Modified Halloysite Nanotubes Research Articles

Flame retardant polyurethane acrylate solid polymer electrolyte based on the synergistic effect of modified halloysite nanotubes for safe lithium batteries

The practical application of polyurethane acrylate solid electrolytes is restricted by their flammability and inadequate of ion transportation performance. Herein, a novel flame retardant solid polymer electrolyte membrane was successfully designed through UV light curing phosphorus-containing polyurethane acrylate prepolymer, modified halloysite nanotubes and lithium salt. The FR-SPE1 electrolyte mainly composed of flame retardant polyurethane acrylate (FR-PUA) prepolymer, 20 wt% lithium bis-(trifluoromethanesulfonyl)imide) (LiTFSI) along with 5 wt% acid modified halloysite nanotubes(A-HNTs), which possesses excellent P-Al-Si synergistic flame retardancy with the limiting oxygen index (LOI) value of 39.2%, and the vertical burning test can reach the V-0 level of UL 94 standard. Meanwhile, FR-SPE1 electrolyte exhibits strong mechanical strength and electrochemical stability, which extends the electrochemical window to 4.88 V (vs. Li+/Li). Interestingly, A-HNTs can also effectively enhance the dissociation degree of lithium salts in polymers, which is conducive to improve the lithium ion transport performance. Moreover, the cell fabricated by lithium iron phosphate (LiFePO4), FR-SPE1 and Li anodes evinces benign cycling performance (156.6 mAhg−1, 0.2C) and coulombic efficiency (99.06%) after 160 cycles at 70 °C. Thus, FR-SPE1 is argued to provide an effective approach for more broadly enhancing lithium battery safety and performance.

Recent progress in the preparation, characterization, and applications of modified halloysite nanotubes as adsorbents for wastewater treatment

Recent progress in the preparation, characterization, and applications of modified halloysite nanotubes as adsorbents for wastewater treatment

Polymeric smart coatings containing modified capped halloysite nanotubes for corrosion protection of carbon steel

A newly designed smart self-healing epoxy coating system comprised of modified halloysite nanotubes (HNTs) having capping is proposed for corrosion protection of steel. In the first step, HNTs were loaded with 8-hydroxyquinoline (8HQ), used as a corrosion inhibitor. Then the HNTs were sealed/capped using cobalt (II), aiming for an efficient and controlled release of the loaded inhibitor. The smart coatings were developed by reinforcing loaded HNTs into the epoxy matrix. The structural, thermal, mechanical, and electrochemical properties of capped modified HNTs and smart coatings were studied using various techniques. UV–Vis analysis depicted that the capping of the metal-inhibitor complex was decomposed at acidic pH resulting in a controlled release of the loaded inhibitor into HNTs. Electrochemical impedance spectroscopic (EIS) analysis of blank and smart coatings demonstrated that the low-frequency impedance modulus of smart coatings is 109 Ω.cm2 for 20 days compared to blank coatings (105 Ω.cm2), reflecting their excellent corrosion inhibition performance. The superior corrosion protection properties of these smart coatings can be ascribed to the controlled and efficient release of the loaded inhibitor from the capped HNTs. Finally, X-ray photoelectron spectroscopy (XPS) analysis of the steel substrate after the corrosion analysis revealed the adsorption of 8HQ on the steel surface, confirming the formation of iron complex due to the release of loaded inhibitor. This work demonstrated the adeptness of 8HQ in mitigating the corrosion due to the controlled and effective release of the inhibitor from capped HNTs because of dissociation of the metal-inhibitor complex (Co-8HQ).Graphical abstract

Functionalized Halloysite Nanotubes as Potential Drug Carriers

The aim of the work was to examine the possibility of using modified halloysite nanotubes as a gentamicin carrier and to determine the usefulness of the modification in terms of the effect on the amount of the drug attached, its release time, but also on the biocidal properties of the carriers. In order to fully examine the halloysite in terms of the possibility of gentamicin incorporating, a number of modifications of the native halloysite were carried out prior to gentamicin intercalation with the use of sodium alkali, sulfuric and phosphoric acids, curcumin and the process of delamination of nanotubes (expanded halloysite) with ammonium persulfate in sulfuric acid. Gentamicin was added to unmodified and modified halloysite in an amount corresponding to the cation exchange capacity of pure halloysite from the Polish Dunino deposit, which was the reference sample for all modified carriers. The obtained materials were tested to determine the effect of surface modification and their interaction with the introduced antibiotic on the biological activity of the carrier, kinetics of drug release, as well as on the antibacterial activity against Escherichia coli Gram-negative bacteria (reference strain). For all materials, structural changes were examined using infrared spectroscopy (FTIR) and X-ray diffraction (XRD); thermal differential scanning calorimetry with thermogravimetric analysis (DSC/TG) was performed as well. The samples were also observed for morphological changes after modification and drug activation by transmission electron microscopy (TEM). The conducted tests clearly show that all samples of halloysite intercalated with gentamicin showed high antibacterial activity, with the highest antibacterial activity for the sample modified with sodium hydroxide and intercalated with the drug. It was found that the type of halloysite surface modification has a significant effect on the amount of gentamicin intercalated and then released into the surrounding environment but does not significantly affect its ability to further influence drug release over time. The highest amount of drug released among all intercalated samples was recorded for halloysite modified with ammonium persulfate (real loading efficiency above 11%), for which high antibacterial activity was found after surface modification, before drug intercalation. It is also worth noting that intrinsic antibacterial activity was found for non-drug-intercalated materials after surface functionalization with phosphoric acid (V) and ammonium persulfate in the presence of sulfuric acid (V).

Natural organic-inorganic hybrid structure enabled green biomass adhesive with desirable strength, toughness and mildew resistance

Plant based proteins are green, sustainable, and renewable materials that show the potential to replace traditional formaldehyde resin. High performance plywood adhesives exhibit high water resistance, strength, toughness, and desirable mildew resistance. Adding petrochemical-based crosslinkers is not economically viable or environmentally benign; this chemical crosslinking strategy makes the imparted high strength and toughness less attractive. Herein, a green approach based on natural organic-inorganic hybrid structure enhancement is proposed. The design of soybean meal-dialdehyde chitosan-amine modified halloysite nanotubes (SM-DACS-HNTs@N) adhesive with desirable strength and toughness enhanced by covalent bonding (Schiff base) crosslinking and toughened by surface-modified nanofillers is demonstrated. Consequently, the prepared adhesive showed a wet shear strength of 1.53 MPa and work of debonding of 389.7 mJ, which increased by 146.8 % and 276.5 %, respectively, due to the cross-linking effect of organic DACS and toughening effect of inorganic HNTs@N. The introduction of DACS and Schiff base generation enhanced the antimicrobial property of the adhesive and increased the mold resistance of the adhesive and plywood. In addition, the adhesive has good economic benefits. This research creates new opportunities for developing biomass composites with desirable performance.

Phase change material microcapsules with DOPO/Cu modified halloysite nanotubes for thermal controlling of buildings: Thermophysical properties, flame retardant performance and thermal comfort levels

Although the microencapsulated phase change material (MPCM) with organic core-shell structure is an effective means to encapsulate phase change material (PCM), it has the defects of low thermal conductivity and flammability. Herein, the flame retardant halloysite nanotubes (c-HNTs) doped by 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and Cu nanoparticles were successfully inserted in the MPCM to form a highway to heat transfer. The related examination and surface morphology showed that the DOPO structure anchored by Cu nanoparticles was grafted on the surface of halloysite nanotubes (HNTs) and the c-HNTs were successfully embedded in MPCM. The thermogravimetric analysis (TGA) proved that c-MPCM has the best thermal stability when compared to other samples, which is caused by the presence of c-HNTs. The differential scanning calorimetry (DSC) test indicated that MPCM delays the heat transfer to the capric acid while the HNTs improve this situation as thermal conduction channels. Then, the MPCM samples were added to the epoxy resin (EP). In the cone calorimetry test, we found that the heat and smoke release rate of EP composite is obviously reduced. Finally, the temperature control ability test of MPCM demonstrated that the EP composite with c-HNTs has the minimum temperature fluctuation. These properties will greatly stimulate the application of c-MPCM in insulation materials.

Synergistically Enhanced Oxygen Evolution Catalysis with Surface Modified Halloysite Nanotube

Synergistically increased oxygen evolution reaction (OER) of manganese oxide (MnO<sub>2</sub>) catalyst is introduced with surface-modified halloysite nanotube (Fe<sub>3</sub>O<sub>4</sub>-HNTs) structure. The flake shaped MnO<sub>2</sub> catalyst is attached on the nanotube template (Fe<sub>3</sub>O<sub>4</sub>-HNTs) by series of wet chemical and hydrothermal method. The strong interaction between MnO<sub>2</sub> and Fe<sub>3</sub>O<sub>4</sub>-HNTs maximized active surface area and inter-connectivity for festinate charge transfer reaction for OER. The synergistical effect between Fe<sub>3</sub>O<sub>4</sub> layer and MnO<sub>2</sub> catalyst enhance the Mn<sup>3+</sup>/Mn<sup>4+</sup> ratio by partial replacement of Mn ions with Fe. The relatively increased Mn<sup>3+/</sup>Mn<sup>4+</sup> ratio on MnO<sub>2</sub>@FHNTs induced <italic>σ</italic><italic><sup>*</sup></italic> orbital (e<sub>g</sub>) occupation close to single electron, improving the OER performances. The MnO<sub>2</sub>@FHNTs catalyst exhibited the reduced overpotential of 0.42 V (E <italic>vs</italic>. RHE) at 10 mA/cm<sup>2</sup> and Tafel slope of (99 mV/dec), compared with that of MnO<sub>2</sub> with unmodified HNTs (0.65 V, 219 mV/dec) and pristine MnO<sub>2</sub> (0.53 V, 205 mV/dec). The present study provides simple and innovative method to fabricate nano fiberized OER catalyst for a broad application of energy conversion and storage systems.

Modified halloysite nanotubes decorated with Ceria for synergistic corrosion inhibition of Polyolefin based smart composite coatings

The deteriorating effect of corrosion can be controlled by applying suitable polymeric-based coatings. In this work, polyolefin based smart composite coatings containing modified halloysite nanotubes decorated with ceria particles were investigated to analyze their anti-corrosion behavior. For this purpose, halloysite nanotubes (Hals) were utilized as nanocarriers which were loaded with sodium dodecyl sulfate (SDS) as a corrosion inhibitor via overnight stirring and vacuum cycling method. The loaded Hals were then modified/decorated with cerium oxide (CeO2) particles by reacting cerium nitrate (Ce (NO3)3.6H2O) and sodium hydroxide (NaOH) which resulted in the formation of CeO2@HAL/SDS. The synthesized modified particles (CeO2@HAL/SDS) were characterized by energy-dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM), Fourier-Transform Infrared Spectrometer (FTIR), Thermogravimetric analysis (TGA), and differential thermal gravimetric analysis (DTA), X-ray diffraction analysis (XRD) and UV–vis spectroscopic analysis. TGA analysis results demonstrated that about 32% (w/w) of SDS has been loaded into Hal, and 47% (w/w) of CeO2 has been immobilized on the surface of Hal. UV–Vis analysis results demonstrated the pH-sensitive and time-dependent release behavior of synthesized particles. Furthermore, the modified CeO2@HAL/SDS particles (1 wt%) were reinforced into the polyolefin-based matrix, coated on a polished steel substrate and their electrochemical properties were investigated. The electrochemical impedance spectroscopy (EIS) analysis confirms the promising improvement in the corrosion inhibition performance of polyolefin coatings modified with CeO2@HAL/SDS particles when compared to the polyolefin composite coatings modified with HAL/SDS due to the synergistic corrosion inhibition performance of Ce(OH)3 and Fe-SDS formation at the cathodic and anodic region of steel.

In-situ incorporation of halloysite nanotubes with 2D zeolitic imidazolate framework-L based membrane for dye/salt separation

Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks (ZIF-L) nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability, but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application. Herein, we synthesized mHNTs (modified halloysite nanotubes)/ZIF-L nanocomposites on modified mHNTs by in situ growth method. Interestingly, due to the different size of mHNTs and ZIF-L, mHNTs were packed in ZIF-L nanosheets. The hollow mHNTs provided additional transport channels for water molecules, and the accumulation of the ZIF-L nanosheets was decreased after assembling mHNTs/ZIF-L nanocomposites into membrane by filtration. The prepared mHNTs/ZIF-L membrane presented high permeate flux (59.6 L·m−2·h−1), which is 2–4 times of the ZIF-L membranes (14.8 L·m−2·h−1). Moreover, mHNTs/ZIF-L membranes are intrinsically antimicrobial, which exhibit extremely high bacterial resistance. We provide a controllable strategy to improve 2D ZIF-L assembles, and develops novel membranes using 2D package structure as building units.

Superhydrophobic and superoleophiclic natural rubber latex foam coated by hexadecyltrimethoxysilane modified halloysite nanotube for oil/water separation

In this research, we introduce a facile synthesis of the superhydrophobic natural rubber latex foam (NRLF), sponge-NRLF materials with a high oil-sorption capacity. The superhydrophobic sponge-NRLF was prepared by decorating the halloysite nanotubes (HNTS), which are chemically modified by n-hexadecyltrimethoxysilane (HDTMS) on the surface. The effects of HDTMS@HNTs loading and vulcanization systems towards the superhydrophobic and superhydrophilic properties of the NRLF were investigated. It was found that NRLF vulcanized by conventional vulcanization system (CV) and coated with 6 wt% HDTMS@HNTs showed favorable oil/water selectivity with excellent water repellence with a contact angle of 151°. The modified NRLF showed excellent performance toward gasoline 95 with high sorption capacity, achieving up to 10 times of its own weight for a wide range of oils. Oil sorption capacity tended to decline with respect to increasing HDTMS@HNTs content and oil viscosity due to the reduced porosity and surface area of the modified NRLF. Interestingly, the modified NRLF exhibited excellent durability, as the sorption efficiency remained unchanged after 10 cycles. Moreover, their fire retardant was also improved. • Facile preparation of superhydrophobic and superoleophiclic natural rubber latex foam • Natural rubber latex foam coated by hexadecyltrimethoxysilane modified halloysite nanotube • Oil adsorption capacity and oil-water selectivity of modified natural rubber latex foam

표면 개질된 Halloysite 나노튜브(mHNTs)가 EPDM/NBR 나노복합체의 기계적 물성 및 팽윤 거동에 미치는 영향

Ethylene-propylene-diene monomer/acrylonitrile-butadiene rubber (EPDM/NBR)-modified halloysite nanotubes (mHNTs) nanocomposites were prepared by two-roll mixing mill and vulcanization process. The mole percent uptake of some aromatic (toluene, xylene, benzene and mesitylene), aliphatic (n-hexane, n-heptane, n-octane and n-pentane) and chlorinated (chloroform, carbon tetrachloride and dichloromethane) solvents through mHNT filled EPDM/NBR nanocomposites has been investigated. The aim of the present work is to investigate the role of the cure characteristics, mechanical properties, abrasion resistance and swelling resistance in analysing the compatibility between rubber matrix and nanotubes and the reinforcing effect of mHNT as nanofiller in the EPDM/NBR matrix. The mole percent uptake of organic solvents via membranes has been explored in detail as a function of mHNT content, type of solvent, and temperature between 23 and 60 oCelsius. The findings revealed that mHNT could reduce scorch and optimum cure time in EPDM/NBR vulcanizates, as well as play a significant role in strengthening EPDM/NBR vulcanizates. Mechanical properties and swelling resistance were investigated and were found to increase with the increase of mHNT loading. The cross-link density values indicated the improved strengthening at 8 phr mHNT filler loading. In the rubber matrix, mHNT particles form a local filler–filler network at high concentrations. As a result, the composites

Preparation and characterization of phase change material microcapsules with modified halloysite nanotube for controlling temperature in the building

Microencapsulated phase change material (mPCM) with effective heat transfer and flame retardant is highly desirable given today’s increasing energy demand. In this article, the halloysite nanotube (D-HNT) was modified by 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and then inserted into the mPCM (D-H-mPCM) successfully. The transmission electron microscope, X-ray photoelectron spectroscopy and FT-IR results showed that the DOPO is grafted in both interior and exterior walls of halloysite nanotube (HNT), and the D-HNT is successfully inserted into mPCM. According to thermogravimetric analysis tests, D-H-mPCM was the best thermally stable sample among other mPCM for the existence of HNT and DOPO. The differential scanning calorimetry tests showed that the latent heat of D-H-mPCM was 113.52 J/g, and the D-HNT embedded in the mPCM greatly contributes to the heat transfer of the PMMA shell. To detect the flame retardancy and temperature control performance of mPCM samples, D-H-mPCM was incorporated into epoxy resin (EP-D-H-mPCM). The data of the cone calorimeter test suggested the EP-D-H-mPCM exhibited the lowest peak of heat release rate (pHRR) and total heat release (THR) of 572.65 kW/m2 and 93.95 MJ/m2 respectively. Finally, the small room model test and infrared thermal imager test showed the application of D-H-mPCM in EP can regulate indoor temperature and moderate temperature fluctuation. This work provides a new methodology to improve both thermal conductivity and flame retardancy of mPCM.

In vitro evaluation of modified halloysite nanotubes with sodium alginate-reinforced PVA/PVP nanocomposite films for tissue engineering applications

In vitro evaluation of modified halloysite nanotubes with sodium alginate-reinforced PVA/PVP nanocomposite films for tissue engineering applications

Enhanced electrochemical removal of dye wastewater by PbO2 anodes using halloysite nanotubes with different surface charge properties

• A novel HNTs-CTS-PbO 2 composite anode was prepared. • New anode can effectively improve MB removal efficiency. • Degradation of methylene blue follows the pseudo-first-order reaction kinetics. • Elucidation of the degradation mechanism of methylene blue by modified electrodes. Electrode materials are the core of electrocatalytic oxidation technology. Herein, chitosan (CTS)-modified halloysite nanotubes (HNTs) were used for the first time in the doping modification of PbO 2 electrodes by electrodeposition technique, and novel HNTs-CTS-PbO 2 anodes were prepared and used for the electrochemical removal of the thiazine dye methylene blue (MB). The surface structure information, electrochemical properties and oxidation activity of the materials were systematically investigated, and possible degradation pathways of methylene blue were proposed. The results showed that after doping modification, the coating became flatter and denser, and the crystalline shape and crystalline phase of the PbO 2 electrode did not change, but the grain size was significantly reduced; moreover, the modified electrode had higher oxygen precipitation overpotential, larger reactive surface area and lower charge transfer resistance. Additionally, the decolorization degradation of MB by HNTs-CTS-PbO 2 electrode mainly adopts an indirect degradation mechanism and follows the pseudo-first-order kinetic model, which exhibits higher decolorization degradation rate. Analyzing the mechanism of the electrochemical removal of MB from the modified anode, which mainly involves the breakage of C N bonds under the action of ·OH, followed by demethylation and aromatic ring cleavage to obtain monoaromatic amines, sulfonic acids and phenolic compounds, and finally mineralized into inorganic small molecules such as CO 2 and H 2 O. The above results show that HNTs-CTS-PbO 2 anode is a promising candidate in the field of dye wastewater degradation and provide new insights for the application of HNTs.

Effective Solid Phase Extraction of Toxic Pyrrolizidine Alkaloids from Honey with Reusable Organosilyl-Sulfonated Halloysite Nanotubes

Pyrrolizidine alkaloids are plant secondary metabolites that have recently attracted attention as toxic contaminants in various foods and feeds as they are often harvested by accident. Furthermore, they prove themselves as hard to analyze due to their wide structural range and low concentration levels. However, even low concentrations show toxic behavior in the form of chronic liver diseases and possible carcinogenicity. Since sample preparation for this compound group is in need of more green and sustainable alternatives, modified halloysite nanotubes present an interesting approach. Based on the successful use of sulfonated halloysite nanotubes as inexpensive, easy-to-produce cation exchangers for solid phase extraction in our last work, this study deals with the further modification of the raw nanotubes and their performance in the solid phase extraction of pyrrolizidine alkaloids. Conducting already published syntheses of two organosilyl-sulfonated halloysite nanotubes, namely HNT-PhSO3H and HNT-MPTMS-SO3H, both materials were used as novel materials in solid phase extraction. After the optimization of the extraction protocol, extractions of aqueous pyrrolizidine alkaloid mixtures showed promising results with recoveries ranging from 78.3% to 101.3%. Therefore, spiked honey samples were extracted with an adjusted protocol. The mercaptopropyl-sulfonated halloysite nanotubes revealed satisfying loading efficiencies and recoveries. Validation was then performed, which displayed acceptable performance for the presented method. In addition, reusability studies using HNT-MPTMS-SO3H for solid phase extraction of an aqueous pyrrolizidine alkaloid mixture demonstrated excellent results over six cycles with no trend of recovery reduction or material depletion. Therefore, organosilyl-sulfonated halloysite nanotubes display a green, efficient and low-cost alternative to polymeric support in solid phase extraction of toxic pyrrolizidine alkaloids from complex honey matrix.

Mussel-inspired grafting pH-responsive brushes onto halloysite nanotubes for controlled release of doxorubicin

The development of stimuli-responsive drug nanocarriers is an increasingly important area in nanomedicine because efficient delivery of toxic drugs to targeted tissues minimizes side effects. The specific objective of this study was to synthesize and characterize a novel pH-responsive drug carrier based on halloysite nanotubes for the controlled release of the anticancer drug doxorubicin. Poly(N,N-dimethylaminoethyl methacrylate) brushes were grafted from the surface of halloysite nanotubes using the combination of mussel-inspired polydopamine surface modification and activators regenerated by electron transfer in atom transfer radical polymerization. The chemical structure and morphology of the modified halloysite nanotubes were investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermal gravimetric analysis as well as scanning and transmission electron microscopies. Dynamic light scattering and zeta potential analysis were carried out to evaluate the pH-responsivity of the functionalized halloysite nanotubes. The results of the drug loading and release study of pristine and functionalized halloysite nanotubes showed that grafting of poly(N,N-dimethylaminoethyl methacrylate) brushes on the polydopamine-modified halloysite nanotubes surface leads to a drastic increase in doxorubicin loading capacity and a highly pH-sensitive release behaviour. Less than 10 % of the loaded doxorubicin was released from poly (N,N-dimethylaminoethyl methacrylate)-grafted halloysite nanotubes at pH 7.4 after 24 h; in contrast, at pH 5.5 there was a continuous release of doxorubicin totalling 13 % in the first 30 min, i.e. lower than for the pristine halloysite nanotubes (32 %), but reaching 48 % after 24 h. Poly (N,N-dimethylaminoethyl methacrylate)-grafted halloysite nanotubes can hence be considered as a potential candidate for delivering highly toxic drug molecules to the acidic target sites.

Silver nanoparticles grafted onto tannic acid-modified halloysite clay eliminated multidrug-resistant Salmonella Typhimurium in a Caenorhabditis elegans model of intestinal infection

The prevalence of antimicrobial resistance (AMR) among pathogenic bacteria in livestock warrants alternate therapeutic strategies that are efficient in remediating zoonotic infections. Combination therapy with more than one antimicrobial with complementary action has shown possibilities to prevent or slow down AMR. The application of clay-based biomaterials could, however, resolve challenges of poor bioavailability, cytotoxicity, stability, release, and overdosing and play a significant role in formulating cost-effective therapeutics. In this study, a nanocomposite (GH-TA-Ag-NT) containing silver nanoparticles (Ag NPs) grafted onto tannic acid (TA)-modified halloysite nanotubes (hal NTs) was generated and compared with TA-stabilized Ag NPs (Ag-TA-NP) for physicochemical and antibacterial properties. The Transmission electron microscopy, Fourier transform infrared, Dynamic light scattering, and X-ray diffraction spectroscopies confirmed the synthesis of the nanocomposite. GH-TA-Ag-NT demonstrated enhanced stability and drug-bioavailability with a slow-release of Ag+ and TA. The nanocomposite showed superior antibacterial performance in comparison to Ag-TA-NP when tested against E. coli ATCC 25922, S. aureus ATCC 25923, and a multi-drug resistant (MDR) Salmonella enterica serovar Typhimurium (isolated from infected swine). The combinatorial effect was mediated through anti-efflux/anti-biofilm properties, oxidative stress, loss of bacterial membrane potential, and integrity. The toxicity and antibacterial efficiency of GH-TA-Ag-NT to remediate gastrointestinal infection were demonstrated in the S. Typhimurium infected Caenorhabditis elegans model. The nanocomposite was less toxic, reduced Salmonella colonization significantly within 24 h of exposure, and improved worm survivability. In summary, we demonstrated a unique and novel strategy to counter AMR bacteria by applying Nano-enabled Antibacterial Combination Therapy (NACT) with GH-TA-Ag-NT and thus propose its potential use as a therapeutic against zoonotic pathogens.

Facile fabrication of flame‐retardant and conductive cotton fabric via layer‐by‐layer assembly for human motion detection

AbstractFlexible piezoresistive pressure sensors have great application potential in many emerging fields such as electronic skin, artificial intelligence and human healthcare. However, most of the sensors are flammable, which will easily initiate fire hazard in case of short circuit. Herein, a flame‐retardant and conductive cotton fabric (CF) was fabricated for piezoresistive pressure sensor by layer‐by‐layer (LBL) assembly of branched polyethyleneimine (b‐PEI) modified halloysite nanotubes (HNTs), phytic acid (PA) and graphene oxide (GO) and the subsequent thermal reduction of GO. The composite coating layer endowed the obtained CF with excellent flame retardancy. The limiting oxygen index of the CF reached 32.72% and the char length after vertical burning test was only 3.8 cm, attributing to the physical barrier role of the HNTs and graphene nanosheets as well as the phosphorus‐nitrogen synergism between PA and b‐PEI. The CF‐based piezoresistive pressure sensor exhibited fast and accurate response, good signal stability and fatigue resistance (3000 loading‐unloading cycles) and was able to be applied for detecting human motions including pulse beat, pronunciation and various physical activities. The preparation method in this work is simple, and the piezoresistive pressure sensor shows great application prospect in the field of flexible electronics with high safety.

Preparation of HNTs‐d‐GO hybrid nanoparticles for gallic acid epoxy composites with improved thermal and mechanical properties

AbstractKH550 modified halloysite nanotubes (m‐HNTs) were hybridized with sulfoxide chloride acylated graphene oxide (m‐GO) to prepare hybrid nanoparticles (HNTs‐d‐GO). The microstructure and morphology analysis of HNTs‐d‐GO hybrid nanoparticles showed that the ordered lamellar structure of GO after acyl chlorination was stripped, and the organic groups on the surface of the lamellar increased. HNTs‐d‐GO hybrid nanoparticles were formed through the amidation of m‐HNTs and m‐GO. Then HNTs‐d‐GO hybrid nanoparticles were incorporated in galic acid epoxy resin to improve the thermal and mechanical properties. HNTs‐d‐GO/galic acid epoxy resin (HNTs‐d‐GO/GAER) bio‐based nanocomposites were prepared with methyl tetrahydrophthalic anhydride as curing agent. The galic acid epoxy composites with the addition of HNTs‐d‐GO exhibited significant enhancements of impact strength, tensile strength, storage modulus, and glass transition temperature. The initial thermal decomposition temperature (T5%) decreased, and the mass retention at 800°C increased, thermal stability of HNTs‐d‐GO/GAER composites were enhanced. At an optimum concentration of 0.75 wt% HNTs‐d‐GO, a simultaneous increase in strength and toughness was observed in comparison to the unfilled cured resin, the impact strength is 2.87 kJ/m2, which is 30.4% higher than pure GAER, and the tensile strength is 42.62 MPa, which is 29.2% higher than pure GAER. Compared with pure gallic acid epoxy resin, the content of HNTs‐d‐GO is 0.25 wt%, Tg increased by 28.9°C.

Hyaluronic Acid Modified Halloysite Nanotubes Decorated with ZIF-8 Nanoparticles as Dual Chemo- and Photothermal Anticancer Agents

Hyaluronic Acid Modified Halloysite Nanotubes Decorated with ZIF-8 Nanoparticles as Dual Chemo- and Photothermal Anticancer Agents