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Polymer nanocomposites have found wide industrial applications, necessitating optimal mechanical and fracture properties evaluation, traditionally done through costly experimental methods. This study employs machine learning, particularly XGBoost, to predict properties like tensile and fracture properties swiftly, aiding material innovation across industries. The research investigates unvulcanized and vulcanized polypropylene (PP)/ethylene propylene diene monomer (EPDM) reinforced with clay and halloysite nanoparticles (HNT), analyzing fracture properties via essential work of fracture (EWF). Experimental design selects tests, and an XGBoost model predicts tensile strength and modulus, strain at break, EWF, and non‐EWF based on EPDM and nanoparticle percentages, composite and nanoparticle types. The model accurately predicts tensile strength and modulus but less so for strain at break, EWF, and non‐EWF. Mean Absolute Percentage Error values for training/test are 0.49/1.21, 1.05/1.55, 34.21/42.76, 3.02/14.35, and 2.89/3.78, with determination coefficients of 0.99/0.98, 0.99/0.97, 0.97/0.91, 0.97/0.79, and 0.92/0.73. Nanoparticles mainly affect outputs, with EPDM secondarily impactful, while composite and nanoparticle types exhibit similar significance. The best‐performing polymer nanocomposite is a dynamically vulcanized one containing 10 wt% EPDM and 3 wt% clay, achieving tensile strength of 25.070 MPa, tensile modulus of 261.170 MPa, EWF of 75.300 N/mm, and non‐EWF of 10.150 N/mm2. Highlights: The effects of ethylene propylene diene monomer (EPDM), clay and halloysite nanoparticles on the mechanics of polypropylene‐based nanocomposites.Essential work of fracture (EWF) was used to study the fracture properties.Machine learning was employed to predict all mechanical characteristics.The vulcanization process improved all mechanical characteristics.The best compound: vulcanized one containing 10 wt% EPDM and 3 wt% clay. [ABSTRACT FROM AUTHOR]

Polyurethane incorporated with nanofillers such as carbon nanotubes, basalt fibers, and clay nanoparticles has presented remarkable potential for improving the performance of the polymeric composites. In this study, the halloysite nanofiller-reinforced polyurethane elastomer composites were prepared via the semi-prepolymer method. The impact of different halloysites (halloysite nanotubes and halloysite nanoplates) in polyurethane composites was investigated. Scanning electron microscopy, X-ray diffraction, infrared spectroscopy, electronic universal tensile testing, and acoustic impedance tube testing were employed to characterize the morphology, composition, phase separation, mechanical properties, and sound insulation of the samples. The composite fabricated with 0.5 wt% of halloysite nanotubes introduced during quasi-prepolymer preparation exhibited the highest tensile strength (22.92 ± 0.84 MPa) and elongation at break (576.67 ± 17.99%) among all the prepared samples. Also, the incorporation of 2 wt% halloysite nanotubes into the polyurethane matrix resulted in the most significant overall improvements, particularly in terms of tensile strength (~44%), elongation at break (~40%), and sound insulation (~25%) within the low-frequency range of 50 to 1600 Hz. The attainment of these impressive mechanical and acoustic characteristics could be attributed to the unique lumen structure of the halloysite nanotubes, good dispersion of the halloysites in the polyurethane, and the interfacial bonding between the matrix and halloysite fillers. [ABSTRACT FROM AUTHOR]

This study explores the potential of natural and recycled materials to enhance the fire behavior of eco-friendly intumescent coatings, compared to a traditional ammonium polyphosphate (APP)-based one. To achieve this, cork, halloysite clay, and recycled glass were evaluated as natural fillers and sustainable components within the coating formulation. The aim was to reduce the reliance on synthetic materials and minimize the environmental impact while maintaining fire performance. Fire exposure tests were conducted to assess the in situ char formation and its relationship to the heat source and char foaming process. The results highlighted that all functionalized coatings exhibited suitable intumescent behavior. The best results were evidenced by cork-filled coating that evidenced an intumescent capacity about 40% higher than the traditional ammonium polyphosphate (APP)-based one. This provided valuable insights into the coating's real-time response to fire, determining its suitability for various fire-resistant applications. [ABSTRACT FROM AUTHOR]

Halloysite nanotubes (HNTs) have attracted considerable attention due to their unique properties and wide range of applications. This review explores HNT‐based nanocomposites, focusing on their preparation methods and improvements in mechanical, thermal, and barrier properties. Various synthesis techniques, including solution mixing, melt compounding, in situ polymerization, and surface modification, are discussed, along with their benefits and limitations. The role of HNT characteristics such as aspect ratio, dispersion, and surface chemistry in enhancing nanocomposite properties is examined. HNTs significantly boost mechanical properties, including tensile strength, Young’s modulus, and toughness, due to their reinforcement effects. Improved dispersion and interfacial adhesion between HNTs and the polymer matrix enhance these properties. HNTs also act as thermal barriers, improving heat resistance and dimensional stability, while enhancing barrier properties against gases and moisture. These synergistic effects allow for the customization of nanocomposites for specific applications in packaging, automotive, electronics, and biomedical fields. Future research should focus on optimizing synthesis methods and processing techniques to further improve HNT‐based nanocomposites’ performance. This review provides a comprehensive overview of HNT‐based nanocomposites, offering valuable insights for advancing nanomaterials science and engineering. [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]

In this work, Hui-Shia model is developed to reveal the efficiency of a deficient interphase on the tensile modulus of polymer halloysite nanotube (HNT) nanocomposites. "Lc" as essential HNT length providing full stress transferring is defined and effective HNT size, effective HNT concentration, and efficiency of stress transferring (Q) are expressed by "Lc". Furthermore, the influences of all terms on the "Q" and nanocomposite's modulus are clarified, and also the calculations of the model are linked to the tested data of some nanocomposites. Original Hui-Shia model overpredicts the moduli, but the innovative model's predictions appropriately fit the measured data. Lc = 200 nm maximizes the sample's modulus to 2.6 GPa, but the modulus reduces to 2.11 GPa at Lc = 700 nm. Therefore, there is a reverse relation between the sample's modulus and "Lc". Q = 0.5 produces the system's modulus of 2.1 GPa, while the modulus of 2.35 GPa is achieved at Q = 1 providing a direct relation between the nanocomposite's modulus and "Q". Generally, narrow and big HNTs, along with a low "Lc", enhance the "Q", because a lower "Lc", reveals a tougher interphase improving the stress transferring. [ABSTRACT FROM AUTHOR]

Most of the therapeutic systems developed for managing chronic skin wounds lack adequate mechanical and hydration properties, primarily because they rely on a single component. This study addresses this issue by combining organic and inorganic materials to obtain hybrid films with enhanced mechanical behavior, adhesion, and fluid absorption properties. To that aim, chitosan/hydrolyzed collagen blends were mixed with halloysite/antimicrobial nanohybrids at 10% and 20% (w/w) using glycerin or glycerin/polyethylene glycol-1500 as plasticizers. The films were characterized through the use of Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and electron microscopy. The mechanical properties were evaluated macroscopically using tensile tests, and at a nanoscale through atomic force microscopy (AFM) and nanoindentation. Thermodynamic studies were conducted to assess their hydrophilic or hydrophobic character. Additionally, in vitro cytocompatibility tests were performed on human keratinocytes. Results from FTIR, TGA, AFM and electron microscopy confirmed the hybrid nature of the films. Both tensile tests and nanomechanical measurements postulated that the nanohybrids improved the films' toughness and adhesion and optimized the nanoindentation properties. All nanohybrid-loaded films were hydrophilic and non-cytotoxic, showcasing their potential for skin wound applications given their enhanced performance at the macro- and nanoscale. [ABSTRACT FROM AUTHOR]

In this study, PMMA/Bentonite and PMMA/HNT nanocomposites were synthesized by in-situ and solution blending methods by using polymethyl methacrylate (PMMA) obtained from methyl methacrylate by emulsion polymerization method and bentonite and halloysite (HNT) at different ratios (5 wt.% and 10 wt.%). Biodegradable PMMA/PLA, PMMA/PLA/Bentonite, and PMMA/PLA/HNT were obtained by mixing the synthesized PMMA and PMMA/clay nanocomposites with a polylactic acid (PLA) with PMMA:PLA weight ratio of 50:50. Characterization studies of synthesized nanocomposites; Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and Scanning Electron Microscope (SEM) analyzes, and Shore-D hardness test was performed. In addition, to observe the effects of clay additives and production methods on biodegradability, the synthesized samples were buried in two different soils, humus soil and cactus soil, and monitored for six months. When the obtained nanocomposites were compared with the pure polymer, it was determined that the hardness values of the nanocomposites were much higher than the pure polymer, and their thermal stability increased with HNT and bentonite additives. When nanocomposites synthesized by the in-situ production method and solution blending production method are compared, it was determined that nanocomposites produced by the solution blending method degrade faster in the soil and show better distribution in the structure. In addition, it was observed that cactus soil created a better degradation environment than humus soil, and bentonite accelerated degradation more than HNT. [ABSTRACT FROM AUTHOR]

AbstractIn this study, CuO@HNTs-SO3H was investigated as a novel eco-friendly heterogeneous solid acid catalyst prepared by straightforward co-precipitation method. Thus, the cost-effective CuO NPs was used to modify halloysite nanotubes initially, which were subsequently further functionalized with sulfonic acid. The prepared catalyst was analyzed by means of FT-IR, XRD, EDX, SEM and TGA methods. Its catalytic activity is investigated in the solvent-free one-pot condensation of various aromatic aldehydes, dimedone, and β-naphthol to produce tetrahydrobenzo[a]xanthen-11-one derivatives. A few benefits of the discovered method are its simple process, quick reaction time, high yields (96%), affordable cost, and the catalyst ability to be reused without losing its activity. [ABSTRACT FROM AUTHOR]

Arsenic contamination in aqueous media is a serious environmental problem, especially in developing countries. In this research, the Box-Behnken response surface methodology was used to optimize the most relevant variables affecting arsenic adsorption on the ZnO-halloysite surface, including temperature, adsorbent dosage, pH, contact time, and As (III) initial concentration. The regression analysis indicated that the experimental data were appropriately fitted to a quadratic model with the adjusted R-squared value (R2) of 0.982 for As(III) adsorption capacity and a linear model with R2 of 0.931 for As(III) removal. The p-values for both adsorption capacity and removal efficiency were below 0.05, with F-values of 116.91 and 115.58, respectively, supporting the model's validity. The optimum conditions for maximum removal of As(III) were determined through numerical and graphical optimization using the desirability function. It was found that the optimum conditions for adsorption were pH = 7.99, contact time of 3.99 h, As(III) initial concentration of 49.96 mg/L, and adsorbent dosage of 0.135 g/40 ml. The accuracy of the optimization procedure was confirmed by a confirmatory experiment, which showed a maximum arsenic removal of 91.31% and an adsorption capacity of 12.63 mg/g under optimized conditions. Moreover, XPS analysis was performed at different pH levels to investigate the As (III) adsorption mechanism. The results demonstrated that As(III) adsorption occurs at acidic and neutral pH levels. On the other hand, when pH is increased to 8, As (III) oxidizes to As (V), and then adsorption occurs. [ABSTRACT FROM AUTHOR]

Innovative cobalt and nickel catalytic materials containing metal nanoparticles immobilized into the inner tubes of pristine halloysite, a naturally occurring nanoclay, and their application in hydrogenation reactions of a large variety of substrates from biomass and industrial wastes are described herein. The catalytic materials with a high metal loading (>24 wt %) were prepared by a one-pot two-step procedure in the absence of additional stabilizers, leading to metal nanoparticles essentially confined into the support lumen (constituted of aggregates of small nanoparticles) as a result of the privileged electrostatic interactions between aluminols and metal acetate salts [Ni-(OAc)2 and Co-(OAc)2]. Both catalytic materials, Ni/Hal and Co/Hal, gave different chemoselectivities toward the reduction of unsaturated functional groups (carbonyl, CC, and nitrile) under solvent-free conditions, thus affording selectively value-added compounds depending on the nature of the metal. In particular, the squalene hydrogenation monitoring permitted identification of the partial hydrogenated products and estimation of the partial turnover numbers and frequencies, achieving a cumulative TON of 110 and TOF of 151 h–1 using the most active catalytic system, i.e., Ni/Hal. [ABSTRACT FROM AUTHOR]

A two-step methodology has been developed utilizing the models of Paul and Takayanagi to determine the modulus of polymer halloysite nanotube (HNT) products. Initially, HNTs and the adjacent interphase are considered as pseudoparticles, and their modulus is evaluated using the Paul model. Subsequently, the modulus of a nanocomposite, consisting of a polymer medium and pseudoparticles, is predicted by Takayanagi equation. The impacts of various factors on the modulus of the products are analyzed, and the results from the two-step method are compared with experimental data from different samples. It has been observed that the modulus of samples progressively increases with an increase in interphase depth. Also, a higher interphase modulus contributes to an enhanced modulus of samples. Nevertheless, excessively high interphase moduli (Ei > 60 GPa) result in only a marginal improvement in the modulus of nanocomposites. Additionally, narrower HNTs are advantageous for producing stronger samples, though the modulus of the nanocomposites slightly diminishes at very high HNT radii (R > 55 nm). The outputs of two-step method agree with the experimental moduli of various HNT-filled systems. [ABSTRACT FROM AUTHOR]

Using halloysite clay and vitamin B1 hydrochloride, a novel acidic halloysite-dendrimer catalytic composite has been developed for conversion of fructose to 5-hydroxymthylfurfural. To grow the dendritic moiety on halloysite, it was first functionalized and then reacted with melamine, epichlorohydrin and vitamin B1 hydrochloride respectively. Then, the resulting composite was treated with ZnCl2 to furnish Lewis acid sites. Use of vitamin B1 as the cationic moiety of ionic liquid obviated use of toxic chemicals and resulted in more environmentally friendly composite. Similarly, dendritic moiety of generation 2 was also grafted on halloysite and the activity of both catalysts for conversion of fructose to 5-hydroxymthylfurfural was investigated to disclose the role of dendrimer generation. For the best catalytic composite, the reaction variables were optimized via RSM and it was revealed that use of 0.035 g catalyst per 0.1 g fructose at 95 °C furnished HMF in 96% yield in 105 min. Turnover numbers (TONs) and frequencies (TOFs) were estimated to be 10,130 and 5788 h−1, respectively. Kinetic studies also underlined that Ea was 22.85 kJ/mol. The thermodynamic parameters of Δ H ≠ , Δ S ≠ and Δ G ≠ , were calculated to be 23 kJ/mol, − 129.2 J/mol and 72.14 kJ/mol, respectively. Notably, the catalyst exhibited good recyclability and hot filtration approved heterogeneous nature of catalysis. [ABSTRACT FROM AUTHOR]

NiO nanoparticles were assembled on the surface of Halloysite nanotubes, which were subsequently further functionalized by sulfonic acid, to create NiO@HNTs-SO3H composite. This composite is employed as a heterogeneous catalyst in the one-pot synthesis of 1-(benzothiazolylamino) methyl-2-naphthols starting from aryl aldehyde, β-naphthol and 2-aminobenzothiazole as well as Tetrahydrobenzo[b]pyrans starting from aldehyde, dimedone and malononitrile. The catalyst was examined using Fourier transform infrared (FT-IR), energy dispersive X-ray (EDX), X-ray diffraction (XRD) pattern, and scanning electron microscopy (SEM) images. The synthesized organic compounds were examined using 1H NMR and 13C NMR spectroscopy and mass analysis by HRMS. The most notable benefits of the current work are its straightforward setup, gentle reaction conditions, green solvents, excellent yields, ease of purification, high efficiency, and the use of a recoverable and environmentally friendly catalyst. The easy separation and reusability of NiO@HNTs-SO3H catalyst after five runs confirmed the stability and effectiveness of the catalyst. [ABSTRACT FROM AUTHOR]

This study is focused on the preparation of active packaging based on sodium caseinate (SC) and Rosa damascena essential oil (REO) reinforced by halloysite (Hal, 1 and 3 wt%) and bacterial cellulose (BC, 2 wt%). Based on FE-SEM images, the simultaneous incorporation of Hal and BC (BC2H3) could decrease a porosity of SC film and generate a homogenous surface, ascertaining well dispersion of reinforcements through the protein matrix. The porosity and non-homogeneity of the REO-loaded composites decreased in comparison with unloaded films due to the establishment of hydrogen bonding interactions. EDX mapping of Al and Si atoms proved the well distribution of halloysite into the SC film. While for REO-loaded nanocomposites, the aggregated regions enhanced by increasing the Hal content. XRD patterns of REO-bearing nanocomposites showed that the intensities of reflections belonging to Hal and BC decreased, indicating their increased amorphous structure. TG analysis indicated the improved thermal resistance of Hal-reinforced nanocomposites in comparison with the SC film. The thermal stability of nanocomposites showed insignificant change after addition of REO due to the presence of halloysite which could retard or delay the escape of EO molecules. Hal exhibited a more significant influence on tensile strength (TS) of the film as compared to BC. BC exhibited a more significant influence on barrier properties. The simultaneous incorporation of BC and Hal could compensate the decreased TS of REO-loaded films. The inclusion of REO into nanocomposites amplified their barrier and antibacterial properties. BC2H3/EO and BC2H1/EO nanocomposites satisfied the criteria of an ideal food packaging. [ABSTRACT FROM AUTHOR]

The synthesis of a nanocomposite material consisting of Cu nanoparticles encapsulated in halloysite nanotubes (Cu@Hal) was achieved by the reduction of Cu(NO3)2 ⋅ 3H2O with sodium ascorbate/sodium borohydride in an aqueous suspension of trisodium citrate and halloysite. The nanocomposite was found to be an effective heterogeneous catalyst for the multicomponent copper catalyzed azide‐alkyne cycloaddition reaction (CuAAC). A variety of terminal alkynes reacted with benzyl halides and sodium azide in the presence of Cu@Hal in water. In situ formation of the organic azides afforded the corresponding 1,4‐disubstituted 1,2,3‐triazoles regioselectivily, in excellent yields. The catalyst was easily recovered and recycled without loss of activity with low metal leaching. [ABSTRACT FROM AUTHOR]

Membrane technology is known as one of the most efficient and extensive methods for oily wastewater treatment. In this research, polyvinyl chloride (PVC)-based mixed matrix membranes containing Uio66-NH2 nanoparticles and modified halloysite nanotubes (HNTs) were prepared using the phase inversion method. The synthesized membranes were characterized by field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) and contact angle measurement analysis. Then, the effect of these nanoparticles was investigated for oil/water emulsion separation in the ultrafiltration process. To evaluate the prepared membranes, pure water flux, mean pore size, and oil separation ultrafiltration tests were performed. The results exhibited that addition of HNTs to the casting solution enhanced the pure water flux about up to 4 folds. Overall experimental results showed that due to the uniform distribution of halloysite nanotubes in sample 2, water contact angle decreased from 81° to 72°. UF results confirmed that sample 2 had the potential of rejecting 97% of sunflower oil. [ABSTRACT FROM AUTHOR]

Polyelectrolytes with strong acidic functionality are among the prime sources for water desalination techniques. Poly 2‐acrylamido‐2‐methylpropanesulfonic acid (PAMPS) is one such polymer showing polyelectrolyte characteristics because of highly acidic SO3H group (pKa < 2) and film‐forming characteristics of flexible polymeric chains. Halloysite nanotubes functionalized with polyelectrolytes can be considered for water purification, as halloysite was reported to be efficient in removing dissolved metal salts. These polyelectrolytes can be introduced as a blend with other components, or they can be synthesized via in situ to form flexible membranes. Polymer nano‐filtration membranes with controlled crosslinking were designed as a function of halloysite and AMPS composition using in situ free radical polymerization with other polymers such as polyvinylidene fluoride and polyvinylpyrrolidone to strengthen the polymer matrix. The synthesized membranes were characterized using FTIR, SEM, EDS, TGA, and DTG techniques. Equilibrium water content, contact angle, water flux, salt rejection efficiency, and antifouling studies are also carried out for these membranes in water purification. [ABSTRACT FROM AUTHOR]

The removal of dyes from effluents of textile industries represents a technological challenge, due to their significant environmental impact. The application of halloysite (Hal) and palygorskite (Pal) clay minerals as adsorbents for the removal of Congo red (CR) and methylene blue (MB) was evaluated in this work. The materials were applied both in natural and acid-treated forms, and characterized by XRD, XPS, SEM–EDS, FTIR, and N2 adsorption–desorption isotherm techniques to identify their properties and main active sites. The adsorbents showed potential to remove CR (> 98%) and MB (> 85%) within 180 min, using 0.3 g adsorbent and initial dye concentration of 250 mg L−1. Semi-empirical quantum mechanical calculations (SQM) confirmed the interaction mechanism between dyes and the adsorbents via chemisorption (− 69.0 kcal mol−1 < Eads < − 28.8 kcal mol−1), which was further observed experimentally due to the high fit of adsorption data to pseudo-second order kinetic model (R2 > 0.99) and Langmuir isotherm (R2 > 0.98). The use of Pal and Hal to remove dyes was proven to be economically and environmentally viable for industrial application. [ABSTRACT FROM AUTHOR]

Abstract Using halloysite clay and vitamin B1 hydrochloride, a novel acidic halloysite-dendrimer catalytic composite has been developed for conversion of fructose to 5-hydroxymthylfurfural. To grow the dendritic moiety on halloysite, it was first functionalized and then reacted with melamine, epichlorohydrin and vitamin B1 hydrochloride respectively. Then, the resulting composite was treated with ZnCl2 to furnish Lewis acid sites. Use of vitamin B1 as the cationic moiety of ionic liquid obviated use of toxic chemicals and resulted in more environmentally friendly composite. Similarly, dendritic moiety of generation 2 was also grafted on halloysite and the activity of both catalysts for conversion of fructose to 5-hydroxymthylfurfural was investigated to disclose the role of dendrimer generation. For the best catalytic composite, the reaction variables were optimized via RSM and it was revealed that use of 0.035 g catalyst per 0.1 g fructose at 95 °C furnished HMF in 96% yield in 105 min. Turnover numbers (TONs) and frequencies (TOFs) were estimated to be 10,130 and 5788 h−1, respectively. Kinetic studies also underlined that Ea was 22.85 kJ/mol. The thermodynamic parameters of $$\Delta {\text{H}}^{ \ne }$$ Δ H ≠ , $$\Delta {\text{S}}^{ \ne }$$ Δ S ≠ and $$\Delta {\text{G}}^{ \ne }$$ Δ G ≠ , were calculated to be 23 kJ/mol, − 129.2 J/mol and 72.14 kJ/mol, respectively. Notably, the catalyst exhibited good recyclability and hot filtration approved heterogeneous nature of catalysis.

Abstract Background Polymethylmethacrylate (PMMA) bone cement is used in orthopedics and dentistry to get primary fixation to bone but doesn’t provide a mechanically and biologically stable bone interface. Therefore, there was a great demand to improve the properties of the PMMA bone cement to reduce its clinical usage limitations and enhance its success rate. Recent studies demonstrated that the addition of halloysite nanotubes (HNTs) to a polymeric-based material can improve its mechanical and thermal characteristics. Objectives The purpose of the study is to assess the compressive strength, flexural strength, maximum temperature, and setting time of traditional PMMA bone cements that have been manually blended with 7 wt% HNT fillers. Methods PMMA powder and monomer liquid were combined to create the control group, the reinforced group was made by mixing the PMMA powder with 7 wt% HNT fillers before liquid mixing. Chemical characterization of the HNT fillers was employed by X-ray fluorescence (XRF). The morphological examination of the cements was done using a scanning electron microscope (SEM). Analytical measurements were made for the compressive strength, flexural strength, maximum temperature, and setting time. Utilizing independent sample t-tests, the data was statistically assessed to compare mean values (p

Highlights In the current study, thermoset nanocomposites including halloysite nanotubes (HNTs) have been prepared through thiol‐epoxy click reaction at ambient conditions. Naturally available HNTs are first modified separately by epoxy and thiol groups and used as nanofillers in a mixture of trimethylolpropane triglycidyl ether and trimethylolpropane tris(3‐mercaptopropionate) ranging from 0 to 5 wt%. Fourier transformed infrared (FT‐IR) spectroscopy has been used to observe the characteristic bands of the pure and modified halloysite, neat thermoset, and HNT/thermoset nanocomposites. Thermal properties of epoxide‐modified and thiol‐modified halloysite nanotubes and also final thermoset nanocomposites have been investigated using thermogravimetric analysis (TGA) by comparing pure halloysite and neat thermoset, respectively. The dispersion of HNT nanotubes in thermoset matrix has been examined with scanning electron microscopy (SEM). In addition to the agglomerated/non‐agglomerated distribution, the present of HNT has been proved by EDX. The effect of HNT‐Epoxide and HNT‐Thiol loadings on mechanical properties has been examined by tensile test. All nanocomposites were found to exhibit better tensile strength than that of neat thermoset, called as reference sample. The most enhanced mechanical properties have been detected in the nanocomposite with 3% modified‐HNTs by weight because of the best dispersion, which promotes effective interactions between the nanotubes and thermoset matrix. Tensile strength of thermoset nanocomposites increased by 43% and 62%, while elongation at break increased by 58% and 149% when 3 wt% HNT‐Epoxide and 3 wt% HNT‐Thiol were added to the matrix, respectively. Further increase of HNT added to the matrix causes agglomeration of nanotubes and thus deterioration of mechanical properties. Pure HNT was modified and successfully converted into HNT‐Epoxide and HNT‐Thiol. In‐situ preparation of thermoset nanocomposites with modified‐HNTs was effectively achieved via thiol‐epoxy click chemistry. Mechanical properties increased significantly with both HNT‐Epoxide and HNT‐Thiol loading ratio up to 3 wt%. The presence and agglomerated/non‐agglomerated dispersion of modified‐HNTs in the thermoset matrix were verified by SEM–EDX analysis. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of halloysite nanotube (HNT) content on mechanical and shape memory properties of additively manufactured polyurethane (PU)/HNT nanocomposites. The inclusion of 8 wt% HNTs increases their tensile strength by 30.4% when compared with that of virgin PU at 44.75 MPa. Furthermore, consistently significant increases in tensile modulus, compressive strength and modulus, as well as specific energy absorption are also manifested by 47.2%, 34.0%, 125% and 72.7% relative to neat PU at 2.29 GPa, 3.88 MPa, 0.28 GPa and 0.44 kJ/kg respectively. However, increasing HNT content reduces lateral strain due to the restricted mobility of polymeric chains, leading to a decrease in negative Poisson's ratio (NPR). As such, shape recovery ratio and time of PU/HNT nanocomposites are reduced by 9 and 45% with the inclusion of 10 wt% HNTs despite an increasing shape fixity ratio up to 12% relative to those of neat PU. [ABSTRACT FROM AUTHOR]

The reaction steps involved in the 5‐hydroxymethylfurfural to 2,5‐furandicarboxylic acid conversion by means of H2O2 were investigated employing a dedicated computational protocol based on density functional theory. The catalytic environment of choice was a molecular model representing a portion of the halloysite nanotube outer surface, functionalized by an organosilane, the 3‐aminopropyltriethoxysilane, whose amino group bonds one gold atom. At this stage of the investigation, the process was fully detailed in terms of the interactions between the reaction intermediates and the catalyst, and the reaction standard free energies. In addition, the energy barriers of the elementary steps involving the hydrogen migration from the adsorbed organic species to the gold atom were analyzed. On the basis of the interaction geometries, a certain distinction among the preferred reaction path can be inferred as a function of the net negative charge characterizing the catalyst outer surface. Since the inner surface of halloysite can represent the acid environment needed to obtain 5‐hydroxymethylfurfural through dehydration of fructose, the present study is framed in a wider research field where the possibility to consider functionalized halloysite as one‐pot reactor for the valorization of biomass is explored. [ABSTRACT FROM AUTHOR]

Molecules confined within nanometer‐scale environments frequently exhibit a distinct physical response in contrast to those found in bulk conditions. In this study, intercalates of lauric acid (LA) are synthesized within halloysite nanotubes (HNT), successfully trapping 12 wt.% of LA within the internal HNT tube, as demonstrated by transmission electron microscopy (TEM), and wide‐angle and small‐angle X‐ray scattering (WAXS/SAXS) techniques. Furthermore, it is noted that the confinement of LA within the HNT lumen resulted in a significant reduction in LA crystallinity, consistent with the impact of geometric constraints on crystallization behavior. The presence of a significant amorphous phase in the intercalates proved beneficial for the gradual release of LA into water, as evidenced by pH changes. Remarkably, the necessity of employing a vacuum method and extended contact time (72 h) for the physical entrapment of LA in ethanol within the HNT lumen is found to be unnecessary, as similar physical characteristics are observed in an intercalate generated without vacuum and with very short contact time (<1 h). Finally, it is observed that the source of HNT is crucial in determining the final properties of the confined material. [ABSTRACT FROM AUTHOR]

Metalized plastic current collectors (MPCCs) have shown potential in improving the energy density and safety of lithium‐ion batteries (LIBs). However, the poor mechanical strength, weak interfacial adhesion force, and surface metal corrosion have impeded the practical application of MPCCs. Here, an innovative engineering of MPCCs is proposed by incorporating halloysite nanotubes (HNTs) as fillers into polyimide (PI) polymer layer, which is further coated with two thin copper (Cu) layers. Because of the strong bonding between HNTs surface and the PI precursor, HNTs improve the mechanical strength of PI‐HNTs composite film, reinforce the interfacial adhesion force between the PI‐HNTs film and the coated Cu layer, and suppress the Cu corrosion by electrolyte. The prepared MPCCs exhibit a low mass density and only account about one‐fifth of the density of commercial Cu CCs. Furthermore, the PI‐HNTs‐Cu composite demonstrates significantly enhanced interfacial adhesion force doubled to 4 N cm−1 along with prolonged stability under electrolyte immersion and electrochemical reaction conditions, and delivers a high fracture strength of 125 MPa. LIBs assembled with MPCCs deliver a twice higher discharge capacity compared to battery with Cu CCs and reach a long‐term cycle capacity retention as high as 92.9% at 0.5 C after 500 cycles. [ABSTRACT FROM AUTHOR]

Currently, there are few reports of core–shell‐structured smoke suppressants that can provide a growth substrate and stabilize the char layer. In response to this problem, core–shell nanoparticles of halloysite nanotubes (HNTs) coated with copper itaconate complex were prepared by layer‐by‐layer assembly method. The electrostatic forces between HNTs and copper ions and the coordination between the itaconic acid and copper ions contributed this synthesis. The micromorphology, chemical composition, and structure of HNT@CuC5H4O4 were characterized, and its effects on the flame‐retardant and smoke‐inhibition properties, mechanical properties, and thermal stability of the soft polyvinyl chloride (PVC) were investigated. The results showed that the core–shell structure of HNT@CuC5H4O4 contributed to its homogeneous dispersion in PVC and the formation of interlocking mesh structure. Thus, the incorporation of HNT@CuC5H4O4 enhanced the strength and stiffness of soft PVC without sacrificing its ductility. Besides, copper ions on HNT@CuC5H4O4 could promote the cross‐linking carbonization of the PVC at high temperature. The formed char layer catalyzed by CuC5H4O4, together with its attached three‐dimensional network structure of HNT constituted a compact and continuous char layer with high thermal stability, which effectively prevented the release of combustible volatiles and toxic gases as well as heat transfer. [ABSTRACT FROM AUTHOR]

The goal of this work is to investigate the mechanical and fracture characteristics of polylactic acid (PLA)/thermoplastic polyurethane (TPU)/halloysite (HNT). HNT with three levels (0, 3, and 6 wt.%) and TPU with three levels (10, 20, and 30 wt.%) were used as variables. The investigation of tensile properties revealed contrasting effects of TPU and HNT levels. Increasing TPU content to 30 wt.% led to a decrease in strength and modulus by 36% and 42% in turn, however resulted in a remarkable 338% improvement in elongation at break. Conversely, the addition of 3 wt.% HNT enhanced both tensile strength and modulus, although it caused a reduction in elongation at break. The results concerning fracture properties showed by incorporating TPU up to 30 wt.% EWF (w e ) and non-EWF (βw p ) rose by 459% and 178%, respectively. Additionally, the inclusion of 3 wt.% HNT further elevated the EWF compared to the compound containing 10 wt.% TPU without HNT. Through optimization, the compound with 10 wt.% TPU and 3 wt.% HNT was shown to have the optimum strength, stiffness, and toughness balance. [ABSTRACT FROM AUTHOR]

Background: Polymethylmethacrylate (PMMA) bone cement is used in orthopedics and dentistry to get primary fixation to bone but doesn't provide a mechanically and biologically stable bone interface. Therefore, there was a great demand to improve the properties of the PMMA bone cement to reduce its clinical usage limitations and enhance its success rate. Recent studies demonstrated that the addition of halloysite nanotubes (HNTs) to a polymeric-based material can improve its mechanical and thermal characteristics. Objectives: The purpose of the study is to assess the compressive strength, flexural strength, maximum temperature, and setting time of traditional PMMA bone cements that have been manually blended with 7 wt% HNT fillers. Methods: PMMA powder and monomer liquid were combined to create the control group, the reinforced group was made by mixing the PMMA powder with 7 wt% HNT fillers before liquid mixing. Chemical characterization of the HNT fillers was employed by X-ray fluorescence (XRF). The morphological examination of the cements was done using a scanning electron microscope (SEM). Analytical measurements were made for the compressive strength, flexural strength, maximum temperature, and setting time. Utilizing independent sample t-tests, the data was statistically assessed to compare mean values (p < 0.05). Results: The findings demonstrated that the novel reinforced PMMA-based bone cement with 7 wt% HNT fillers showed higher mean compressive strength values (93 MPa) and higher flexural strength (72 MPa). and lower maximum temperature values (34.8 °C) than the conventional PMMA bone cement control group, which was (76 MPa), (51 MPa), and (40 °C), respectively (P < 0.05). While there was no significant difference in the setting time between the control and the modified groups. Conclusion: The novel PMMA-based bone cement with the addition of 7 wt% HNTs can effectively be used in orthopedic and dental applications, as they have the potential to enhance the compressive and flexural strength and reduce the maximum temperatures. [ABSTRACT FROM AUTHOR]

In this article, the suitability of utilization of porous lumen structure of Halloysite (Hal) nanoclay has been studied elaborately. To utilize the lumen structure for membrane development, the effect of temperature, pressure and time on the porous lumen feature and subsequent use of the clay in pristine form as a membrane coating material for separation purposes at specified temperatures shows the importance of this study. The present study investigates structural changes in Halloysite nanoclay's inherent porous tubular morphology. Membranes are prepared by coating clay-alumina porous support tube with Halloysite sol under pressure and temperature of 100 and 160 °C for 24, 48 and 64 h, respectively. XRD and FTIR reveal that the tubular structure remains intact under experimental conditions. In contrast, the morphology of pristine Hal powder treated at the specified temperature and under in situ developed autogenous pressure shows a significant textural change in the nanotubular morphology observed from FESEM. At 100 °C, lumen porosity remains intact, but at 160 °C, under higher pressure, lumen mouth sealing, conjoining and coalescence of the halloysite nanotubes (HNT) result. In addition, for both temperatures under existing operating pressure, the effect of 24 h time duration on morphology is less. For practical viability, a preliminary study for dye removal is carried out with H1 membrane coating, which shows promising %rejection values. This study on powders and membrane coatings might thus help to assign new application fields, such as membrane-based separation utilizing the porous nature of HNT by controlling different process parameters. [ABSTRACT FROM AUTHOR]

This paper presents the results of borehole investigations and laboratory tests carried out to characterize the soils derived from in situ weathering of tuff in Central Java, Indonesia. The 70 m thick weathering profile of the Quaternary tuff consisted of residual soil and completely to highly decomposed rocks. The relatively low dry unit weight and cohesion but high water content, porosity, plastic and liquid limits, and angle of internal friction of the soils in the present study were related to the dominance of halloysite clay minerals. The established relationships to predict soil shear strength parameters from the soil plasticity index and standard penetration test (SPT) N-values were examined, and linear and non-linear relationships for soils derived from in situ weathering of tuff were proposed. [ABSTRACT FROM AUTHOR]

One solution to comply with the strict regulations of the European Commission and reduce the environmental footprint of composites is the use of composite materials based on bio-polymers and fillers from natural resources. The aim of our work was to obtain and analyze the properties of bio-polymer nanocomposites based on bio-PA (PA) and feather keratin–halloysite nanohybrid. Keratin (KC) was mixed with halloysite (H) as such or with the treated surface under dynamic conditions, resulting in two nanohybrids: KCHM and KCHE. The homogenization of PA with the two nanohybrids was conducted using the extrusion processing process. Two types of nanocomposites, PA–KCHM and PA–KCHE, with 5 wt.% KC and 1 wt.% H were obtained. The properties were analyzed using SEM, XRD, FTIR, RAMAN, TGA, DSC, tensile/impact tests, DMA, and nanomechanical tests. The best results were obtained for PA–KCHE due to the stronger interaction between the components and the uniform dispersion of the nanohybrid in the PA matrix. Improvements in the modulus of elasticity and of the surface hardness by approx. 75% and 30%, respectively, and the resistance to scratch were obtained. These results are promising and constitute a possible alternative to synthetic polymer composites for the automotive industry. [ABSTRACT FROM AUTHOR]

Polybutylene terephthalate (PBT) nanocomposites were melt-blended with two types of Turkish halloysite nanotubes (HN). Naturally occurring HN samples were used to produce PBT-based composites at the HN compositions of 1%, 3%, 5%, and 10%. Findings of neat and silane-coated HN-containing composite samples were compared to investigate the interfacial adhesion between polymer matrix and reinforcement material. According to test results, a 1% amount of HN was found to be the most suitable option in the case of mechanical and thermal properties of composites. Additionally, silane-modified grade displayed highly indicative improvements compared to pristine HN clay due to better interfacial adhesion of halloysite nanotubes to the PBT matrix was accomplished. Property enhancements achieved for composite samples containing low contents of HN were confirmed by morphological examinations. As a result, the PBT/ 1% HN-S composite sample was bookmarked as the most suitable option to fabricate HN-reinforced PBT-based nanocomposites in terms of mechanical, thermo-mechanical, morphological, thermal, and physical performances based on the findings in this study. Silane-modified halloysite grades exhibited better results, and they were found to be more suitable in the case of applications of PBT. [ABSTRACT FROM AUTHOR]

With the ever‐increasing need for energy storage devices with high energy density, lithium (Li) metal anodes have been revisited. Due to the high reactivity of Li metal and the safety issues associated with liquid electrolytes, solid polymer electrolytes (SPEs) have gain attention. Polyethylene oxide (PEO) with the highest ionic conductivity (σ) among the polymers faces serious problems. The inability to meet the practical limit of σ due to its high crystallinity, and its low thermomechanical stability above its melting temperature, have limited its large‐scale application. In this research, anionic polyurethane dispersion (PUD) based on poly (ε‐caprolactone) (PCL) was synthesized and different PUD:PEO compositions was prepared using water as a solvent. Halloysite nanotube (HNT) was also used to improve the ionic conductivity by providing a new pathway for conducting lithium ions in the composition. The results corroborated that the presence of PUD stabilized the storage modulus of the host polymer above Tm of PEO. The ionic nature of the selected PUDs resulted in a transference number of 0.59 and the presence of HNT increased this value to 0.72. The presence of HNTs also led to a significant increase in σ by about three times compared to the control sample. [ABSTRACT FROM AUTHOR]

A series of halloysite nanotube‐silica (HNTs‐SiO2) nanocomposite fillers were prepared by in‐situ assembly, and a reinforced SiO2/SR composite was obtained by filling them into silicone rubber (SR). The morphology and structural characterization of HNTs‐SiO2 and HNTs‐SiO2/SR and the properties of the HNTs‐SiO2/SR were studied. As a result, the small particle size SiO2 was firmly anchored onto the HNTs surface, and the obtained HNTs‐SiO2 nanofillers were uniformly dispersed in SR. At a 30 phr fixed filler loading, the weakest filler network and the best filler dispersion were obtained when HNTs content in HNTs‐SiO2 was 5%. This resulted in a maximum tensile strength obtained of 6.2 MPa, 1.55 times that of SiO2/SR with the same filler loading, and a maximum elongation at break of 418%, 1.67 times that of the SiO2/SR with the same filler loading, and at the same time the tearing strength and hardness are also improved. Furthermore, the silicone rubber also showed improved thermal stability, with an initial degradation temperature increase of 30°C under a nitrogen atmosphere. Highlights: HNTs–SiO2 nanocomposites were successfully prepared by the self‐assembly method and used as fillers in SR as a new type of reinforcing material.The 1D HNTs act as a barrier to prevent SiO2 aggregation and improved fillers dispersion.The elongation at break and tensile strength of 5% HNTs‐SiO2/SR are 67% and 55% higher than those of SiO2/SR, respectively.The silicone rubber also showed improved thermal stability. [ABSTRACT FROM AUTHOR]

In situ formation of carbon dots on halloysite nanotubes is demonstrated by treating polyacrylamide-grafted halloysite nanotubes with polycarboxylic acid without the recourse to extremely high temperatures or solvents. Thermosensitive luminescence and phosphorescence properties are carefully investigated. The polyacrylamide-grafted halloysite nanotubes are further processed as composite films for encryptable thermal printing. [ABSTRACT FROM AUTHOR]

Chemical modification of the surface of halloysite nanotubes (HNT) by alkalization (with sodium hydroxide (NaOH)) and grafting with silanes (bis(trimethylsilyl)amine (HMDS)) was carried out. The efficiency of the alkalization and grafting process was evaluated by X–ray diffraction (XRD), Fourier–transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and the nitrogen adsorption method were used. XRD and FTIR analysis confirmed the formation of bonds of trimethylsilyl groups to the HNT surface which changed the nature of the surface from hydrophilic to hydrophobic. In addition, it was noted that grafting with silanes decreases by 7.2% the specific surface area of the halloysite compared to the alkalized material. High–density polyethylene (HDPE) composites with halloysite (HNT), alkalized halloysite (alk–HNT), and HMDS–modified halloysite (m–HNT) were processed in the molten state in a Brabender mixer chamber. On SEM/EDS micrographs of HDPE composites with silanized HNT, a change in surface characteristics from smooth to ductile was observed. Higher melting point values based on differential scanning calorimetry (DSC) analysis of HDPE composites with 5%wt silanized halloysite in comparison with HNT and alk–HNT of, respectively, 2.2% and 1.4% were found, which indicates a slight beneficial influence of the filler on the quality of ordering of the crystalline phase of the matrix. [ABSTRACT FROM AUTHOR]

The adsorption of copper ions and Reactive Red 120 azo dye (RR-120) as models of water pollutants on unmodified halloysite (H-NM), as well as halloysites modified with sulfuric acid (H-SA) and (3-aminopropyl) triethoxysilane (H-APTES), was investigated. The results showed that adsorption of both the adsorbates was pH-dependent and increased with the increase in halloysite dosage. The adsorption kinetics were evaluated and the results demonstrated that the adsorption followed the pseudo-second-order model. The adsorption isotherms of Cu(II) ions and RR-120 dye on the halloysites were described satisfactorily by the Langmuir model. The maximum adsorption capacities for the Cu(II) ions were 0.169, 0.236, and 0.507 mmol/g, respectively, for H-NM, H-SA, and H-APTES indicating that the NH2-functionalization rather than the surface area of the adsorbents was responsible for the enhanced adsorption. The adsorption capacities for RR-120 dye were found to be 9.64 μmol/g for H-NM, 75.76 μmol/g for H-SA, and 29.33 μmol/g for H-APTES. The results demonstrated that APTES-functionalization and sulfuric acid activation are promising modifications, and both modified halloysites have good application potential for heavy metals as well as for azo dye removal. [ABSTRACT FROM AUTHOR]

Recent research is shifting towards adopting recyclable and sustainable plastics instead of traditionally used thermosetting materials. Accordingly, vitrimers behave both as thermoplastics as well as thermosetting polymers. Inimitable vitrimer polymers have been developed with dynamically crosslinked structures enhancing the durability, reprocessing, and mechanical and chemical stability features. This state-of-the-art review discusses vitrimer nanocomposites reinforced with carbonaceous (carbon nanotube, graphene, and graphene oxide) and inorganic (silica, halloysite nanotube) nanofillers has been particularly emphasized. Beneficial structural, microstructural, mechanical strength, modulus, thermal, conducting, reprocessing, engineering, shape memory, self-healing, kinetic, and theoretical topographies have been observed with vitrimers or modified vitrimers (disulfide or ether functional) matrices along with nano-reinforcements towards multifunctional architectures. High-tech vitrimeric nanocomposites show potential regarding electromagnetic shielding, anticorrosion coatings, sensors, joints welding, adhesives, and other sectors. Versatile design compensations, degradability, reprocessability, and methodological features/applications point towards next-generation sustainable materials for modern industries. Hence, this article presents advancements in the field of high performance vitrimeric nanocomposites. [ABSTRACT FROM AUTHOR]

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Nanoclays are a class of nanomaterials extensively used to prepare polymer nanocomposites. In this study, four types of common nanoclays were selected to prepare chitosan–polyvinyl alcohol (CP) nanocomposite films. Montmorillonite cloisite Na+ (MMT), organically modified montmorillonite (OMMT), and bentonite (BNT), as layered aluminosilicates, and halloysite nanotubes (HNT), as a tubular nanoclay, were blended with CP films at concentrations of 1.5, 3 and 4.5%. The nanocomposite films were characterized by FTIR, XRD, SEM/EDX, AFM, tensile strength, and antibacterial tests. SEM/EDX results showed a more uniform distribution of the OMMT and HNT nanoclays in the polymer matrix. AFM images showed a rougher surface for nanocomposite films compared to CP film. Increasing the nanoclay concentration in the films from 1.5 to 4.5% resulted in higher tensile strength for HNT and MMT while the trend was reversed for OMMT and BNT. Among the samples, nanocomposite films composed of OMMT and BNT showed the highest tensile strength at the lowest concentrations (CP-OMMT1.5 99 ± 3.7 MPa, CP-B1.5 81 ± 1.5 MPa). The nanocomposite films prepared from OMMT showed the highest antibacterial activity against E. coli and S. aureus with an inhibition zone of 15 and 19 mm, respectively. The results of this study showed that BNT and OMMT are promising nanoclays for enhancing the mechanical properties and antibacterial activity of hydrophilic polymers. The results of this research can provide new insights into selecting suitable nanoclays for different applications. [ABSTRACT FROM AUTHOR]

The effect of the preparation protocol of chitosan (CHI) based films filled with wax microparticles stabilized by halloysite nanotubes (HNTs) in Pickering emulsions (PE) is investigated. The obtained results show that the addition of acetic acid (before or after the preparation of wax/HNT microspheres) affects the properties of the composite films as well as the colloidal stability of PE. The colloidal behavior of CHI/HNT/wax PE by optical microscopy and sedimentation tests are studied. On the other hand, the corresponding composite films (prepared by solvent casting method) are characterized through several techniques, including Scanning Electron Microscopy, UV–vis spectrometer, water permeability, and contact angle measurements. Dynamic Mechanical Analysis allows this to estimate the effect of wax microparticles on the tensile performances of CHI‐based films. As a general consideration, the filling of the CHI matrix with wax/HNT improves the physicochemical properties of the films. Finally, the efficacy of the films as adsorbents of n‐dodecane vapors is explored. Due to the presence of hydrophobic domains (wax embedded in CHI), the composite films possess higher adsorption efficiencies compared to pristine CHI. Accordingly, it can be stated that the combination of CHI with wax/HNT microparticles is promising to obtain biocompatible composite films useful for remediation purposes. [ABSTRACT FROM AUTHOR]

The photosensitive pharmaceutical ingredient moxifloxacin hydrochloride degrades during storage under the influence of external factors, such as elevated temperature and ultraviolet and visible light irradiation, resulting in a decrease in the concentration of the active substance. To increase its resistance to these external factors, moxifloxacin hydrochloride was encapsulated in halloysite nanotubes. The aim of this study was to determine the level of degradation of moxifloxacin hydrochloride in its native and encapsulated states under the influence of temperature and ultraviolet and visible light irradiation. Encapsulation was carried out by the vacuum method and confirmed by TEM microscopy. The residual content of the photosensitive pharmaceutical ingredient after degradation was monitored by high-performance liquid chromatography of a model solution with an initial concentration of 2 mg/ml, prepared from samples of native and encapsulated moxifloxacin hydrochloride previously tested under the influence of temperature and light irradiation. Encapsulated moxifloxacin hydrochloride showed increased resistance to degradation caused by visible light irradiation at 200 watt-hours/m² (by 10.9%); resistance to degradation was increased by 13.4% and 14% under test conditions during 24 hours of ultraviolet light irradiation and thermostating at a temperature of 60°C, respectively, compared to non-encapsulated moxifloxacin hydrochloride. [ABSTRACT FROM AUTHOR]

A hybrid of halloysite nanotubes decorated with titanium dioxide nanoparticles (HNTs@TiO2) was synthesized by the sol–gel method and then mixed with ultra‐high molecular polyethylene (UHMWPE) by melt compounding to enhance its wear resistance properties. The incorporation of HNTs@TiO2 increased the crystallinity as well as the hardness of UHMWPE nanocomposites, which benefited less prone to plastic deformation during the friction process. In addition, the UHMWPE/HNTs@TiO2 maintained a high ductility character with a slight decrease in tensile strength compared to pure UHMWPE. With the addition of 3 wt% HNTs@TiO2, the UHMWPE nanocomposite achieved a remarkably low friction coefficient of 0.073 and a reduced wear rate of 6.67 × 10−6 mm3/N·m. These values represented a 32.4% decrease in friction coefficient and a 43.9% decrease in wear rate compared to pure UHMWPE. The improvement in wear resistance was due to the dislodged TiO2 and HNTs had good synergistic rolling effects at the counterface. Furthermore, the wear scan morphology observation revealed that the transferred HNTs@TiO2‐based materials could help to improve the quality of the tribofilms, which alleviated the abrasive wear from the metallic counterpart. This work offers a feasible way to enhance the wear resistance of UHMWPE nanocomposite without sacrificing the high ductility for expanding its engineering applications. Highlights: TiO2‐decorated halloysite nanotubes were synthesized by the sol–gel method.The addition of HNTs@TiO2 maintained the high ductility character of UHMWPE.The UHMWPE composite with 3 wt% HNTs@TiO2 had the best wear resistance. [ABSTRACT FROM AUTHOR]

Antibiotics have been established to induce indiscriminate detrimental effects on the gut commensal bacteria which are vital for human health. This study unprecedently reports the mitigation of this challenge through the targeted delivery of antibiotics to a specific intestinal model pathogen using naturally occurring nanoclay. The designed Halloysite nanotubes targeting (HaNTr) system employs intrinsically mesoporous clay particles, functionalized with antibodies against Escherichiacoli (E. coli). Loaded with the antibiotic ciprofloxacin (CIP), the HaNTr particles demonstrate enhanced selectivity of their payload in a human microbiome ex vivo system, preserving the composition of non‐target populations. Furthermore, the HaNTr system exhibits up to a 10‐fold increase in selectivity against E. coli, compared to neat CIP, in a heterogenous culture. This enhanced selectivity is attributed to the sustained and localized release of CIP from the HaNTr particles (≈0.8 ng CIP min−1 mg−1), following their specific binding to target bacteria, as quantitatively measured by high‐throughput imaging flow cytometry. Importantly, HaNTr particles are also shown to be biocompatible with Caco‐2 cells, mimicking the intestinal epithelium. This work highlights the prominent capability of the HaNTr system in alleviating antibiotic‐associated dysbiosis by the targeted delivery of antimicrobials to potentially any microorganism against which the immobilized capture probe can be customized. [ABSTRACT FROM AUTHOR]

Despite the mechanical and physical properties of polyurethane foams (PUF), their application is still hindered by high inflammability. The elaboration of effective, low-cost, and environmentally friendly fire retardants remains a pressing issue that must be addressed. This work aims to show the feasibility of the successful application of natural nanomaterials, such as halloysite nanotubes and nanocellulose, as promising additives to the commercial halogen-free, fire-retardant triphenyl phosphate (TPP) to enhance the flame retardance of open-cell polyurethane foams. The nanocomposite foams were synthesized by in situ polymerization. Investigation of the mechanical properties of the nanocomposite PUF revealed that the nanoscale additives led to a notable decrease in the foam's compressibility. The obtained results of the flammability tests clearly indicate that there is a prominent synergetic effect between the fire-retardant and the natural nanoscale additives. The nanocomposite foams containing a mixture of TPP (10 and 20 parts per hundred polyol by weight) and either 10 wt.% of nanocellulose or 20 wt.% of halloysite demonstrated the lowest burning rate without dripping and were rated as HB materials according to UL 94 classification. [ABSTRACT FROM AUTHOR]

The development of eco-friendly, mechanically stable, and biocompatible materials for medical packaging has gained significant attention in recent years. Halloysite nanotubes (HNTs) have emerged as a promising nanomaterial due to their unique tubular structure, high aspect ratio, and biocompatibility. We aim to develop a novel soybean oil-based thermoset bio-resin incorporating HNTs and to characterize its physical and functional properties for medical packaging. Soybean oil was epoxidized using an eco-friendly method and used as a precursor for preparing the thermoset resin (ESOR). Different amounts of HNTs (0.25, 0.50, and 1.0 wt.%) were used to prepare the ESOR/HNTs blends. Various characteristics such as transparency, tensile strength, thermal resistance, and water absorption were investigated. While incorporating HNTs improved the tensile strength and thermal properties of the ESOR, it noticeably reduced its transparency at the 1.0 wt.% level. Therefore, HNTs were modified using sodium hydroxide and (3-Aminopropyl) triethoxysilane (APTES) and ESOR/HNTs blends were made using 1.0 wt.% of modified HNTs. It was shown that modifying HNTs using NaOH improved the transparency and mechanical properties of prepared blends compared to those with the same amount of unmodified HNTs. However, modifying using (3-Aminopropyl) triethoxysilane (APTES) decreased the transparency but improved the water absorption of prepared resins. This study provides valuable insights into the design of HNT-based ESOR blends as a sustainable material for medical packaging, contributing to the advancement of eco-friendly packaging solutions in the healthcare industry. [ABSTRACT FROM AUTHOR]

In this work, the incorporation of halloysite nanotubes (HNTs) and polyphenylene ether-grafted maleic anhydride copolymer (FB) into acrylonitrile butadiene styrene (ABS)/polyphenylene oxide (PPO) blend has been investigated to enhance the compatibility and performance of the blends. ABS/PPO blend (AP) with the weight ratio of ABS/PPO = 70/30 with 5 wt% loading of FB and different weight contents of HNTs were elaborated by melt blending process, and their properties were studied. The SEM observation revealed that AP blend exhibited dispersed phases of PPO droplets with apparent gaps between PPO and ABS phases, indicating poor adhesion between the polymers in the blend. As the compatibilizer, FB effectively enhanced the inter-phase interaction, minimizing the formation of interfacial gaps, evidenced by the SEM images, leading to the adhesion between ABS, PPO, and HNTs phases. As a result, the mechanical performance of the AP blend was significantly improved with the addition of FB and HNTs. At 5 wt% of HNT, the AP/FB/HNT blend exhibited the tensile strength of 37.47 MPa and flexural strength of 59.09 MPa compared to 26.60 MPa and 39.45 MPa of neat AP, respectively. The glass transition temperature of the modified blends showed shifts compared to the neat AP, which indicates the improvement in miscibility of the modified-AP blends. The thermal stability and flame resistance of the blends were also enhanced with the introduction of HNTs and FB, evidenced by the V-1 rating in the UL-94 test and the increase in limiting oxygen index (LOI). These results demonstrated that the incorporation of HNTs and FB is a promising and straightforward method to improve the properties of ABS/PPO blends. [ABSTRACT FROM AUTHOR]

To address the shortcomings of poor thermal stability, easy migration, and over‐plasticization of the liquid organic phosphorus flame retardant, cresyl diphenyl phosphate (CDP), we employed halloysite nanotube (HNT) as a carrier to load CDP, thus forming a novel composite (HNT‐CDP). The results demonstrated that the CDP loaded into HNT channels was 41 wt%. HNT‐CDP composites exhibited higher thermal stability, water resistance, and flame retardancy than mixtures of HNT and CDP in epoxy resin (EP). With a loading of 15 wt%, the limiting oxygen index of EP/HNT‐CDP increased to 48.3 and achieved a V‐0 rating in UL94 tests. Additionally, HNT‐CDP exhibited better inhibitory effects on the peak heat release rate and total heat release of EP, as well as a longer time to ignition, compared with the mixture. Moreover, as opposed to EP/HNT + CDP, EP/HNT‐CDP exhibited a significant 114.5% increase in tensile strength. These excellent thermal, water resistance, and mechanical properties can be primarily attributed to the loading of CDP by HNT channels. HNT effectively utilizes the channel confinement effect to isolate CDP from directly interacting with EP. The outstanding flame retardancy is mainly due to the synergistic effect between HNT and CDP after the formation of the composite. [ABSTRACT FROM AUTHOR]

Mine permitting requires an analysis of reasonably foreseeable impacts. In pit lake models, precipitates may be invoked to reduce dissolved aqueous concentrations, and thereby perceived groundwater impacts in the event of a throughflow pit lake after mine closure. The phases selected by modelers are generally based on geochemical theory rather than empirical data, and in this context, a review of available information is helpful. The mineralogy of Spanish, German, Czechian, Australian, and USA acidic pit lakes includes schwertmannite, jarosite, alunite, amorphous ferric oxyhydroxide (AFH), ferrihydrite, goethite, hydrobasaluminite, gibbsite, amorphous iron and aluminum oxyhydroxysulfates, gypsum, barite, and clays (kaolinite, dickite, halloysite, and smectite). Conversely, alkaline pit lakes exhibit distinct inorganic precipitation of calcite, ikaite, gaylussite, and siderite entraining metal removal from solutions at pH > 7 with biogenic iron oxyhydroxides and carbonates. Microbial activity facilitates the formation and transformation of metal sulfide precipitates predominantly in alkaline pit lakes but also in acidic water bodies. Therefore, predictive pit lake studies should focus on selecting authigenic precipitates on an empirical basis where possible, or if observed in corresponding environments in the case of permitting a new pit lake, taking into consideration kinetic barriers to mineral precipitation. This study characterized amorphous iron, aluminum, and calcium precipitate with entrained arsenic, manganese, and zinc floc from the previously acidic, now alkaline Lone Tree pit lake. The formerly acidic Liberty pit lake generated primarily gypsum and AFH, while the basic former Cortez pit lake sediment comprised calcite with solid solution Ba, Cd, Mg, Mn, and Zn. [ABSTRACT FROM AUTHOR]