the matrix during compounding. The main aim of the work was to study the reinforcing effect of nanoclay within PA 11 using two micromechanical model namely Halpin-Tsai and Mori-Tanaka composite theories. These theories were used to predict the effective tensile modulus of PA 11 nanocomposites and the results were compared to the experimental data. In addition, the Halpin-Tsai model was used to predict the storage modulus and heat distortion temperature (HDT) of PA 11 nanocomposites. It was found that the tensile modulus for nanocomposites with a high clay aspect ratio exhibits up to 10% higher when compared to the nanocomposites with lower clay aspect ratio. Thus, it is believed that the combination of clay aspect ratio and modulus contributes to the super reinforcing effect of nanoclay within the PA 11 matrix. [ABSTRACT FROM AUTHOR]

Herein, bionanocomposites of chitosan (CS)/silver nanoparticle/organoclay/zinc oxide nanoparticle (CS/Ag/OC/ZnO) were prepared for antibacterial food packaging. This study examines the time variation in the AgNP synthesis method by comparing local (74-85% deacetylated) and commercial chitosan (75%-85% deacetylated) as a reducing and capping agent and seeks to reconstruct the optimum ratio formulations of AgNPs and ZnONPs in bionanocomposites for food packaging. The results reveal that the synthesis of AgNPs was successfully carried out using a local chitosan solution as a reducing and capping agent. The CS/Ag/OC/ZnO films exhibit structural, mechanical, and optical properties suitable for food packaging and antibacterial activity on Staphylococcus aureus and Escherichia coli. The relative inhibition zone increased with increasing numbers of AgNPs and ZnONPs. The inhibition zone values indicated that E. coli and S. aureus bacteria were sensitive to the film, namely 12.5 ± 1.5 mm, and 16 ± 0.0 mm, respectively. [ABSTRACT FROM AUTHOR]

The paper discusses the development of a multiscale computational model for predicting the permeability of multilayer protective films consisting of multiple polymeric and hybrid layers containing clay minerals as fillers. The presented approach combines three levels of computation: continuous, full atomic, and quantitative structure–property correlations (QSPR). Oxygen and water are chosen as penetrant molecules. The main predictions are made using the continuum model, which takes into account the real scales of films and nanoparticles. It is shown that reliable predictions of the permeability coefficients can be obtained for oxygen molecules, which is not always possible for water. The latter requires the refinement of existing QSPR methods and interatomic interaction potentials for the atomistic level of calculations. Nevertheless, we show that the maximum effect on permeability reduction from the addition of clay fillers to the hybrid layer can be achieved by using nanoparticles with large aspect ratios and a high degree of orientational order. In addition, the use of the hybrid layer should be combined with the use of polymer layers with minimal oxygen and water permeability. The constructed model can be used to improve the properties of protective coatings for food and drug storage and to regulate the gas permeability of polymeric materials. [ABSTRACT FROM AUTHOR]

This research evaluates the use of organoclay/alginate hydrogels in removing Acid Yellow 23 in a fixed-bed column and contributes to the application of these composites in the context of the adsorption of anionic dyes that are present in wastewater. An organobentonite (OBent) was synthesized and encapsulated in an alginate matrix, using Ca2+ ions as a crosslinking agent. Experiments in fixed-bed columns showed that breakthrough and exhaustion times were longer with increasing bed height, which decreased with increases in flow rate and initial dye concentration. The Thomas, Yoon–Nelson, and Adams–Bohart models were well fitted to the experimental data for the breakthrough curves with high Adj. R2 correlation coefficients and low values of χ2. The theoretical adsorption capacity of the organobentonite/alginate hydrogel calculated from the Thomas model was 0.50 ± 0.01 mg/g (equivalent to 30.97 mg/g OBent), and this was obtained by using a 15 cm (10.10 g) bed height, 1 mL/min flow rate, and a 45 mg/L input dye concentration. The bed was regenerated with a 0.5 M NaOH solution, and the reuse of the saturated column bed was studied for two adsorption–desorption cycles. The results obtained in this study suggest the potential use of an organoclay/alginate hydrogel for the adsorption of pollutants in continuous systems. [ABSTRACT FROM AUTHOR]

This work evaluates the chemical impact of polyethylene terephthalate (PET) as plastic waste material used in clayey soil improvement. The purpose of this work is to study the behaviour of PET added in different percentages in soil, and how it affects the chemical composition of soil by applying rapid ageing cycles. The thermal stability of the clay-PET mixtures using the thermogravimetric method was studied, and the impact of PET quantity on pH was measured. To detect the migration of PET degradation products to the soil gas chromatography with mass spectrometry (GC-MS) was used. The GC-MS analysis results indicate the presence of DIBP, the concentration increased proportionally with the amount of PET added to the clay. The thermogravimetric analysis shows a thermal degradation of the polymeric chain starting from 200 °C. [ABSTRACT FROM AUTHOR]

This study used ethylene‐propylene diene monomers (EPDM), an elastomer, to develop foams incorporating clay as filler using simple compounding, chemical foaming, and peroxide‐mediated light crosslinking methods. The low‐temperature batch mixer was employed for compounding azodicarbonamide (ADC) as a foaming agent, dicumyl peroxide (DCP) as a crosslinker, followed by compression molding for sheet preparation and the high‐temperature foaming process. Fourier transform infrared spectroscopy (FTIR) equipped with a hot stage attenuated total reflection (ATR) was employed to elucidate the ADC decomposition and foaming. The DCP (0.25 phr) content was optimized based on the foaming expansion ratio (>4) and stability, which was further optimized in conjuncture with clay to generate high‐performance composite foams. The incorporation of 1% organoclay enhances the expansion ratio and specific tensile strength by >7 and ~ 270%, respectively, compared with EPDM foams without clay while displaying a density of 0.11 g/cm3. Overall, the developed foaming process can be extended to other elastomeric polymers for various applications such as protective gears (e.g., helmets and shin guards), thermal/sound insulation, packaging/containment, footwear soles, oil absorption, etc. [ABSTRACT FROM AUTHOR]

In this study, proton‐conducting sulfonated polyether ether ketone (sPEEK) membranes including tungstic acid, organically modified montmorillonite, and silicon dioxide were prepared using solution casting method for direct methanol fuel cells. All obtained composite membranes had adequate thermal stability for fuel cells, and their surfaces became more hydrophilic due to the incorporation of additives. The ion exchange capacities of the composite membranes were found to be very close to the sPEEK membrane. While the proton conductivity of the sPEEK membrane was 8.6 mS cm−1, the addition of additives led to an enhancement in the proton conductivity values. Among the prepared composite membranes, sPEEK‐H2WO4‐5 had the highest proton conductivity (36.5 mS cm−1) which was comparable to Nafion117 in water at room temperature. On the other hand, the methanol permeabilities of the composite membranes were in the same order compared to sPEEK but showed minor changes depending on the added materials and their compositions. Among the membranes obtained by solution casting, sPEEK‐H2WO4‐5 was found to be the best composite membrane due to its high proton conductivity and acceptable methanol permeability. Layer‐by‐layer modified sPEEK membranes were also obtained in the study for comparison and it was found that sPEEK‐PAH/H2WO4‐2 displayed the best selectivity value. [ABSTRACT FROM AUTHOR]

Intending to provide efficient and compact wastewater remediation, the present work is exploiting and introducing a novel composite prepared from porous starch aerogel (PSA) and organically modified Ca-montmorillonite (OMMT) for the removal of dyes from aqueous samples. First, potato starch components were used as a hydrolysis precursor to obtain PSA. The organoclay samples were prepared by co-intercalation of octadecylamine (ODA) into Ca-MMT using a low-temperature melting procedure. Composites with different starch-to-organoclay ratios of 10:1, 1:1, and 1:10 were then prepared by a blending process in distilled water and used for methyl orange (MO) uptake. The removal of methyl orange dyes increased with the amount of organoclay in the PSA matrix. Characterization revealed that organoclay synergy improved the PSA surface chemistry, while an important improvement in textural properties and thermal stability was also observed. The composite’s efficiency was demonstrated by high removal capabilities towards MO in most experimental runs, with a maximum adsorption capacity beyond 344.7 mg/g. The fitting result showed that MO adsorption follows a monolayer adsorption model, and chemisorption was the rate-controlling step. Nonetheless, this study proved the great potential of PSA/OMMT in dyeing wastewater treatment. Furthermore, starch modification is proven as an effective approach to enhancing the performance of starch-derived adsorbents.

Poly(amic acid) (PAA), a precursor of polyimide (PI), is synthesized by reacting dianhydride 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride with diamine 3,3′-dihydroxybenzidine in N,N′-dimethylacetamide. Organoclays with different alkyl chain lengths were dispersed in PAA, and the weight percentages (wt%) of the organoclays varied. The PI hybrid films were prepared over multiple steps under heat treatment conditions. Bentonite (BTN) was used as the pristine clay, and octylamine (C8) and hexadecylamine (C16) were used to chemically modify the surface of BTN to obtain the desired organoclay samples. Organoclays C8-BTN and C16-BTN were dispersed in a PI matrix, and the organoclay content varied in the range of 1–9 wt%. The thermal, morphological, and optical properties of the PI hybrid films were investigated based on the organoclay content. Although the thermal stability of the PI hybrid film improved when a small amount of organoclay was added, it decreased when the nano-filler content exceeded a certain critical content. Specifically, in the hybrid containing C8-BTN, the critical content is 5 wt%, while in the hybrid with C16-BTN, the critical content is 7 wt%. In addition, the morphology of the clay dispersed in the matrix at the critical content showed the best dispersed phase. The physical properties (thermal characteristics, dispersibility, and optical transparency) of the PI hybrid film containing C16-BTN were better than those of the hybrid film containing C8-BTN. However, the thermal expansion of the C8-BTN hybrid was lower than that of the C16-BTN film at the same content.

The aggregation process of 2D nanofillers (organoclay and graphene oxide (GO)) is studied within the framework of micromechanical models. The degree of aggregation of these nanofillers, expressed as the number of individual plates in one aggregate (tactoid), is determined by the ratio of the nominal moduli of elasticity of the nanofiller and the matrix polymer. It is found that increasing the first of these moduli leads to an increase in the degree of aggregation, whereas increasing the second one, leads to its reduction. This means that it is practically impossible to obtain exfoliated (separate) graphene plates in a polymer matrix. Both the studied polymer/2D nanofiller nanocomposites are reinforced with separate nanofiller aggregates, which is the optimal variant of reinforcing them. [ABSTRACT FROM AUTHOR]

This study aimed to create CTAB-modified bentonite organoclay (Bt@CTAB) by mixing the naturally occurring mineral bentonite (Bt) with the cationic surfactant cetyltrimethylammonium bromide (CTAB). Elemental analysis, N2 adsorption–desorption isotherm, scanning electron microscopy (SEM), FTIR spectroscopy, XRD, and thermogravimetric (TGA) analysis have been employed to analyze both the unmodified Bt and the Bt@CTAB organoclay. The dye sorption onto Bt@CTAB organoclay was investigated in the batch and column modes using aqueous solutions of anionic food dyes, viz., Sunset yellow FCF (E110), Azorubine (E122), and Ponceau 4R (E124) (individually or in a mixture). Experimental variables affecting the adsorption process, such as initial dye concentration, contact time, temperature, pH, and adsorbent dose, are evaluated. From the kinetic investigations, the adsorption of E110, E122, and E124 dyes well matched the pseudo-second-order kinetic model. E110 and E122 dyes adsorption onto Bt@CTAB attained equilibrium in 120 min while attained in 240 min for E124. The investigated food dyes were expected to achieve maximum adsorption efficiencies at concentration of 100 ppm of (E110 and E124) and 150 ppm of (E124), an adsorbent dosage of 0.4 gL−1, and an initial pH 5. In addition, Langmuir model best fits the sorption isotherm data, with the maximum adsorption capacity at 303 K being 238 mg/g, 248.75 mg/g, and 358.25 mg/g for E110, E122, and E124, respectively. The Bt@CTAB organoclay can be regenerated up to the 4th cycle successfully. The thermodynamic studies revealed the spontaneous and exothermic nature of the adsorption of these anionic dyes onto Bt@CTAB organoclay. The prepared cationic Bt@CTAB organoclay was successfully applied for the removal of E110, E122, and E124 from real water samples, synthetic effluents, and colored soft drinks with a recovery (R%) higher than 95%. The plausible adsorption mechanism of E110, E122, and E124 onto Bt@CTAB organoclay is proposed to be due to electrostatic interaction and hydrogen bond formation. Finally, the present study shows that Bt@CTAB organoclay may be employed efficiently and effectively to remove anionic food dyes from a wide range of real water and colored soft drinks. [ABSTRACT FROM AUTHOR]

A method of montmorillonite modification with polar oligourethane containing reactive amino groups has been developed. It is shown that functionalized montmorillonite is capable of adding aromatic and aliphatic diisocyanates, as well as sequential addition of aromatic diisocyanates and glycerol, which is essential for montmorillonite application as filler for polymer materials. According to wide-angle X-ray scattering, interlayer distance d001 of montmorillonite in the obtained samples varies depending on nature of oligomer macromolecules in the interlayer space that is explained with different conformation and orientation of aromatic and aliphatic oligourethane fragments. [ABSTRACT FROM AUTHOR]

This review offers a summary of the epoxy-nanoclay nanocomposites research that has been performed. Epoxy-nanoclay nanocomposites have an across-the-board variety of aerospace, defense, construction, and automobile applications. Nanoclay is one of the ideal nano-reinforcement for epoxy because of its ease of workability, environmental accessibility, well-versed chemistry, and lower cost. The significant addition of a smaller quantity of nanoclay, mostly ≤5 wt.%, may efficiently improve polymer composites' properties. This review aims to provide a state-of-the-art overview of epoxy-nanoclay nanocomposites, including their preparation methods, mechanical, hygrothermal, and wear properties. The discussion highlights the nanoclay influence on the properties listed above and the morphology of epoxy-nanoclay nanocomposites. [ABSTRACT FROM AUTHOR]

The nature of interactions of a toxic dye, thioflavin T (TFT), with pristine clay (bentonite (Bet)), clay minerals (montmorillonite (Mnt) and vermiculite (Vt)) and their organically modified forms (OMnt, OBet and OVt) has been investigated in aqueous media, and a methodology was developed for the utilization of TFT-treated colored residues as nanopigments, without producing the second-generation waste materials. The uptake of TFT was found to be more in case of pristine clay and clay minerals than their organically modified forms. In case of Mnt, TFT was present in the interlayer region, as supported by XRD data, and on the surface as the surface charge of TFT-treated pristine Mnt became almost zero, as indicated by the change in zeta potential value (− 17.6 to − 0.03 mV). In case of Bet and Vt, TFT was found to be only on clay mineral's surface, as suggested by the change in zeta potential value (− 31 to − 0.6 mV in case of Bet and − 47 to − 0.04 mV in case of Vt). The corresponding increase in the particle size (158–443 nm in case of Bet and 145–460 nm in case of Vt) was also evocative of surface adsorption. In case of organically modified forms (OMnt, OBet and OVt), TFT was predominantly on the surface in all cases examined. The experimental data obtained during extractive removal of TFT using pristine and organically modified clays were best described with Langmuir adsorption isotherm model, whereas kinetic data are equipped with pseudo-second-order kinetic model. The intense yellow-colored solid material obtained after the extraction was used as colorant for the formation of polymer films with enhanced physico-chemical characteristics. These materials not only provide beautiful bright color but also prevent the accumulation of second-generation waste material. [ABSTRACT FROM AUTHOR]

To prevent the serious threat of textile wastewater, researchers have developed adsorption-based wastewater treatment using cheap, yet effective, adsorbent materials. Of which is natural bentonite, that has the advantages for adsorption due to its porous structure and functional groups but still suffers from its low affinity against anionic and hydrophilic azo dyes. Herein, we aimed of improving the affinity by amino acid tryptophan embedment into the locally isolated natural bentonite collected from Aceh Province, Indonesia. The prepared bentonite samples were characterized using Fourier transform infrared, X-ray diffraction, and scanning electron microscopy. Adsorptive removal was performed on naphthol blue black (NBB) in a batch system with variations of contact time, pH, and adsorbent dosage. The isotherm studies were carried out at optimum conditions (contact time=15 minutes; pH 1; adsorbent dosage=0.2 g) with several models including Langmuir, Freundlich, Sips, and Redlich-Peterson isotherm models. The characterization results revealed that the modification altered its functional group, crystallinity, and micro-surface morphology that add more benefits for adsorption. At optimum conditions, 99.2% NBB has been successfully removed from the aqueous solution. The isotherm studies suggested that the NBB adsorption onto the tryptophane-modified natural bentonite was dependent on Sips isotherm model (R2=0.999; root-meansquare-errors=1.11×10-4 mg/g). [ABSTRACT FROM AUTHOR]

Intending to provide efficient and compact wastewater remediation, the present work is exploiting and introducing a novel composite prepared from porous starch aerogel (PSA) and organically modified Ca-montmorillonite (OMMT) for the removal of dyes from aqueous samples. First, potato starch components were used as a hydrolysis precursor to obtain PSA. The organoclay samples were prepared by co-intercalation of octadecylamine (ODA) into Ca-MMT using a low-temperature melting procedure. Composites with different starch-to-organoclay ratios of 10:1, 1:1, and 1:10 were then prepared by a blending process in distilled water and used for methyl orange (MO) uptake. The removal of methyl orange dyes increased with the amount of organoclay in the PSA matrix. Characterization revealed that organoclay synergy improved the PSA surface chemistry, while an important improvement in textural properties and thermal stability was also observed. The composite's efficiency was demonstrated by high removal capabilities towards MO in most experimental runs, with a maximum adsorption capacity beyond 344.7 mg/g. The fitting result showed that MO adsorption follows a monolayer adsorption model, and chemisorption was the rate-controlling step. Nonetheless, this study proved the great potential of PSA/OMMT in dyeing wastewater treatment. Furthermore, starch modification is proven as an effective approach to enhancing the performance of starch-derived adsorbents. [ABSTRACT FROM AUTHOR]

Research on bionanocomposites has been developed, while its application as food packaging is still being explored. They are usually made from natural polymers such as cellulose acetate, chitosan (CS), and polyvinyl alcohol. Bionanocomposite materials can replace traditional non-biodegradable plastic packaging materials, enabling them to use new, high-performance, lightweight, and environmentally friendly composite materials. However, this natural polymer has a weakness in mechanical properties. Therefore, a composite system is needed that will improve the properties of the biodegradable food packaging. The aim of this mini-review is to demonstrate recent progress in the synthesis, modification, characterization, and application of bionanocomposites reported by previous researchers. The focus is on the preparation and characterization of CS-based bionanocomposites. The mechanical properties of CS-based food packaging can be improved by adding reinforcement from inorganic materials such as organoclay. Meanwhile, the anti-bacterial properties of CS-based food packaging can be improved by adding nanoparticles such as Ag and ZnO.

Nano-black carbon (NC) and partially de-aluminated kaolinitic clay (PDK) composite blend was investigated as an additive to mortar fabrication for improving of the compressive strength. PDK was obtained from aluminum sulphate of Egypt (ASCE). PDK was grounded with nanocarbon. PDK achieved a good pozzolanic activity, it reached 120 %. The experimental protocol included chemical and physical properties of the PDK/Nano-carbon (NCPDK) and the produced mortars. The effect of five weight ratios of NCPDK (0, 5, 10, 15 and 20 %) on the properties of the formed OPC mortars was investigated. Each ratio was tested with three contents of Nanocarbon (1, 2 and 3 %) by weight. The accelerating effect of NCPDK was clear on the initial setting time whereas it reduced by about 31 % and the final setting time reduced by 23 % at 10 % NCPDK. The reduction in the initial flowability of OPC mortar reached 2.7 and 6 % for 10 and 20 % replacement respectively of the OPC by NCPDK and After 60 minutes from mixing, the relative flowability loss was 68 % at 10 % NCPDK and 88 % at 0 % replacement. The compressive strength values of the produced mortars ranged between 46.2 and 50.7 MPa (EN 196-1), with a maximum improvement equal to 14.4 % using 10 % NCPDK. There was no significant change in the pH values of the mortar mixtures. According to the obtained results the composite NCPDK can be used as an additive material in mortar fabrication. The structure of the hardened mortar modified with 10% NCPDK was investigated by XRD, FTIR and TGA that assured formation of more CSH. Incorporation of Nano-carbon enhanced the compressive strength. [ABSTRACT FROM AUTHOR]

This work aimed to compare the coating protection efficiency of C-steel using two kinds of clay: a local Khulays clay (RCKh) from Saudi Arabia and a commercial clay (CCIn) from India. Clay-based polymer nanocomposites have a unique layered structure, rich intercalation chemistry, and availability at low cost. They are promising reinforcements for polymers. The raw clay for both clay types was washed before being treated with NaCl to produce sodium clay (NaC). The cationic surfactant cetylpyridinium chloride (CPC) was then used to convert the NaC into the organoclay (OC) form. Polystyrene/organoclay nanocomposites (PCNs) were prepared by combining different concentrations of organoclay (1%, 3%, and 5% OC) in toluene solvent and polystyrene (PS) as the matrix. To ensure the success of the PCN modification process, the organoclay and PCN films were characterized using a variety of techniques, including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The shifts in the FT-IR spectra after the CPC treatment of NaC confirmed the presence of CPC in the organoclay samples and the presence of OC in the PCNs. The exfoliated structure was obtained from the XRD spectrum for low clay loading (1–3% PCN), while the intercalated structure was the dominant form for the 5% PCN. The XRD results were confirmed by TEM images. To calculate the coating efficiency of the PCNs, various electrochemical methods were used. The electrochemical measurements included electrochemical impedance spectroscopy (EIS), the electrochemical frequency modulation (EFM) method, and Tafel plots. The PCN with a concentration of 1 wt.% OC has a fully exfoliated structure and higher coating efficiency than the PCNs with partially exfoliated structures (3 wt.% and 5 wt.%). It was found from the Tafel plots that commercial Indian clay has better corrosion protection (81.4%) than local Khulays clay (60.2%). A comparison with other studies using current density values shows that our results are superior to those of many studies. [ABSTRACT FROM AUTHOR]

Polyethylene materials are of great interest to be used in many applications due to their many advantageous characteristics. It is light, highly chemical resistant, easy to process, low in cost and has good mechanical properties. Polyethylene is widely used as a cable-insulating material. However, research is still needed to further improve its insulation quality and properties. In this study, an experimental and alternative approach through a dynamic modeling method was conducted. The main objective was to investigate the effect of modified organoclay concentration on the properties of polyethylene/organoclay nanocomposites by observing their characterization and optical and mechanical properties. The thermogram curve reveals that 2 wt% organoclay used has the highest crystallinity (46.7%) while the highest amount of organoclay used produced the lowest crystallinity (31.2%). The presence of cracks was also observed mostly in the nanocomposite with higher content of organoclay, usually where 2.0 wt% and above of organoclay was used. Morphological observation from simulation results supports the experimental work. Only small pores were observed to form in lower concentrations, and as the concentration was increased to 2.0 wt% and above, the pores present became larger in size. Increasing the concentration of organoclay up to 2.0 wt% reduced the interfacial tension while increasing the concentration above 2.0 wt% did not bring any changes to the interfacial tension value. Different formulations produced different behavior of nanocomposite. Hence the control of the formulation was important to control the final result of the products for appropriate application in different sectors of industry. [ABSTRACT FROM AUTHOR]

The present study aims to explore the impact of pristine and surfactant-modified clays (montmorillonite, bentonite and vermiculite) on the thermomechanical properties of a poly (vinyl chloride) (PVC) polymer film. Initially, clay was modified by employing the ion exchange method. The modification of clay minerals was confirmed by the XRD pattern and thermogravimetric analysis. Pristine PVC polymer film and clay (montmorillonite, bentonite and vermiculite)-based PVC polymer composite films were fabricated using solution casting. The ideal dispersion of surfactant-modified organo-clays was observed in the PVC polymer matrix due to the hydrophobic nature of modified clays. The resultant pure polymer film and clay polymer composite film were characterized using XRD and TGA, and their mechanical properties were determined using a tensile strength tester and Durometer. From the XRD pattern, the intercalation of the PVC polymer film was found in the interlayer of organo-clay while exfoliation or partial intercalation and exfoliation were observed for pristine clay mineral-based PVC polymer composite films. Thermal analysis indicated a lowering of the decomposition temperature of the composite film as clay promotes the thermal degradation temperature of PVC. Improvement in the tensile strength and hardness was found to be more frequent in the case of organo-clay-based PVC polymer films, which is only due to the hydrophobic nature of organ clays, resulting in greater compatibility with the polymer matrix. [ABSTRACT FROM AUTHOR]