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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]

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]

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]

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]

Halloysite nanotubes (HNTs) have a layered structure of clay silicate minerals and a tubular shape, which is suitable for the uniform loading of small substrates and drug molecules. The inner diameter of HNTs with an acidic solvent is selectively etched to increase the loading capacity of magnetic iron–platinum (FePt) nanoparticles. The FePt nanoparticles and etched HNTs (eHNT) are then composited by vacuum decompression. The resulting product is named FePt@eHNT and is used as a contrast agent for T2‐weighted magnetic resonance imaging. According to a comprehensive analysis of the material and its magnetic properties, by adding different proportions of HNTs before and after modification, the saturation magnetization can reach 23.769 emu g−1, which is higher than that of the composite materials studied in previous studies. This is because the tubular structure promotes the orderly displacement of the FePt nanoparticles under three‐dimensional space constraints and the uniform effect of the magnetic field. In addition, the magnetothermal effect of the composite material is observed and its potential as an imaging agent is investigated. In this study, the enhancement of its ferromagnetism and its potential to become a multifunctional composite material for applications in drug delivery, magnetic hyperthermia, and bioimaging is demonstrated. [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]

Biological structures achieve remarkable material performance owing to naturally assembled structures that extend from the molecular to macro‐scale. Synergy among constituents of various length scales yields lightweight, hierarchically structured materials with properties superior to those of individual components. To replicate nature's ingenuity, this work emulates the cylindrical core‐shell structure found in osteons and bamboo, utilizing Halloysite Nanotubes (HNTs) and Glass Fibers (GFs) in a semi‐crystalline polymer matrix. HNTs are environmentally friendly, naturally occurring tubular aluminosilicates with high aspect ratios, large lumen volumes, and low cost, and are readily dispersible in polymer matrices. Here, hierarchical reinforcement is achieved through controlled electrostatic assembly of HNTs onto GFs and subsequent trans‐crystallization‐encapsulation. This cylindrical core‐shell architecture yields composites with exceptional mechanical performance, superior thermal management (insulation/stability), improved industrial processability, and reduced flame propagation speed. Compared to the current industrial composite substitute for metallic structural components, the hybrid composites exhibit a remarkable 84% increase in impact strength, 27% increase in specific tensile strength, 56% increase in tensile toughness, and 30% in specific flexural strength, accompanied by a 20% weight reduction and a 255% increase in processability (melt‐flow index). This scalable assembly strategy marks a cornerstone in lightweight multifunctional materials development, to conquer future sustainability targets. [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]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract 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.

Polypropylene is one of the most widely used synthetic resins, which is mainly synthesized with Ziegler-Natta catalysts. In this paper, the functionalized Ziegler-Natta catalyst is applied to prepare high-performance polypropylene. A new way to synthesize functionalized Ziegler-Natta catalysts is to dope with inorganic nanoparticles. The MgCl2/TiCl4/BMMF catalysts doped with halloysite nanotubes were prepared and applied to synthesize polypropylene containing less than 200ppm halloysite nanotubes. It is found that doping nanotubes in Ziegler-Natta catalyst has little impact on the structure, composition and activity of the catalyst, and polypropylene with high isotactic degree and molecular weight was synthesized with the functionalized Ziegler-Natta catalyst. Halloysite nanotubes are found to be dispersed in polypropylene in the form of individual nanotube, forming percolated network in the polymer melt effectively. Moreover, the polypropylene containing halloysite nanotubes exhibited better mechanical and thermal resistance properties as compared with conventional polypropylene, and the thermo-oxidative properties of which do not deteriorate as the introduction of nanotubes. This research provides a facile way to relieve the contradiction between the high activity of catalyst and high content of nanoparticles during the preparation of polyolefin nanocomposites by in-situ polymerization, and a new idea to prepare polyolefin nanocomposites by in-situ polymerization.

Highlights In this study, we compare synergistic performance of two different nanofillers, namely halloysite nanotubes (HNT) clay and multiwalled carbon nanotubes (MWCNT), in conjunction with a fixed concentration (0.125 phr) of semi‐anthracite coal‐derived graphene oxide (AC‐GO) on mechanical properties improvement of EGFPs (E‐glass fiber‐based epoxy resin composites). The dispersion of AC‐GO with HNT clay (GO‐H) and AC‐GO with MWCNT (GO‐C) within epoxy matrix was achieved using sonication and homogenization. Further mixture was incorporated into mats of E‐glass fiber employing “vacuum‐assisted resin infusion molding” (VARIM). Significant enhancements (18.3% flexural strength, 14.6% tensile strength, and a slight increase of impact strength (1.8%)) were observed in EGFPs reinforced with GO‐H at 0.50 phr loading of HNT, with an AC‐GO concentration maintained at 0.125 phr. Correspondingly, optimal values for GO‐C reinforced EGFPs at 0.25 phr were 40.3%, 18.7%, and a 10.5% decrease in impact strength, respectively. Analytical techniques such as XRD, FESEM, EDX mapping, and FTIR reveal presence of relatively abundant functionalities and strong interfacial adhesion in GO‐H as well as GO‐C. The cost of HNT clay is approximately 15 times cheaper than industrial‐grade MWCNTs, therefore, these results underscore potential of GO‐H as a very economical nano‐reinforcement alternative to GO‐C for polymer nanocomposites. 0.50 phr HAGRP improves 18.3% flexural, 14.6% tensile, 1.8% impact strengths. Beyond 0.50 phr HAGRP and 0.25 phr CAGRP, mechanical properties decreased. 0.25 phr CAGRP improves 40.3% flexural, and18.7% tensile strengths. FESEM, FTIR reveal strong interfacial adhesion between nanofillers and epoxy. GO‐H has proven to be an inexpensive reinforcement for polymer nanocomposites. [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]

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]

Copyright of Basic Sciences Journal of Textile Universities / Fangzhi Gaoxiao Jichu Kexue Xuebao is the property of Basic Sciences Journal of Textile Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study explores the use of Halloysite NanoTubes (HNTs) as photocatalysts capable of decomposing organic dyes under exposure to visible or ultraviolet light. Through a systematic series of photocatalytic experiments, we unveil that the photodegradation of Rhodamine B, used as a model cationic dye, is significantly accelerated in the presence of HNTs. We observe that the extent of RhB photocatalytic degradation in 100 min in the presence of the HNTs is ~four times higher compared to that of bare RhB. Moreover, under optimized conditions, the as-extracted photodegradation rate of RhB (~0.0022 min−1) is comparable to that of the previously reported work on the photodegradation of RhB in the presence of tubular nanostructures. A parallel effect is observed for anionic Coumarin photodegradation, albeit less efficiently. Our analysis attributes this discrepancy to the distinct charge states of the two dyes, influencing their attachment sites on HNTs. Cationic Rhodamine B molecules preferentially attach to the outer surface of HNTs, while anionic Coumarin molecules tend to attach to the inner surface. By leveraging the unique properties of HNTs, a family of naturally occurring nanotube structures, this research offers valuable insights for optimizing photocatalytic systems in the pursuit of effective and eco-friendly solutions for environmental remediation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bacterial infectious diseases seriously threaten global public health. The inappropriate use of antibiotics promoted the emergence and widespread of drug-resistant bacteria; thus, nanomaterial-based antibacterial agents are considered promising alternatives to combat bacterial infections. Herein, a near-infrared (NIR) light and hydrogen peroxide (H2O2) dually triggered halloysite nanotube (HNT)-based nanoplatform (HNTs@PDA/PB) as a broad-spectrum antibacterial agent was fabricated via a facile two-step strategy. Specifically, as natural clay materials, HNTs were first coated with a versatile layer of polydopamine (PDA). Then, the catechol groups on the PDA surface served as a chelating and reducing agent, facilitating the in situ growth of Prussian blue (PB) nanoparticles. The as-prepared HNTs@PDA/PB exhibited strong absorption in the NIR region and peroxidase-like activity, which suggested that it can act as a photothermal and Fenton dual-modal agent. Under NIR irradiation and exogenous H2O2, HNTs@PDA/PB exhibited excellent bactericidal activity via photothermal-enhanced chemodynamic therapy against multiple pathogenic bacteria, eliminating 68.0 ± 0.4% of the Staphylococcus aureus biofilm and 61.6 ± 0.3% of the methicillin-resistant S. aureus (MRSA) biofilm. In vivo studies further demonstrated that HNTs@PDA/PB could achieve efficient bacterial eradication and accelerate wound healing. Overall, this versatile HNT-based nanoplatform can serve as a promising therapeutic candidate to fight against bacterial infectious diseases. [ABSTRACT FROM AUTHOR]

Highly flame‐resistant epoxy composites have important application value in many industrial fields. Unfortunately, epoxy resins (EPs) are inherently flammable materials and exhibit great fire hazard. In this study, the commercially available 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) was chemically immobilized on the surface of natural halloysite nanotubes (HNTs) via the linkage of vinyltrimethoxysilane to obtain a novel flame‐retardant VD@HNTs containing P/Si/Al elements. It was found that the flame‐retardant VD@HNTs can effectively improve the thermal stability and flame resistance of epoxy composites. Typically, when 10% of VD@HNTs is added in EP, the limiting oxygen index of as‐prepared VD@HNTs/EP composites reaches 30.3%, and it also successfully reaches V‐0 classification in the UL‐94 test. Besides, the ignition time of VD@HNTs/EP composites was enhanced from 42 s for pure EP to 60 s, and the maximum heat release rate was reduced from 1221 to 758 kW∙m−2. These great findings promise an innovative and efficient strategy for improving the fire safety of EP products and may also offer valuable insight toward fabricating various novel organic–inorganic flame retardants as well as highly flame‐resistant polymer composites. Highlights: A novel flame‐retardant VD@HNTs containing P/Si/Al elements was prepared by the chemical decoration of HNTs with organophosphorous.The VD@HNT can effectively improve the thermal stability and flame resistance of epoxy composites.Synergistic flame‐retardant mechanism of phosphorus‐based flame retardants and natural HNTs was classified. [ABSTRACT FROM AUTHOR]

Antifouling epoxy resin serves as a member of advanced nanocomposite coatings and engineered surfaces. Nevertheless, developing an antifouling epoxy composites is a state‐of‐the‐art technology. Herein, a complex nanostructure is tailored to be served as an advanced additive giving the antifouling characteristics to the epoxy resin. F‐POSS@HNT hybrid nanostructure, that is, halloysite nanotubes (HNTs) decorated with fluorinated polyhedral oligomericsil sesquioxane (F‐POSS), was synthesized and characterized. Chemical structure changes, thermal stability and morphology of hydroxylated HNTs (hHNTs) intermediate and F‐POSS@HNT ultimate nanostructures were analyzed by FTIR spectroscopy, TGA and TEM, respectively. The F‐POSS@HNTs catalyzed the epoxy‐amine crosslinking reaction, taking "Good" or "Excellent" crosslinking tags an quantified by the "Cure Index." The apparent activation energy values were calculated for the epoxy (reference), epoxy/hHNTs, and epoxy/F‐POSS@HNTs systems (26, 51, and 47 kJ mol−1, respectively). Contact angle measurements were performed via dynamic tests demonstrating improved hydro‐ and oleophobicity of the thermoset composites. The advancing contact angle with diiodomethane increased 36% and 30% for nanocomposites containing 5 and 10 wt.% of the developed hybrid nanostructure, respectively, compared with the neat epoxy. Likewise, 54% and 67% reduction in paraffin fouling in the same order confirmed their antifouling ability. Regarding self‐cleaning characteristics, 24% and 33% surface recovery were observed, respectively. Highlights: Antifouling surface was achieved in epoxy thermoset nanocomposites for potential industrial applications.Self‐cleaning behavior correlated with low wetting and antifouling properties.F‐POSS@HNT nanofillers were synthesized and successfully added to epoxy matrix.Both hHNT and F‐POSS@HNT showed a beneficial autocatalytic effect on epoxy‐amine reaction yielding satisfactory polymer crosslinking.Activation energy was reduced by incorporating F‐POSS@HNT compared with hHNT, signature of facilitated crosslinking. [ABSTRACT FROM AUTHOR]

Biodegradable packaging plastics combining good mechanical properties and low gas permeability is required to avoid environmental and food safety concerns. This study explores the impact of montmorillonite (MMT) and halloysite nanotubes (HNT), on the mechanical, optical, and oxygen permeability of blown film poly (butylene adipate‐co‐terephthalate) (PBAT) composites. The morphology of the films was evaluated by x‐ray diffraction (XRD), differential scanning calorimetry and scanning electron microscopy. Good distribution/dispersion of clays is found in the PBAT‐MMT films. Besides, there is an increase in the crystallinity of PBAT due to the nucleating effect of HNT. Improvement in the tensile strength and elongation at break in the machine direction is obtained up to a clay content of 1.5 vol%. The incorporation of 1.5 vol% of MMT and 1 vol% of HNT leads to a reduction in the oxygen permeability of the PBAT film by 29% and 38% respectively. Furthermore, the films remain transparent regardless of clay content. Finally, the feasibility of the films for food storage is tested in grapes, obtaining extended shelf life. The favorable mechanical, barrier and optical properties of the biodegradable films, along with the scalable production process, make them attractive for application in the storage and preservation of food products. [ABSTRACT FROM AUTHOR]

Halloysite nanotubes (HNTs) and polypropylene-grafted maleic anhydride (PP-g-MA) were studied for their effects in blends of polystyrene (PS) and polyolefin elastomer (POE). The method used to prepare PS/POE blends (90/10 and 80/20 wt/wt) containing 1, 3, and 5 phr HNTs with or without PP-g-MA (a compatibilizer) was melt blending. Structural and morphological studies using X-ray diffraction analysis (XRD), scanning electron microscopy assisted energy dispersive X-ray spectroscopy (SEM-EDS), and transmission electron microscopy (TEM) confirmed a matrix-droplet morphology and the sample containing compatibilizer has better microstructure than the other formulations. The presence of both PP-g-MA and HNTs together has been discovered to improve the viscoelastic properties of the solid, as evidenced by increased storage modulus and complex viscosity. A notable change occurred in the rheological behavior of the PS/POE blends containing 5 phr of PP-g-MA and HNTs. The dependence of zero-shear viscosity on HNTs loading (0–5 phr) was approximated as a polynomial curve by fitting the experimental data with the Carreau-Yasuda model. Computational fluid dynamics (CFD) simulations were also used to study the effects of HNTs loading on changes in fluid flow patterns and shear rates. The calculated effective viscosities at a given shear rate (0.05 1/s) were in qualitative agreement with the experimental results. Moreover, we utilized various machine-learning techniques to predict the complex viscosity of PS/POE blends and their nanocomposites. The results showed that Extreme Gradient Boosting (XGBoost) outperformed other predictive models based on evaluation metrics. Four-point probe measurements found that the samples containing 5 phr HNT had the lowest conductivities due to the presence of aggregated structures. However, the homogeneous distribution of HNT led to a sudden rise in conductivity in the samples containing 5 phr of PP-g-MA. Computer modeling results of samples with uniform and non-uniform HNT distributions showed that the conductivity decreased with HNT loading and decreased considerably compared to the uniform distribution.

Halloysite nanotubes (HNTs) have a layered structure of clay silicate minerals and a tubular shape, which is suitable for the uniform loading of small substrates and drug molecules. The inner diameter of HNTs with an acidic solvent is selectively etched to increase the loading capacity of magnetic iron–platinum (FePt) nanoparticles. The FePt nanoparticles and etched HNTs (eHNT) are then composited by vacuum decompression. The resulting product is named FePt@eHNT and is used as a contrast agent for T2‐weighted magnetic resonance imaging. According to a comprehensive analysis of the material and its magnetic properties, by adding different proportions of HNTs before and after modification, the saturation magnetization can reach 23.769 emu g−1, which is higher than that of the composite materials studied in previous studies. This is because the tubular structure promotes the orderly displacement of the FePt nanoparticles under three‐dimensional space constraints and the uniform effect of the magnetic field. In addition, the magnetothermal effect of the composite material is observed and its potential as an imaging agent is investigated. In this study, the enhancement of its ferromagnetism and its potential to become a multifunctional composite material for applications in drug delivery, magnetic hyperthermia, and bioimaging is demonstrated.

This study explores the use of Halloysite NanoTubes (HNTs) as photocatalysts capable of decomposing organic dyes under exposure to visible or ultraviolet light. Through a systematic series of photocatalytic experiments, we unveil that the photodegradation of Rhodamine B, used as a model cationic dye, is significantly accelerated in the presence of HNTs. We observe that the extent of RhB photocatalytic degradation in 100 min in the presence of the HNTs is ~four times higher compared to that of bare RhB. Moreover, under optimized conditions, the as-extracted photodegradation rate of RhB (~0.0022 min−1) is comparable to that of the previously reported work on the photodegradation of RhB in the presence of tubular nanostructures. A parallel effect is observed for anionic Coumarin photodegradation, albeit less efficiently. Our analysis attributes this discrepancy to the distinct charge states of the two dyes, influencing their attachment sites on HNTs. Cationic Rhodamine B molecules preferentially attach to the outer surface of HNTs, while anionic Coumarin molecules tend to attach to the inner surface. By leveraging the unique properties of HNTs, a family of naturally occurring nanotube structures, this research offers valuable insights for optimizing photocatalytic systems in the pursuit of effective and eco-friendly solutions for environmental remediation.

Due to its versatile properties polyvinyl chloride (PVC) based materials are employed in several applications. At high temperatures and in acidic media PVC is prone to release toxic materials into the environment. Several reports are available in the literature about the modification of PVC to minimize such problems. Herein, an attempt is made to prepare PVC/Halloysite nanotube (HNT) nanocomposites with a fixed amount of compatibilizer, OPTIM GE 344 (maleic anhydride modified very low-density polyethylene (VLDPE)) and characterize the composites with respect to thermal stability, mechanical properties, and structural aspects. Both tensile and flexural strength showed appreciable improvement for the 4 wt% loading of the nanofiller. Thermogravimetric analysis (TGA) showed that the maximum degradation temperature improved by approximately 24 °C for 4 wt% filled composites. PVC thermomat measurements of the samples were used to study the thermal stability of the composites. PVC without HNT showed 36 min as the stability time and it increased to 398 min for 4 wt% of HNT loading. To complement the thermal properties of the composites, the mass loss measurement and contact angle behavior of the composite surfaces were also done. The decrease in contact angle values denoted better surface wettability properties. The mass loss measurements showed a decrease with respect to the filler loading of HNT, indicating a better interaction between the polymer matrix and HNT.

Corrosion is a major problem that can lead to the degradation of metal structures. In this study, we developed a novel corrosion-protective coating for metal substrates based on a modified epoxy acrylate formulation reinforced with halloysite nanotubes (HNTs). Epoxy acrylate oligomers were first synthesized through the acrylation of epoxy using acrylic acid, followed by copolymerization with butyl methacrylate/vinyl acetate monomers to produce grafted epoxy acrylates (GEA). HNTs were then incorporated into the polymeric dispersion at weight loadings of 1%, 1.5%, and 2%. The corrosion resistance and waterproofing properties of the coatings were evaluated. The results showed that steel samples coated with HNTs-modified GEA showed no signs of rusting even after 16 days of immersion in a corrosive solution, whereas those coated with GEA alone showed rusting after only 9 days. These results demonstrate the effectiveness of HNTs- modified GEA coatings in protecting steel surfaces against corrosion. The coatings are also water-resistant and can be easily applied. This work provides a new approach to developing corrosion-protective coatings for metal substrates. [ABSTRACT FROM AUTHOR]

The control of the localization of halloysite nanotubes (HNT) in a linear low-density polyethylene/ethylene-vinyl acetate copolymer (LLDPE/EVA, 70/30) blend was studied through three approaches: i) Functionalization of the filler, ii) Addition of a compatibilizer and iii) Modification of the processing sequence. First, the HNT surface modification was carried out with three different organosilanes (3-aminopropyltriethoxysilane (APTES), dodecyltricholosilane (DTCS) and triacontyltrichlorosilane (C30)). Grafting amounts about 0.10 mmol/g were reached whatever the nature of the organosilane. Then, the unmodified and modified HNT were mixed with a LLDPE/EVA (70/30) polymer blend using a microextruder and the localization of the fillers were scrutinized by scanning electron microscopy (SEM) analysis. It was observed that both the neat HNT and modified HNT were mostly localized in the EVA phase. These observations were also discussed according to the wettability coefficient determined for neat HNT and modified HNT thanks to contact angle measurements. The addition of PE-g-MA as a compatibilizer to the blend containing the HNT-APTES allowed to localize the HNT in the LLDPE phase. Finally, the influence of the mixing sequence of the different components was evaluated by using a twin-screw extruder, and it was successfully used to localize the modified HNT into the LLDPE phase. [ABSTRACT FROM AUTHOR]

The study focuses on the synthesis and characterization of Meloxicam–halloysite nanotube (HNT) composites as a viable approach to enhance the solubility and dissolution rate of meloxicam, a poorly water-soluble drug (BCS class II). Meloxicam is loaded on commercial and modified halloysite (acidic and alkaline etching, or APTES and chitosan functionalization) via a solution method. Several techniques (XRPD, FT-IR, 13C solid-state NMR, SEM, EDS, TEM, DSC, TGA) are applied to characterize both HNTs and meloxicam–HNT systems. In all the investigated drug–clay hybrids, a high meloxicam loading of about 40 wt% is detected. The halloysite modification processes and the drug loading do not alter the structure and morphology of both meloxicam and halloysite nanotubes, which are in intimate contact in the composites. Weak drug–clay and drug-functionalizing agent interactions occur, involving the meloxicam amidic functional group. All the meloxicam–halloysite composites exhibit enhanced dissolution rates, as compared to meloxicam. The meloxicam–halloysite composite, functionalized with chitosan, showed the best performance both in water and in buffer at pH 7.5. The drug is completely released in 4–5 h in water and in less than 1 h in phosphate buffer. Notably, an equilibrium solubility of 13.7 ± 4.2 mg/L in distilled water at 21 °C is detected, and wettability dramatically increases, compared to the raw meloxicam. These promising results can be explained by the chitosan grafting on the outer surface of halloysite nanotubes, which provides increased specific surface area (100 m2/g) disposable for drug adsorption/desorption. [ABSTRACT FROM AUTHOR]

The superior physical and mechanical performances of halloysite nanotubes (HNTs) make them ideal fillers for rubber reinforcement. However, due to the abundant hydroxyl groups on their surface, they are highly polar and have poor compatibility with polymers, making it difficult for them to disperse uniformly in polymers, thus limiting their application in rubber composites to a certain extent. In this paper, noncovalently modified HNTs filled with a natural rubber/chloroprene rubber/chloro-isobutylene-isoprene rubber (NR/CR/CIIR) blend system, using polydopamine(PDA) as a surface modifier, was investigated. and a green and high-performance PDA/HNTs/NR/CR/CIIR composite was prepared by mechanical blending. Transmission electron microscopy (TEM) showed that the original HNTs had a hollow, multi-walled nanotube structure, and the outer surface of the PDA-modified halloysite nanotubes(PDA/HNTs)showed an obvious cladding layer. X-ray diffraction indicated that the modification experiments did not damage the halloysite crystal structure; the modifier only interacted on the outer surface of the HNTs. Zeta potential and thermogravimetric analysis (TGA) further indicated the presence of interfacial interactions between PDA and HNTs, suggesting that PDA was successfully grafted to the surface of HNTs. In addition, the effects of PDA/HNTs on the mechanical properties, vulcanization properties and Rubber Process Analyzer (RPA analysis) of the NR/CR/CIIR blend were also investigated. The dispersion of HNTs in the NR/CR/CIIR blend was enhanced by the adsorption of PDA on the HNTs surface by non-covalent bonds, and the comprehensive properties of the composites were improved. [ABSTRACT FROM AUTHOR]

[Display omitted] Gel actuators are a kind of soft intelligent material that can convert external stimuli into deformations to generate mechanical responses. The development of gel actuators with advanced structures to integrate multiple responsiveness, programmability, and fast deformation ability is urgently needed. Here, we explored a poly(7-(2-methacryloyloxyethoxy)-4-methylcoumarin- co -acrylic acid- co -glycol) ternary gel network as an actuator with reprogrammable photo/H 2 O dual responsibilities. In such a design, [2 + 2] photodimerization and photocleavage reactions of coumarin moieties can be realized under 365 and 254 nm light irradiation, respectively, affording reversible photodriven behaviour of the gels. The abundant carboxylic acid in the backbone has the capacity to form additional crosslinks to assist and accelerate the photodriven behaviour. The incorporation and orientation of halloysite nanotubes (HNTs) in gel matrices support an axial direction force and result in a more controllable and programmable actuating behaviour. The synergistic response enables fast grasping-releasing of 5-times the weight of the object in water within 10 min by fabricating HNT-incorporated gels as a four-arm gripper. [ABSTRACT FROM AUTHOR]

Gallic acid is a renewable plant phenolic resource, and the polyphenolic bio‐based epoxy resin prepared from it can be used as a substitute for bisphenol A epoxy resin in certain fields. However, bio‐based epoxy resins used in the field of high‐performance composite material matrices often require modification. In this paper, firstly, γ‐(2,3‐epoxypropoxy)propyl trimethoxysilane (KH560) was used as the raw material to prepare epoxy‐based cage silsesquioxanes (E‐POSS). Then, E‐POSS was grafted onto γ‐aminopropyltriethoxysilane (KH550) modified halloysite nanotubes (m‐HNTs) to prepare a novel hybrid nanoparticle HNTs‐e‐POSS. Experimental analysis shows that ring opening reactions of amino and epoxy groups can occur between m‐HNTs and E‐POSS, forming a hybrid nanoparticle system of POSS aggregates on the surface of HNTs. Bio‐based nanocomposites were prepared by adding different mass fractions of hybrid nanoparticles HNTs‐e‐POSS into polyphenol type gallic acid epoxy resin matrix (GAER) and using methyltetrahydrophthalic anhydride as curing agent. The properties and micromorphology of the composite were analyzed and characterized. The research showed that with the addition of HNTs‐e‐POSS nanoparticles, the strength and toughness of the composite resin system show a pattern of first increasing and then decreasing, while the storage modulus(E′), glass transition temperature (Tg), and thermal stability of the composite material increased. Mechanical performance analysis shows that the introduction of 0.5 wt% HNTs‐e‐POSS would increase the tensile strength of the composite by 25.46%, while adding 0.75 wt% HNTs‐e‐POSS can increase the impact strength by 15%. The E′(30°C) increased by 24.2% and Tg increased by 7.7°C when the HNTs‐e‐POSS addition was 0.25 wt%. Highlights: Prepared hybrid nanoparticle HNTs‐e‐POSS by grafting POSS onto the HNTs surface.Application of HNTs‐e‐POSS in modification of bio‐based gallic acid epoxy resin.HNTs‐e‐POSS can co‐cured with epoxy matrix to increase the crosslinking degree.The strength, toughness, and modulus of gallic acid epoxy resin are improved.Tg and thermal stability of gallic acid epoxy resin are enhanced. [ABSTRACT FROM AUTHOR]

UV radiation is the main cause of skin aging and cancers. Commercial sunscreens suffer from low efficacy and poor safety, while ceria nanocrystals are promising inorganic UV filters. Herein, the lumen of natural halloysite clay nanotubes (HNTs) is employed for the confined growth of ceria nanocrystals, which can effectively tailor the particle size, morphology, distribution, and oxygen vacancies of the ceria. The ceria in HNTs lumen exhibits increased UV protection and catalytic activity, while the outer surfaces of HNTs can be retained for additional modification. Ceria‐loaded HNTs (named CeOx@HNTs) can act as oil–water interfacial stabilizers to develop skin‐friendly Pickering emulsion sunscreens. Attributed to the Pickering emulsion interfacial catalytic effect of CeOx@HNTs, the UV absorption performance of the sunscreens is enhanced by 3.1 times after emulsification, achieving a sun protection factor of 58.5. In vitro and in vivo studies confirm the effectiveness of the prepared sunscreen in mitigating DNA damage, apoptosis, and malignant transformation. In addition, the sunscreen inhibits biofilm formation by disturbing membrane homeostasis through oxidative stress. This work develops a confined‐growth method of rare earth oxides within tubular nanoclays, which shows promising applications in many fields, such as aging resistance, photoluminescence, and chemical catalysis. [ABSTRACT FROM AUTHOR]

Due to its versatile properties polyvinyl chloride (PVC) based materials are employed in several applications. At high temperatures and in acidic media PVC is prone to release toxic materials into the environment. Several reports are available in the literature about the modification of PVC to minimize such problems. Herein, an attempt is made to prepare PVC/Halloysite nanotube (HNT) nanocomposites with a fixed amount of compatibilizer, OPTIM GE 344 (maleic anhydride modified very low-density polyethylene (VLDPE)) and characterize the composites with respect to thermal stability, mechanical properties, and structural aspects. Both tensile and flexural strength showed appreciable improvement for the 4 wt% loading of the nanofiller. Thermogravimetric analysis (TGA) showed that the maximum degradation temperature improved by approximately 24 °C for 4 wt% filled composites. PVC thermomat measurements of the samples were used to study the thermal stability of the composites. PVC without HNT showed 36 min as the stability time and it increased to 398 min for 4 wt% of HNT loading. To complement the thermal properties of the composites, the mass loss measurement and contact angle behavior of the composite surfaces were also done. The decrease in contact angle values denoted better surface wettability properties. The mass loss measurements showed a decrease with respect to the filler loading of HNT, indicating a better interaction between the polymer matrix and HNT. [ABSTRACT FROM AUTHOR]

One of the steps in scaling the technology for the synthesis of zeolite-containing catalysts from the laboratory to commercial level is support forming. In this study, halloysite nanotubes and aluminum oxide were used as binders for preparing a support based on MFI (ZSM-5) zeolite. The Pt catalysts (Pt/ZSM-5/Al2O3 and Pt/ZSM-5/Hall) were tested in isomerization of the aromatic C8 fraction. The forming of supports influenced not only mechanical but also physicochemical properties of the catalysts. On introducing binders into the catalytic system, the fraction of mesopores in the total pore volume of the supports increased, the acidity of the samples decreased, and the ratio of the amounts of the weak and strong acid sites changed. The use of aluminum oxide and halloysite as binders leads to different pathways of the transformation of the aromatic feedstock. The main side reactions observed in the presence of Pt/ZSM-5/Al2O3 and Pt/ZSM-5/Hall catalysts are hydrocracking of alkylaromatic hydrocarbons and their transalkylation/disproportionation, respectively. The best results were obtained at 380°C and feed space velocity of 6 h–1 with Pt/ZSM-5/Hall: p-/о-xylene ratio 1.05, loss of xylenes 4.31%, and ethylbenzene conversion 34%. [ABSTRACT FROM AUTHOR]

In the biomedical field, polyvinyl alcohol (PVA) sponge has been widely used. In particular, it is considered a potential implant material for repairing soft tissues. However, its insufficient water absorption and mechanical properties limit its application. In this work, a novel PVA/halloysite nanotubes (HNTs)/gelatin ternary composite sponge was prepared by water solution mixing and casting techniques. HNTs and gelatin/PVA solution were mixed at different weight ratios. The structure of the ternary composite sponges was characterized by using scanning electron microscopy. The physical properties of the ternary composite sponges were characterized. The maximum water absorption reached 1783.5% with a rapid water absorption speed at a weight ratio of HNTs/gelatin of 1:8. Owing to its interconnected macroporous structure and good interfacial interaction, its highest compression strength and tensile strength reached 8.22, 1.51 MPa, respectively. In addition, its thermal stability was enhanced as well, which demonstrated that the prepared composite sponge had better performance than the pure PVA sponge by constructing a ternary system. Therefore, the results suggest that the PVA/HNTs/gelatin ternary composite sponge shows a wider application value as a potential material for repairing soft tissue. Highlights: A composite PVA sponge with promising applications in tissue engineering.Simple preparation method, water solution mixing and casting techniques.Pioneering a PVA/HNTs/gelatin ternary system sponge.Improved water absorption ability and mechanical properties. [ABSTRACT FROM AUTHOR]

There is an urgent need to develop an efficient approach to limit biofilm formations. Recent progress in the biofilm treatment field showed remarkable utilization of emerging nanoformulations. In this study, we decorated clay halloysite nanotubules with tannic acid and Fe3O4 Nanoparticles. The successful synthesis of the nanocomposite was validated by characterization techniques such as XRD, FE-SEM, HR-TEM, SEM-EDS, TEM-EDS, XPS, and VSM analysis. After successful characterizations of nanocomposite (HNTs-M-Tannic acid), antibiofilm effect analysis experiments such as Crystal Violet (CV) staining, biofilm-forming marker gene expression analysis, morphology evaluation by SEM, and live and dead cell assay were performed. The Crystal Violet (CV) staining results concluded a significant 57.8% inhibition of the E. coli biofilm formation. Comprehensive gene expression analysis of fimA and csgA for E. coli biofilm formation confirmed the capacity of HNTs-M-Tannic acid to impede bacterial cell adhesion, thereby inhibiting biofilm formation. The SEM images and live and dead assay results confirmed and marked the potential of the developed HNTs- M-Tannic acid as an antibiofilm agent against E. coli. In conclusion, this study produced a unique nanocomposite, HNTs-M-Tannic acid, which offers potential as an economically viable, magnetically separable, and biocompatible nanoformulations for antibiofilm studies. [ABSTRACT FROM AUTHOR]

This study aimed to explore the reinforcement effect of halloysite nanotubes (HNTs) in self‐healing natural rubber based on metal thiolate ion networks. The amount of HNTs was varied at five levels (2, 4, 6, 8, and 10 phr) in order to assess the optimum amount of filler for self‐healing efficiency and mechanical recovery performance. Fourier‐transform infrared (FTIR) provides evidence for the reversible ionic bonding, facilitated by Zn2+ and S− bonding from the metal thiolate vulcanization with rubber molecular chains. Scanning electron microscopy (SEM) revealed that the NR/HNTs composites with lower filler loading exhibited better recovery, as there were no observable gaps between the cut surfaces of the samples. The results also revealed that addition of HNTs resulted in a significant improvement in the mechanical performance, particularly the tensile strength, which increased by approximately 20%–75%. Furthermore, the extent of healing after the broken pieces were brought in contact with each other varied from 87% to 98%, depending on HNT concentration. Highlights: Fabrication of self‐healing elastomers based on natural rubber.Self‐healing NR presented enhanced mechanical performance with addition of HNTs.HNTs lumen endows the composites with excellent self‐healing efficiency.Developed NR/HNTs composite exhibited room temperature self‐healing properties.Reversible ionic bonding expedited by Zn2+ contributes in excellent self‐healing. [ABSTRACT FROM AUTHOR]

Nanotechnology, rather than traditional medicinal procedures like chemotherapy, now helps to reduce adverse effects. There is a great demand for a biocompatible nanocarrier with a long half-life, high bioavailability, and capable of imaging cells and targeting them selectively. A procedure known as water-in-oil-in-water (W/O/W) emulsification was employed to produce hybrid nanohydrogels containing agarose, polyvinyl alcohol, halloysite nanotubes, and 5-fluorouracil (AGA-PVA-HNT@5-Fu) which can be highly effective for decreasing the particle size of nanohydrogels and improving their uniformity. These hydrogels were produced to specifically target and administer the 5-Fu anti-cancer drug for the treatment of breast cancer. Following the evaluation of physicochemical characteristics, both a substantial drug loading and efficient trapping were accomplished. The nanohydrogels displayed a zeta potential of −38.4 mV indicative of a good stability due to the usage of span 80. Based on the drug release profile conducted in vitro, it was observed that AGA-PVA-HNT@5-Fu released the medication in a regulated way. By using MTT and flow cytometry analysis, it was found that AGA-PVA-HNT@5-Fu could effectively eliminate tumor cells, while the blank nanoparticles proved to be biocompatible. The results indicate that hybrid nanohydrogels based on AGA-PVA-HNT@5-Fu can be utilized as nanohydrogels for treating breast cancer.

Biologically self-healing concretes are generally composed of immobilized or encapsulated bacterial spores and nutrients. The efficiency of this self-healing approach depends on the effective protection and storage by the carriers. This report describes a novel sustained-release strategy for the improved self-healing function and microcapsule resistance to the cement environment. Halloysite clay nanotubes (HNTs) loaded with the common microbiological nutrient, yeast extract (YE) were encapsulated in calcium alginate microcapsules alongside Bacillus pseudofirmus spores. The encapsulation of the YE-loaded HNTs improved the resistance of the microcapsules to the cement environment, improved the microcapsule-cement interface, while successfully retaining the nutrients after direct contact with the cement pore solution. The self-healing system effectively healed artificial concrete cracks compared to control samples, reducing the crack water tightness by over 95%, and improved the flexural strength regain by approximately 75% after 56 days of wet-dry incubation. The sustained-release mechanism considerably improved the self-healing performance.

In the present work, halloysite nanotubes modified with gold nanoparticles (AuNPs-HNT) are successfully prepared by wet chemical method for the catalytic degradation of phenothiazine dyes (azure B (AZB) and toluidine blue O (TBO)) and also cleaner reduction of 4-(4-nitrophenyl)morpholine (4NM) in the sodium borohydride (NaBH4) media. The catalyst is formulated by modifying the HNT support with a 0.964% metal loading using the HNT supports modified with 3-aminopropyl-trimethoxysilane (APTMS) coupling agent to facilitate the anchoring sites to trap the AuNPs and to prevent their agglomeration/aggregation. The AuNPs-HNT catalyst is investigated for structural and morphological characterization to get insights about the formation of the catalyst for the effective catalytic reduction of dyes and 4NM. The microscopic studies demonstrate that AuNPs (2.75 nm) are decorated on the outer surface of HNT. The as-prepared AuNPs-HNT catalyst demonstrates AZB and TBO dye degradation efficiency up to 96% in 10 and 11 min, respectively, and catalytic reduction of 4NM to 4-morpholinoaniline (MAN) is achieved up to 97% in 11 min, in the presence of NaBH4 without the formation of any by-products. The pseudo-first-order rate constant (K1) value of the AuNPs-HNT catalyst for AZB, TBO, and 4NM were calculated to be 0.0078, 0.0055, and 0.0066 s−1, respectively. Moreover, the synthesized catalyst shows an excellent reusability with stable catalytic reduction for 7 successive cycles for both the dyes and 4NM. A plausible mechanism for the catalytic dye degradation and reduction of 4NM by AuNPs-HNT catalyst is proposed as well. The obtained results clearly indicate the potential of AuNPs-HNT as an efficient catalyst for the removal of dye contaminants from the aquatic environments and cleaner reduction of 4NM to MAN, insinuating future pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Combining biologically active compounds with nanocarriers is an emerging and promising strategy for enhancing the activities of molecules while reducing their levels of toxicity. Green nanomaterials have recently gained momentum in developing protocols for treating and preserving artifacts. In this study, we designed a functional biohybrid material by incorporating tributyltin(IV) ferulate (TBT-F) into halloysite nanotubes (HNTs), generating a new formulation called HNT/TBT-F. The primary objective was to develop a formulation with robust antimicrobial properties and reinforcing features for treating paper with artistic and historical value. To characterize HNT/TBT-F, assess the HNT's loading capacity, and investigate the TBT-F release kinetics from the nanotubes, various analytical techniques, including UV-Vis and infrared spectroscopies, thermogravimetry, and microscopy analysis, were employed. Furthermore, we evaluated the antimicrobial potential of TBT-F and HNT/TBT-F against Kocuria rhizophila, a bacterial strain known for its opportunistic behavior and a cause of artifact biodeterioration. HNT/TBT-F exhibited a significantly stronger bactericidal effect than TBT-F alone against K. rhizophila cells growing planktonically or those forming a biofilm. This enhanced performance could relate to the confinement of TBT-F within the nanotubes, which likely improved its physical-chemical stability and increased the local concentration of TBT-F upon contact with the bacterial cells. Additionally, we evaluated the mechanical properties of a paper treated with HNT/TBT-F, assessing any potential alterations in its color. The findings of this study highlight the favorable attributes of the HNT/TBT-F formulation and its potential for developing protocols aimed at consolidating and preserving culturally significant paper objects. [ABSTRACT FROM AUTHOR]

Nine halloysite nanotubes (HNTs) have been examined using scanning electron microscopy (SEM), atomic force microscopy (AFM) and (cross-sectional) transmission electron microscopy (TEM) to evaluate details of their external and internal morphologies. The samples span morphologies within the cylindrical to prismatic-polygonal framework proposed by Hillier et al. (2016). The 'carpet roll' model assumed in the conceptualization of most technological applications of HNTs is shown to be far too simplistic. Both cylindrical and prismatic forms have abundant edge steps traversing their surfaces that, by analogy with plates of kaolinite, correspond to prism faces. The mean value for the diameter of the central lumen of the tubes is 12 nm. Numerous slit-like nanopores, with diameters up to 18 nm, also occur between packets of layers, particularly in prismatic forms at the junction between a central cylindrical core and outer packets of planar layers. These pores expose aluminol and siloxane surfaces, but unlike the lumen, which is assumed only to expose an aluminol surface, they do not extend along the entire length of the nanotube. Edge steps seen most clearly by AFM correspond in height to the packets of layers seen in TEM. TEM cross-sections suggest that tube growth occurs by accretion of a spiralled thickening wedge of layers evolving from cylindrical to polygonal form and reveal that planar sectors may be joined by either abrupt angular junctions or by short sections of curved layers. A more realistic model of the internal and external morphologies of HNTs is proposed to assist with understanding of the behaviour of HNTs in technological applications. [ABSTRACT FROM AUTHOR]

In this research work, a reusable and efficient 2D/1D heterogeneous structured photocatalyst based on amine-functionalized halloysite nanotubes (MHNTs) and Bi2WO6 nanosheet (BWO) was prepared using a facile hydrothermal method for decomposing PPCPs under simulated sunlight. On the degradation of tetracycline hydrochloride (TCH), the effects of composite catalysts prepared under various conditions were discussed. The results showed that over BWO/MHNTs with a mass ratio was 3:1, the synthesizing temperature was 120 °C and the precursor pH value was 1, the TCH (10 mg l−1) degradation efficiency reached 100% after 1 h irradiation of simulated sunlight. Moreover, BWO/MHNTs composites kept good recovery and stable photocatalytic activity after 5 cycles. The excellent dispersion of Bi2WO6 on the surface of clay minerals and the oxygen vacancy enhanced electron–hole separation may be responsible for the its high activity and stability. Futhermore, the radical capture test demonstrated that ·O−2 was primarily responsible for the photodegradation of TCH. Thus, BWO/MHNTs composites exhibit a good application prospect in the field of sunlight-driven photocatalytic degradation towards PPCPs pollutants in water. [ABSTRACT FROM AUTHOR]

The production of Schottky junctions between ZIS and Pt, the high utilization of light energy in tubular HNTs, and the trapping effect of EDTA for photogenerated h+ were all favorable for enhancing the catalytic property. [Display omitted] • Halloysite (HNTs) were as substrates to in-situ grow ZnIn 2 S 4 (ZIS) nanoflowers. • Composite 3ZIS-HNTs/E3 exhibited enhanced photocatalytic H 2 evolution rate. • 3ZIS-HNTs/E3 displayed excellent capacity for 4-nitrophenol hydrogenation reaction. • HNTs induced higher S vacancies, dispersion, and light energy utilization in ZIS. • Schottky junctions (Pt and ZIS) enhanced the separation of photogenerated carriers. Hydrogen (H 2) evolution by photocatalytic water splitting is a potential strategy to solve worldwide energy shortage. Sulfide nanocatalysts showed great potential for H 2 evolution, but suffered from low charge separation efficiency and easy agglomeration. In this work, ZnIn 2 S 4 (ZIS) nanoflowers were anchored onto the surface of halloysite nanotubes (HNTs) modified by ethylenediaminetetraacetic acid (EDTA). Photocatalyst 3ZnIn 2 S 4 -HNTs/EDTA3 (3ZIS-HNTs/E3) displayed the optimum H 2 evolution rate of 10.4 mmol·g−1·h−1, being 3.4 times as that of the original ZIS. Moreover, 3ZIS-HNTs/E3 presented satisfied property in the photocatalytic hydrogenation reaction of 4-nitrophenol to produce 4-aminophenol. HNTs as substrates not only hindered the growth and agglomeration of ZIS, but also induced more S vacancies in ZIS. The production of Schottky junctions between ZIS and Pt, the high utilization of light energy in tubular HNTs, and the trapping effect of EDTA for photogenerated h+ were all favorable for enhancing the catalytic property. The density functional theory (DFT) calculations showed that 3ZIS-HNTs/E3 with more S vacancies had the lowest adsorption energy and the most appropriate Δ G H* for H* to enhance the H 2 evolution efficiency, which was consistent with the experimental catalytic results. This study contributes a novel thought for synthesizing composites on the basis of natural minerals for taking part in and enhancing the catalytic performance. [ABSTRACT FROM AUTHOR]

This study involves the incorporation of halloysite nanotubes (HNTs) modified with 3-Aminopropyltriethoxysilane (APTES) into blends of ethylene-propylene diene monomer (EPDM) and styrene-butadiene rubber (SBR). We investigate the effects of APTES-modified HNTs on the curing behavior, mechanical properties, microstructure, and swelling resistance of 80/20 phr/phr EPDM/SBR composites. The addition of APTES-modified HNTs results in an increase in minimum torque, maximum torque, and delta torque in the EPDM/SBR composites. However, both scorch time and optimal cure time decrease with higher APTES-modified HNTs content. Notably, composites containing 6 phr of APTES-modified HNTs exhibit a remarkable 121% enhancement in tensile strength and a 59% increase in stress at 100% elongation. The tear strength, hardness, and abrasion resistance of the EPDM/SBR composites increase, while the elongation at break, rebound resilience, and mole percent uptake decrease. Overall, APTES-modified HNTs filler-filled EPDM/SBR nanocomposites demonstrate superior performance compared to those filled with unmodified HNTs. [ABSTRACT FROM AUTHOR]

Two kinds of Al‐based metal‐organic frameworks (Al‐MOFs), MIL‐53(Al), and MIL‐96(Al), were synthesized by the solvothermal method and then characterized using SEM, XRD, and FTIR. The Al‐MOFs and halloysite nanotubes (HNTs) were blended and added to silicone rubber foams (SiFs). The mechanical properties and flame retardancy of the composites were tested and analyzed using universal tensile tester, limiting oxygen index (LOI), vertical combustion tester, cone calorimeter, TG, SEM, EDS, and FTIR. The results show that Al‐MOFs synthesized by the solvothermal method have high crystallinity and purity. Compared with pure SiFs, the LOI of SiFs with 2 wt% MIL‐53(Al) and 2 wt% HNTs increased to 29.4%, while total heat release and total smoke release decreased by 36.9% and 32.4%. The flame retardant mechanism of the composites is mainly reflected in the condensed phase. MIL‐53(Al) and HNTs can synergistically promote the formation of a dense carbon layer, blocking heat and oxygen from entering the SiFs matrix. [ABSTRACT FROM AUTHOR]

In this research, halloysite nanotubes (HNTs) modified with polydopamine and phosphotungstic acid (PWA) were used to enhance the performance of the SPEEK-based proton exchange membrane (PEM). The PEEK sulfonation process was carried out through an advanced method to obtain a higher degree of sulfonation. To provide more proton-transferring pathways in the structure of the membrane, polydopamine and PWA were coated on the outer and inner/outer surfaces of HNTs (named as DHNT and PHNT), respectively. Coating PWA on the inner surface of HNTs through the application of vacuum was a novel approach in this study that was validated by Fourier transform infrared spectroscopy (FTIR) analysis. The high acidity of PWA, the presence of hydrophilic groups in the structure of polydopamine, and the tubular structure of HNTs improved the water uptake and proton conductivity of the modified PEMs. Accordingly, the DHNT- and PHNT-modified PEMs exhibited 33% and 83% higher water uptake compared to the neat SPEEK membrane. Proton conductivities of the membranes modified with DHNT and PHNT at 60 °C and 100% relative humidity were 63% and 86% higher than that of the neat SPEEK membrane, respectively. In addition, the membrane performance in MFC showed that the cell equipped with the PHNT-modified membrane achieved 7.6% greater maximum power than the commercial Nafion117 membrane. [ABSTRACT FROM AUTHOR]