Surface Of Halloysite Nanotubes Research Articles

Novel rod-like bifunctional nanocomposites: Enhanced NIR-IIb luminescence and microwave heat conversion property by local surface plasmon resonance effect and space-dielectric confinement effect

A novel halloysite nanotubes(HNT)@WO3-x@GdF3:Yb3+,Er3+ rod-like bi-functional nanocomposites with strong NIR-IIb (near-infrared second window 1500–1700 nm) luminescent and microwave heat conversion property was obtained by introducing the local surface plasmon resonance effects (LSPR) and the space-dielectric confinement effect. The novel nanocomposites were characterized in terms of the structure, morphology and property. The result of XRD, SEM and TEM analysis showed that WO3-x and GdF3:Yb3+,Er3+ nanocrystals were successfully deposited on the surface of HNT. In comparison to GdF3:Yb3+,Er3+, the NIR-IIb emission intensity of HNT@WO3-x@GdF3:Yb3+,Er3+ rod-like nanocomposites is significantly enhanced (8.4 times) and improved fluorescence lifetime (0.1591us to 0.1725 us) at 808 nm excitation. This results suggested that LSPR of WO3-x can regulate the NIR-IIb luminescent properties of HNT@WO3-x@GdF3:Yb3+,Er3+ nanocomposites. And HNT@WO3-x@GdF3:Yb3+,Er3+ rod-like nanocomposites had stronger microwave thermal conversion property based on space confinement effect and dielectric confinement effect. The HNT@WO3-x@GdF3:Yb3+,Er3+ rod-like nanocomposites successfully combined NIR-IIb luminescent and microwave heat conversion property to one, in addition, halloysite nanotubes be endowed to NIR-IIb luminescent properties and microwave heat conversion property. This study provides a new idea and method for the preparation of new bi-functional nanocomposites.

Sequential super-assembled nanomotor adsorbents for NIR light-Powered blood lead removal

Hemoperfusion is a common treatment for lead poisoning, where hemoperfusion adsorbents are used to remove lead ions from blood. However, traditional hemoperfusion adsorbents often suffer from limited efficiency and poor biocompatibility, reducing their effectiveness for human use. To address these limitations, we developed a novel photothermal nanomotor adsorbent through a controllable sequential super-assembly strategy. Gold nanoparticles (Au NPs) were incorporated into the nanochannels of halloysite nanotubes (HNTs), followed by modification of the outer HNT surface with polydopamine (PDA) and 2,3-dimercaptosuccinic acid (DMSA), forming Au@HNTs@PDA-DMSA. This nanomotor adsorbent leverages the photothermal properties of Au NPs to achieve self-propulsion via thermophoresis under near-infrared (NIR) light irradiation. The performance of this nanomotor was evaluated for Pb(II) removal in both aqueous solutions and human blood samples, reaching adsorption equilibrium within 20 min and a maximum capacity of 45.980 mg/g. The adsorption kinetics followed a pseudo-second-order model with a high fitting coefficient (R2 = 0.999), and the Langmuir model fit better than the Freundlich model, indicating monolayer adsorption. Notably, when driven by 808 nm NIR light at 1.0 W cm−2, the Au@HNTs@PDA-DMSA nanomotors showed a significantly enhanced adsorption capacity of 151.769 mg/g, improving blood lead removal efficiency by 1.80 times compared to non-irradiated conditions. Furthermore, the addition of sulfhydryl and carboxyl groups from DMSA provided more active sites, leading to a 9.76-fold increase in lead removal compared to passive adsorbents using HNTs. In vitro tests confirmed the excellent biocompatibility and biosafety of the nanomotor adsorbent, achieving a blood lead removal rate of 91.25 %. This advancement overcomes the limitations of traditional lead adsorbents, offering a promising solution for more effective lead detoxification in clinical and environmental settings.

Facile generation of unsaturated-coordinated and atomically-dispersed hafnium active sites for the highly efficient catalytic transfer hydrogenation of levulinic acid

The sluggish kinetic of the hydrogen transfer reaction pose a significant challenge in developing efficient catalytic transfer hydrogenation (CTH) system for upgrading biomass-derived platform molecules. In this contribution, for the first time, hafnium (Hf) species have been found to coordinate with the hydroxyl groups on halloysite nanotubes surface to construct a single-atom Hf catalyst (Hf@HNTs) with unsaturated-coordinated structure at room temperature. Especially, the Hf(1.7)@HNTs delivered an impressive catalytic performance for the CTH of levulinic acid (LvA) to gamma-valerolactone (GVL) with high turn-over frequency (TOF) of 43.1 h−1 at 160 °C, considerably exceeding that of coordination-saturated HfO2 and state-of-art Hf-based catalysts. Experimental and density functional theory (DFT) studies revealed that Hf(1.7)@HNTs possessed unsaturated-coordinated and atomically-dispersed Hf-O Lewis acid-base pairs, which favored the adsorption and activation of LvA. Moreover, DFT calculations explicitly demonstrated that the energy barriers for the hydrogen transfer between the LvA and hydrogen donor were significantly reduced on the Hf(1.7)@HNTs than that of HfO2.

Enhanced anti-biochemical fouling properties of the polyacrylonitrile membranes assisted by the d-amino acid surface-modified halloysite nanotubes

Membrane fouling has always been one of the key problems to be solved in the liquid–liquid separation process of biomacromolecules, proteins, bacteria, etc. Here, halloysite nanotubes (HNTs) surface-modified with D-Amino acid (D-Aa) is synthesized in one step and introduced into the polyacrylonitrile (PAN) ultrafiltration membrane matrix to obtain a PAN mixed matrix membrane (MMM). D-Aas with three different R groups are selected to modify the HNTs. The results show that the carboxyl and amino groups of the D-Aa molecules interact with the surface of HNTs through hydrogen bonds, while the R groups are oriented towards the outside of the tube, thereby becoming the main factor affecting the surface chemical structure of the HNTs. Therefore, due to the low polarity of isobutyl and the good affinity with PAN and DMAc molecules, D-leucine-modified halloysite nanotubes (D-Leu@HNTs) can be evenly dispersed in the PAN membrane matrix and segregate to the membrane top-surface and pore wall during the non-solvent induced phase separation (NIPS) process with the solvent exchange between water and DMAc, thereby significantly improving the pore structure and hydrophilicity of the polyacrylonitrile membrane, and ultimately giving the PAN/D-Leu membrane ultra-high pure water permeability (PWP) of 1334 L·m−2·h−1·bar−1, rejection of 100 %, and excellent anti-biochemical fouling performances. The prepared PAN/D-Leu membrane maintains stable and efficient filtration performances in the 300-hour cross-flow experiment, and the membrane after testing still has excellent anti-biofilm fouling performance, showing a promising industrial application prospect.

Exploration of halloysite-based nest-like microspheres as a multifunctional reinforcement of epoxy resin

In this study, nest-like microspheres were facilely prepared using halloysite nanotubes (HNTs) as starting material, based on the dehydration reaction between hydroxy groups on the surface of HNTs. The nest-like structure of the obtained HNTs-based nest-like microspheres (HNTs-NMs) is demonstrated by SEM observations. HNTs-NMs exhibit desirable dispersibility in water and commonly used polymer matrices, which can be used as reinforcing agents in preparing epoxy resin composite in situ. The incorporation of HNTs-NMs into the epoxy resin gives rise to higher properties in stretching, impact, and toughness than both epoxy resin and equivalent HNTs-reinforced epoxy resin. The development of HNTs as nest-like microspheres affords the reinforcing agent with simultaneously enhanced mechanical properties for the obtained polymer composites. Furthermore, Mo-anchored HNTs-NMs (Mo-HNTs-NMs) were synthesized and a desirable microwave absorption ability is obtained. The optimal reflection loss is −25.47 dB at 16.91 GHz. When used as reinforcing agent, Mo-HNTs-NMs show a near-equal effect as compared to HNTs-NMs.

Catalytic Nano-Gold Immobilized on the Inner Surfaces of Halloysite Nanotubes for Selective Reduction of Nitroaromatics

Catalytic Nano-Gold Immobilized on the Inner Surfaces of Halloysite Nanotubes for Selective Reduction of Nitroaromatics

The Effect of Silanized Halloysite Nanotubes on the Structure of Polyethylene-Based Composite.

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.

An ammonia-sensitive fluorescence sensor based on polyvinyl alcohol-graphene quantum dots/halloysite nanotubes hybrid film for monitoring fish freshness

A fluorescent hybrid film composed of nitrogen-doped graphene quantum dots (N-GQDs) loaded on halloysite nanotubes (HNTs) (N-GQDs/HNTs nanocomposite) as a sensitive element and polyvinyl alcohol (PVA) as a film-forming matrix was designed for freshness detection. The PVA-N-GQDs/HNTs hybrid film exhibited significantly enhanced fluorescence attributed to the loading of N-GQDs onto the surface of HNTs through electrostatic interactions and hydrogen bonding, effectively reducing their aggregation. The fluorescence of the hybrid film could be quenched by ammonia via photoinduced electron transfer (PET), with good linearity in the range of 20 ppm to 500 ppm ammonia and a limit of detection (LOD) of 0.63 ppm. In addition, the hybrid film was applied to monitor the freshness of seawater fish and freshwater fish stored at refrigeration and room temperature to evaluate the practicality of this approach. The developed hybrid film showed promise for nondestructive and on-site monitoring of fish spoilage.

The fabrication of organic-inorganic hybrid structure towards high mechanical property and improved flame retardancy

In order to design UPR composites with high mechanical property and improved flame retardancy, an organic-inorganic hybrid flame retardant (DA-Si-HNT) was fabricated by grafting silane coupling agent (KH560) and the phosphorus-nitrogen containing structure (DOPA-A, the production of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and adenine) on the surface of halloysite nanotube (HNTs). The UPR/DA-Si-HNT15 composites exhibited significant improvements in tensile strength, tensile modulus, and flexural strength, with respective increases of 65.6 %, 140.6 %, and 80.2 % compared to neat UPR. These enhancements can be attributed to the enhanced compatibility and interfacial force between the flame retardants and the polymer matrix. Meanwhile, it passed the UL-94 V-0 rating at a limiting oxygen index (LOI) value of 34.5 %. The peak of heat release rate (PHRR) and total heat release (THR) decreased by 49.5 % and 43.5 % comparing to that of UPR, indicating a sharp decline in the heat hazard. Moreover, an obvious catalytic carbonization effect in the condensed phase accompanied with moderate gas-phase effect jointly improved flame retardancy of the UPR/DA-Si-HNT15 composites.

Metalized Plastic Current Collectors Incorporated with Halloysite Nanotubes toward Highly Safe Lithium‐Ion Batteries

AbstractMetalized 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.

Study on dry desulfurization performance of modified HNTs

The production characteristics of coking industry determine that the coke quenching process has the characteristics of complex pollutant composition, high purification difficulty and serious environmental pollution. SO2 is one of the main pollutants in coke dry quenching tail gas, which is easy to cause serious harm. Dry desulfurization process is the use of particles or powder desulfurizer to remove SO2. The hydroxyl groups on the surface of Halloysite nanotubes make the active components of catalytic reaction fixed on the nano-scale surface or in the lumen, which can produce more selective and active catalytic materials with good catalytic performance. In this study, HNTs were modified by molten salt etching method. The functionalized halloysite and chitosan were cured by chemical precipitation method to prepare halloysite chitosan nanospheres desulfurizer, and its application performance and reaction mechanism in SO2 removal were explored.

Charge-Selective Photocatalytic Degradation of Organic Dyes Driven by Naturally Occurring Halloysite Nanotubes

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.

Bio-derived polyphosphazene modified halloysite nanotubes as eco-friendly flame retardants to significantly reduce smoke release and enhance the fire safety of epoxy resin

At present, designing efficient bio-based flame retardants for epoxy resin (EP) and exploring low-toxicity and sustainable flame retardant strategies is still a great challenge. In this work, a novel bio-based hybrid flame retardant was successfully prepared by constructing a resveratrol-based cyclic cross-linked polyphosphazene (PPZ) shell on the surface of halloysite nanotube (HNT). The enhancement effects of HNT@PPZ on the fire safety of EP composites were investigated by thermal degradation, simulated fire performance (cone calorimeter test), gas-phase product analysis, and condensed-phase char residue analysis. Compared to pure EP, he total heat release (THR), total smoke production (TSP) and the average yield of carbon monoxide (Av-COY) of EP/3HNT@PPZ were reduced by 47.8 %, 46.5 % and 48.8 % respectively. Furthermore, the EP composites containing HNT@PPZ had a stable flame retardancy even after 6 months of natural aging. It was found the barrier effect of HNT@PPZ in condensed phase was further strengthened by the formation of new product aluminum phosphate, which formed a multiple protective char layer. Additionally, PPZ shell improved compatibility and dispersion of HNT in EP matrix, the mechanical properties of the composite with HNT@PPZ were improved significantly. This work proposed a feasible solution for the preparation of highly efficient bio-based flame retardants with excellent heat reduction and smoke toxicity reduction ability, which could be expected to broaden the application of biomass resources in the development of highly efficient flame retardants.

Protecting Mg-sites from hydration by embedding magnesium-aluminium layered double hydroxide in halloysite and using as pickering catalysts in Baeyer-Villiger oxidation

A facile strategy was developed via thermal treatment to get hierarchically structured magnesium-aluminium layered double hydroxide (MgAl-LDH) selectively loaded on the inner and external surfaces of halloysite nanotubes, respectively. The loaded MgAl-LDH was found to have active centers for Baeyer-Villiger (BV) oxidation that was protected from hydration by embedding in halloysite lumens. The BV oxidation of cyclohexanone was observed to have better performance by using the halloysite impregnated MgAl-LDH (MgAl-LDH@Hal) as catalysts than that of external surface modified MgAl-LDH (MgAl-LDH@Hal600). A conversion 57.0% of cyclohexanone was achieved, and the yield of ε-caprolactone was 22.0% when the MgAl-LDH@Hal was used as catalysts. Density Functional Theory (DFT) calculations as well as high-resolution of X-ray photoelectron spectrum (XPS) measurements revealed the charge depletion occurred in the Mg-sites of sample MgAl-LDH@Hal in comparison with MgAl-LDH@Hal600, which benefited the activation of H2O2 oxidants, and thus assisting the BV reaction. The prepared composites were able to work as phase-transfer catalysts as Pickering emulsions in oxidation of cyclohexanone.

Facile synthesis of ZnO/halloysite nanotube composite with greatly enhanced photocatalytic performance

ZnO/halloysite nanotube composites (ZH-X, X = 10, 30, 40, 50, 70), with different mass ratio of ZnO to halloysite nanotubes (HNTs), were fabricated successfully via a facile wet chemical technique in anhydrous ethanol under a mild reaction condition. ZnO nanoparticles about 9 nm in size were inhibited from agglomeration and loaded homogeneously on the surface of HNTs. The microstructure, specific surface area, light absorption ability, photocatalytic performance, etc. of the ZH-X composites varied with the mass ratio of ZnO to HNTs. All ZH-X composites displayed better photocatalytic performance than pure ZnO sample did. With the increasing of ZnO content, the photocatalytic activity of ZH-X composite toward degrading methylene blue (MB) solution strengthened gradually and reached the maximum by ZH-40 composite (with ZnO content of 28.57 wt%), then decreased step by step. ZH-40 (0.05 g) removed 99.88% of MB (100 mL, 15 mg/L) after adsorption in dark and then photocatalytic degradation for 60 min, and whose photocatalytic reaction rate constant was 5.73 times that of pure ZnO. The enhanced photocatalytic efficiency of ZH-40 composite was attributed to the interfacial effect of ZnO and HNTs as well as the dispersed ZnO nanoparticles, which maintained the adsorption ability of HNTs and improved the separation and migration of photo-generated electron and hole pairs. This work provides a feasible method for loading photocatalyst on clay mineral to realize efficient photocatalysis.

Fabrication and characterization of Halloysite–Fe3O4–Ag nanocomposite as efficient catalyst for metronidazole degradation by using sodium borohydride: Artificial neural network modeling

In this work, halloysite–Fe3O4–Ag nanocomposite produced by doping Fe3O4 and Ag nanoparticles on the surface of halloysite nanotube after activation with HCl by co-precipitation method was used as a catalyst for the catalytic degradation of metronidazole antibiotic with sodium borohydride. The physical and chemical structure of synthesized nanocomposite were characterized by pHpzc, FTIR, XRD, SEM/EDX and TGA. The degradation process of metronidazole antibiotic with sodium borohydride in the presence of nanocomposite catalyst was investigated. According to this, metronidazole removal efficiency was determined as %93.1 (as 0.069 in terms of Ct/C0) at the end of 120-min contact time under determined optimum conditions (pH 7, 10 mM NaBH4 concentration, 2 g/L catalyst dosage, 25 °C temperature) for 30 ppm metronidazole solution. In the pH range in which the process is applied, metronidazole is in anionic form in solution. The used nanocomposite was efficiently recycled and it was determined that it could be reused at least 6 times as a catalyst. Moreover, the process was modeled with Artificial Neural Networks approach. Finally, it was revealed with HPLC analysis that metronidazole was converted into different products as a result of applied process.

Design of Etched- and Functionalized-Halloysite/Meloxicam Hybrids: A Tool for Enhancing Drug Solubility and Dissolution Rate.

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.

Quantitative XPS analysis of amine-terminated dendritic functionalized halloysite nanotubes decorated on PAN nanofibrous membrane and adsorption/filtration of Cr(VI)

Quantitative XPS analysis of the active functional groups on the surface of nanofiber membranes is an important issue for evaluating the potential efficiency of the membranes in removing heavy metals from aqueous solutions. This research is developing a novel composite nanofiber for accessibility adsorption groups on the surface of the electrospun membrane for effective removal of Cr(VI). For this purpose, three generations (G1, G2, and G3) of poly(amidoamine) dendrimers (PAMAM) were grafted onto the surface of halloysite nanotubes (HNTs). Functionalized HNTs (F-HNTs) were decorated on the surface of polyacrylonitrile (PAN) nanofiber layers in different ratios by simultaneous electrospinning and electrospraying techniques. The results showed that the decoration with F-HNTs made the surface of the membranes superhydrophilic. The removal efficiency of the optimal sample with 10 % third-generation F-HNTs (PAN/HNTs-G3-10 %) reached 96 % within 5 min. The mechanism for the removal of Cr(VI) ions in the PAN/HNTs-G3-10 % membrane was electrostatic interaction, chelation, and reduction. X-ray photoelectron spectrometer (XPS) analysis was used to characterize the quantitative and qualitative correlation dependencies between the removal of Cr(VI) and the amine functional groups of different generations decorated onto the electrospun layer. Quantitative analysis of the amine-terminated dendritic groups has revealed that the percentage of Cr(VI) removal is proportional to the number of terminal amine groups. Furthermore, PAN/HNTs-G2 and PAN/HNTs-G3 composite nanofiber membranes showed significantly lower leachability of nanoparticles and higher mechanical strength compared to other membranes due to the formation of ionic bonds between the amine-terminated dendritic of HNTs-G2 and HNTs-G3 and the cyanide groups of PAN. Effects of competing heavy metal ions on Cr(VI) adsorption follow the order of Zn(II) > Cu(II) > Ni(II).

Towards promoting wound healing: A near-infrared light-triggered persistently antibacterial, synergistically hemostatic nanoarchitecture-integrated chitosan hydrogel

The skin, the primary barrier of the body, is inevitably broken. However, the development of materials that facilitate wound healing with sustained antimicrobial, hemostatic, and biocompatible properties remains a formidable challenge. In this article, we prepared a photopolymerizable composite hydrogel consisting of a hydrogel matrix, a hemostatic/antibacterial agent, and a photothermal therapy agent. The photopolymerizable hydrogel matrix was prepared by grafting the photoinitiator and polymerizable active monomer onto the chitosan chain segment, which exhibits excellent biocompatibility. Furthermore, linalool is adsorbed on the surface of halloysite nanotubes (HNTs) to form a hemostatic and antibacterial. Meanwhile, dopamine is employed as a coating material for hollow glass microsphere (HGM), which enables them to function as photothermal therapy agents. Upon exposure to near-infrared radiation, the PHA hydrogel releases linalool molecules from the surface of the HNTs, which diffuse into the hydrogel matrix, resulting in a sustained antimicrobial effect. At the same time, rapid curing of the photopolymerizable hydrogel under UV light forms a physical barrier that synergistically enhances the hemostatic properties of the HNTs. From the above, the results pave the way to develop a potential hemostatic antimicrobial dressing for clinical use in wound healing.

An integrated experimental and theoretical approach to probe Cr(vi) uptake using decorated halloysite nanotubes for efficient water treatment.

Halloysite nanotubes (HNTs) were surface functionalized using four distinct chemical moieties (amidoxime, hydrazone, ethylenediamine (EDA), and diethylenetriamine (DETA)), producing modified HNTs (H1-H4) capable of binding with Cr(vi) ions. Advanced techniques like FTIR, XRD, SEM, and EDX provided evidence of the successful functionalization of these HNTs. Notably, the functionalization occurred on the surface of HNTs, rather than within the interlayer or lumen. These decorated HNTs were effective in capturing Cr(vi) ions at optimized sorption parameters, with adsorption rates ranging between 58-94%, as confirmed by atomic absorption spectroscopy (AAS). The mechanism of adsorption was further scrutinized through the Freundlich and Langmuir isotherms. Langmuir isotherms revealed the nearest fit to the data suggesting the monolayer adsorption of Cr(vi) ions onto the nanotubes, indicating a favorable adsorption process. It was hypothesized that Cr(vi) ions are primarily attracted to the amine groups on the modified nanotubes. Quantum chemical calculations further revealed that HNTs functionalized with hydrazone structures (H2) demonstrated a higher affinity (interaction energy -26.33 kcal mol-1) for the Cr(vi) ions. This can be explained by the formation of stronger hydrogen bonds with the NH moieties of the hydrazone moiety, than those established by the OH of oxime (H1) and longer amine chains (H3 and H4), respectively. Overall, the findings suggest that these decorated HNTs could serve as an effective and cost-efficient solution for treating water pollution.