Composite Nanoparticles Research Articles

Engineering of LiTaO3 Nanoparticles by Flame Spray Pyrolysis: Understanding In Situ Li-Incorporation into the Ta2O5 Lattice.

Lithium tantalate (LiTaO3) perovskite finds wide use in pyroelectric detectors, optical waveguides and piezoelectric transducers, stemming from its good mechanical and chemical stability and optical transparency. Herein, we present a method for synthesis of LiTaO3 nanoparticles using a scalable Flame Spray Pyrolysis (FSP) technology, that allows the formation of LiTaO3 nanomaterials in a single step. Raman, XRD and TEM studies allow for comprehension of the formation mechanism of the LiTaO3 nanophases, with particular emphasis on the penetration of Li atoms into the Ta-oxide lattice. We show that, control of the High-Temperature Particle Residence Time (HTPRT) in the FSP flame, is the key-parameter that allows successful penetration of the -otherwise amorphous- Li phase into the Ta2O5 nanophase. In this way, via control of the HTPRT in the FSP process, we synthesized a series of nanostructured LiTaO3 particles of varying phase composition from {amorphous Li/Ta2O5/LiTaO3} to {pure LiTaO3, 15-25 nm}. Finally, the photophysical activity of the FSP-made LiTaO3 was validated for photocatalytic H2 production from H2O. These data are discussed in conjunction with the role of the phase composition of the LiTaO3 nanoparticles. More generally, the present work allows a better understanding of the mechanism of ABO3 perovskite formation that requires the incorporation of two cations, A and B, into the nanolattice.

Self-assembly TiO2@Silane@SiO2 core-shell as s-scheme heterojunction photocatalyst against methylene blue degradation: synthesis and mechanism insights

Pollutants are the most critical threats to the health of water resources. On this basis, fabricating a core-shell as an S-scheme heterojunction photocatalyst for the treatment of wastewater from methylene blue (MB) dye was aimed in this research. In this study, TiO2-doped silanized silica dielectric nanocomposites were synthesized as self-assembly TiO2@Silane@SiO2 heterojunction through sol-gel and solvothermal methods using tetrabutyl orthotitanate (TBOT) as precursor followed by calcination at 650 °C for 3 h. Silanization of silica nanoparticles was done at two different concentrations. The results showed that layer-by-layer synthesis (i.e. self-assembly of APTES on SiO2, precipitation of TiO2 layer on it by sol-gel technique and then calcination) was the optimum preparation method. The structural and morphological features were investigated by XRD, FTIR, BET, TGA-DTG, FE-SEM, EIS and ESR techniques. It was found that the band gap energy of nanocomposite particles reduced from 3.14 eV for the sample prepared by the solvothermal method (i.e. without APTES) to 2.91 eV (i.e. shifting the light absorption from UV to the visible region) for the sample prepared by the sol-gel layer-by-layer method. The prepared samples were used against the photo-degradation of MB. TiO2@Silane@SiO2 core-shell nanoparticles exhibited efficient photocatalytic degradation against MB with a photodegradation efficiency of 85 % under UV and 60 % under visible irradiation. Finally, the prepared nanocomposite particles were incorporated to an emulsion acrylic resin to prepare photocatalytic polymer film. The prepared films were evaluated for photocatalytic degradation of MB stain and mechanical performances. It was found that the TiO2@Silane@SiO2 nanocomposite particles that prepared by layer-by-layer method caused about 56 % improvement in hydrophobicity, 276.7 % increment in the tensile strength, 109.6 times enhancement in the modulus, 381.4 times enhancement in the toughness and 57.6 times improvement in the elongation at break of the acrylic film compared to the pure TiO2-containing acrylic film, respectively.

Novel nanoparticle composed by Ovalbumin-OSA modified pectin-rutin for improving the stability of Monascus pigments

To improve the resistance of Monascus pigments (MPs) to adverse environmental factors, a nanoparticle carrier was constructed using ovalbumin, rutin and pectin modified by octenyl succinic anhydride. According to the determination of particle size, ζ-potential and microstructure, the composite nanoparticles exhibited the "core-shell" structure. Specifically, the ovalbumin core was encapsulated by the modified pectin adsorbed with rutin. Spectroscopic analysis demonstrated that electrostatic interactions, hydrogen bonding and hydrophobic interactions between wall materials and MPs were the main driving forces to form composite nanoparticles. The stabilities of light, thermal and storage of MPs were significantly enhanced after encapsulation due to the physical barrier effect of the wall materials against external disturbances and the multiple functions of rutin, including free radical scavenging, absorption of partial UV and scatter light, and possible co-pigmentation effects with MPs. Moreover, the composite nanoparticles exhibited higher inhibition activity against pancreatic lipase and antioxidant activity compared with those of free MPs. The results provided an ideal way to develop new MPs products, which had long-lasting and stable performance during food processing and storage.

In-situ electrospinning PVB/Camellia oil/ZnO-TiO2 nanofibrous membranes with synergistic antibacterial and degradation of ethylene applied in fruit preservation

This work utilizes a handheld electrospinning device to prepare a novel nanofibrous composite membrane in situ for packaging freshness. It can realize pick-and-pack and is easy to operate. The nanofibrous membrane is based on PVB as the matrix material, adding Camellia oil (CO) and ZnO-TiO2 composite nanoparticles (ZT) as the active material. The antimicrobial property of the CO and the photocatalytic activity of the nanoparticles give the material good antimicrobial and ethylene degradation functions. Meanwhile, this nanofibrous membrane has good mechanical properties, suitable moisture permeability and good optical properties. The nanofibrous membrane are suitable for both climacteric and non- climacteric fruits. Its use as a cling film extends the shelf life of strawberries by 4 days and significantly slows the ripening of small tomatoes. Therefore, this nanofibrous membrane has great potential for application in the field of fruit preservation.

Microwave‐assisted synthesis of 1,4‐disubstituted 1,2,3‐triazole derivatives utilizing NiO/Cu2O nano‐photocatalyst

AbstractBACKGROUNDThe main characteristic features of nickel–copper‐catalyzed azide–alkyne click (Ni‐CuAAC) reactions for production of 1,2,3‐triazoles are regioselectivity and the reaction proceeding under mild conditions. The use of copper salts as catalysts often leads to challenges like contamination of the prepared triazoles. NiO/Cu2O nanocomposites (NCs) were utilized in Ni‐CuAAC reactions as heterogeneous nanocatalysts to achieve the production of some 1,4‐disubstituted 1,2,3‐triazoles in high chemical yields under microwave irradiation.RESULTSThe preparation of NiO/Cu2O NCs was performed through the coprecipitation of NiO nanoparticles on Cu2O surface. The prepared catalyst was used for catalyzing a reaction between benzoyl azides and phenylacetylene under optimized reaction conditions. The NiO/Cu2O NCs exhibited high catalytic activity compared to Cu2O nanoparticles. In addition, by utilizing ethanol–water as the solvent system under microwave irradiation, higher yields and efficient product separation were observed.CONCLUSIONThis study investigated the proficiency of NiO/Cu2O NCs as effective nanocatalysts for the selective synthesis of some 1,4‐disubstituted 1,2,3‐triazole derivatives. Employing heterogeneous nanoparticle catalysts, such as Cu2O and NiO/Cu2O, offers several advantages over homogeneous catalytic systems. These include easier catalyst separation and recovery, potential for catalyst reuse and the ability to fine‐tune the catalytic properties by modulating the nanoparticle composition and structure. © 2024 Society of Chemical Industry (SCI).

MOF-derived SnO2 nanoparticles for realization of ultrasensitive and highly selective NO2 gas sensing

Herein, SnO2 nanoparticles (NPs) were synthesized from a Sn-metal organic framework (MOF) through a hydrothermal synthesis approach for NO2 sensing studies. The expected phase, morphology and composition of the SnO2 NPs were demonstrated via different characterizations. The individual sizes of SnO2 NPs were ∼20–30 nm, and they had a high surface area (185.31 m2/g). The sensing properties were measured at various temperatures towards NO2 gas. It showed very high responses of 240.60 and 3984.98–10 and 100 ppm NO2, respectively, at 200°C. Also, it still displayed a high response of 47.11–100 ppm NO2 gas at 25°C. Enhanced response of MOF-derived SnO2 NPs gas sensor was owing to the high surface area of the SnO2 NPs, the presence of oxygen vacancies, formation of plenty of SnO2-SnO2 homojunctions and the creation of SnO/SnO2 heterojunctions. The synthesis method employed in this study led to the preparation of high surface area SnO2 NPs that can be used for preparing other metal oxides for the development of sensors.

Ni2MnAl Heusler Alloy Nanoparticles for Chemoselective Hydrogenation of Nitro Compounds

AbstractDespite immense interest for years in Heusler alloys as magnetoelastic materials, their application in heterogeneous catalysis has only recently been explored. We report the development of highly active, robust and magnetically separable Ni2MnAl Heusler alloy nanoparticles as a heterogeneous catalyst for hydrogenation of aliphatic and aromatic nitro compounds to the corresponding amines. The easily synthesizable Ni2MnAl nanoparticles are thermally and chemically robust and exhibited excellent chemoselectivity in the hydrogenation of a range of aliphatic and aromatic nitroarenes, including those bearing functional groups sensitive to reduction, such as alkene, bromo, iodo, carbonyl and cyano, yielding the respective functionalized amines in good yields. Moreover, this solid catalyst is magnetically separable from the reaction mixture and could be recycled and reused at least 10 times without any loss in catalytic activity. The mechanism of the Ni2MnAl Heusler alloy nanoparticles catalyzed nitro reduction was studied by various spectroscopy, control experiments and kinetics. Our work opens a new avenue of developing heterogeneous earth‐abundant metal catalysis for economic and environment‐friendly synthesis of fine chemicals owing to straightforward synthesis and tunable composition of Heusler alloy nanoparticles from base‐metal precursors and their diverse structure and properties in conjunction with their thermal and chemical stability, excellent chemoselectivity, magnetic separability and recyclability.

Orchestrating NK and T cells via tri-specific nano-antibodies for synergistic antitumor immunity

The functions of natural killer (NK) and T cells in innate and adaptive immunity, as well as their functions in tumor eradication, are complementary and intertwined. Here we show that utilization of multi-specific antibodies or nano-antibodies capable of simultaneously targeting both NK and T cells could be a valuable approach in cancer immunotherapy. Here, we introduce a tri-specific Nano-Antibody (Tri-NAb), generated by immobilizing three types of monoclonal antibodies (mAbs), using an optimized albumin/polyester composite nanoparticle conjugated with anti-Fc antibody. This Tri-NAb, targeting PDL1, 4-1BB, and NKG2A (or TIGIT) simultaneously, effectively binds to NK and CD8+ T cells, triggering their activation and proliferation, while facilitating their interaction with tumor cells, thereby inducing efficient tumor killing. Importantly, the antitumor efficacy of Tri-NAb is validated in multiple models, including patient-derived tumor organoids and humanized mice, highlighting the translational potential of NK and T cell co-targeting.

Biofuel cell-based self-powered immunosensor for detection of 17β-estradiol by integrating the target-induced biofuel release and biogate immunoassay.

A novel biofuel cell (BFC)-based self-powered electrochemical immunosensing platform was developed by integrating the target-induced biofuel release and biogate immunoassay for ultrasensitive 17β-estradiol (E2) detection. The carbon nanocages/gold nanoparticle composite was employed in the BFCs device as the electrode material, through which bilirubin oxidase and glucose oxidase were wired to form the biocathode and bioanode, respectively. Positively charged mesoporous silica nanoparticles (PMSN) were encapsulated with glucose molecules as biofuel and subsequently coated by the negatively charged AuNPs-labelled anti-E2 antibody (AuNPs-Ab) serving as a biogate. The biogate could be opened efficiently and the trapped glucose released once the target E2 was recognized and captured by AuNPs-Ab due to the decreased adhesion between the antigen-antibody complex and PMSN. Then, glucose oxidase oxidized the glucose to produce a large number of electrons, resulting in significantly increased open-circuit voltage (EOCV). Promisingly, the proposed BFC-based self-powered immunosensor demonstrated exceptional sensitivity for the detection of E2 in the concentration range from 1.0pgmL-1 to 10.0ngmL -1, with a detection limit of 0.32pgmL-1 (S/N = 3). Furthermore, the prepared BFC-based self-powered homogeneous immunosensor showed significant potential for implementation as a viable prototype for a mobile and an on-site bioassay system in food and environmental safety applications.

Oxidizing Role of Cu Cocatalysts in Unassisted Photocatalytic CO2 Reduction Using p-GaN/Al2O3/Au/Cu Heterostructures.

Photocatalytic CO2 reduction to CO under unassisted (unbiased) conditions was recently demonstrated using heterostructure catalysts that combine p-type GaN with plasmonic Au nanoparticles and Cu nanoparticles as cocatalysts (p-GaN/Al2O3/Au/Cu). Here, we investigate the mechanistic role of Cu in p-GaN/Al2O3/Au/Cu under unassisted photocatalytic operating conditions using Cu K-edge X-ray absorption spectroscopy and first-principles calculations. Upon exposure to gas-phase CO2 and H2O vapor reaction conditions, the composition of the Cu nanoparticles is identified as a mixture of CuI and CuII oxide, hydroxide, and carbonate compounds without metallic Cu. These composition changes, indicating oxidative conditions, are rationalized by bulk Pourbaix thermodynamics. Under photocatalytic operating conditions with visible light excitation of the plasmonic Au nanoparticles, further oxidation of CuI to CuII is observed, indicating light-driven hole transfer from Au-to-Cu. This observation is supported by the calculated band alignments of the oxidized Cu compositions with plasmonic Au particles, where light-driven hole transfer from Au-to-Cu is found to be thermodynamically favored. These findings demonstrate that under unassisted (unbiased) gas-phase reaction conditions, Cu is found in carbonate-rich oxidized compositions rather than metallic Cu. These species then act as the active cocatalyst and play an oxidative rather than a reductive role in catalysis when coupled with plasmonic Au particles for light absorption, possibly opening an additional channel for water oxidation in this system.

Fabrication of composite nanoparticles via electrostatic assembly and its application in ceramics preparation

Fabrication of composite nanoparticles via electrostatic assembly and its application in ceramics preparation

Development of Zanthoxylum bungeanum essential oil Pickering emulsions using potato protein-chitosan nanoparticles and its application in mandarin preservation

This study aimed to develop Pickering emulsions for the encapsulation of Zanthoxylum bungeanum essential oil (ZBEO) using potato protein-chitosan composite nanoparticles (PCCNs). The sustained release properties of ZBEO, antifungal efficacy, and preservation effects of formulated ZBEO-Pickering emulsions (ZBEO-PEs) on mandarins were evaluated. Particle size, zeta potential, emulsifying activity (EAI), and emulsifying stability (ESI) analysis showed that PCCNs prepared with the potato protein to chitosan mass ratio of 10:3 provided optimal emulsification and stabilization. Techniques such as differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) demonstrated that chitosan introduction increased the wettability of potato protein through electrostatic, hydrogen bonding, and hydrophobic interactions. ZBEO-PEs formulated with 3.0 % PCCNs and an oil fraction of 0.40 showed best encapsulation efficiency, storage stability and sustained release. Confocal laser scanning microscopy confirmed the adsorption of PCCNs, forming dense interface layers on the surface of oil droplets, thereby enhancing the stability of ZBEO-PEs. In vitro experiments demonstrated enhanced antifungal activity of ZBEO-PEs against Penicillium italicum and Penicillium digitatum. Additionally, storage experiments indicated that ZBEO-PEs coatings effectively controlled postharvest decay caused by Penicillium spp. in mandarins. Overall, the findings suggest that PCCNs are highly efficient emulsifiers for ZBEO Pickering emulsions, underscoring their potential as preservative coatings for mandarins.

Graphitic carbon @ silver nanoparticle @ porous silicon Bragg mirror composite SERS substrate for gallic acid detection

Graphite carbon (G) @ silver (Ag) @ porous silicon Bragg mirror (PSB) composite SERS substrate was successfully synthesized using electrochemical etching (ec) and hydrothermal carbonization (HTC) techniques with silver nitrate as the source of silver and glucose as the source of carbon. The PSB was used as a functional scaffold for the synthesis of graphite-carbon and silver composite nanoparticles (G@AgNPs) on its surface, thereby combining SERS activity and antioxidant properties. To our knowledge, this is the first time that G@AgNPs has been synthesized on the PSB using glucose as a carbon source. The synthesized G@Ag@PSB was utilized as a SERS platform for the detection of gallic acid (GA). Test results demonstrated that the substrate exhibited a remarkable SERS enhancement capability for GA, with the enhancement factor (EF) reaching 2 × 105. The reproducibility of the SERS spectral signal was excellent, with a relative standard deviation (RSD) of 7.5 %. The sensitivity test results showed that the linear range of GA detection based on G@Ag@PSB composite SERS substrate was 2 × 10-3-2 × 10-12M. The relationship between GA concentration and SERS signal intensity exhibited a strong linear correlation, with a linear correlation coefficient (R2) of 0.97634. Moreover, even with an extended storage period, only a marginal decline in the signal intensity of GA on the substrate was observed. The results of this study demonstrate that the prepared G@Ag@PSB composite SERS substrate had good potential application performance as a low-cost SERS detection platform suitable for commercial use. In addition, this advance facilitates the further exploration of more nanomaterials with ultra-high sensitivity in SERS technology.

Green synthesis of silver nanoparticles from the essential oil of Curcuma amada and their antihyperglycemic effect in STZ induced diabetic rats

A surfactant-free environmentally friendly approach for synthesising silver nanoparticles using Curcuma amada rhizome essential oil has been demonstrated. The composition and structure of silver nanoparticles are analysed using transmission electron microscopy, UV–visible spectroscopy, and Fourier transform infrared spectroscopy. The identification of a surface plasmon band at 428 nm by UV–visible spectroscopy provides preliminary evidence for the formation of silver nanoparticles. The transmission electron microscope verifies that the silver nanoparticles have an average particle size of 12.4 nm confirming a spherical shape. Self-stabilization of silver nanoparticles is discussed and correlated with the in-situ grafting of oil functional groups on surface nanoparticles. In-vitro and in-vivo antidiabetic studies are done for silver nanoparticles considering their antidiabetic potential, low toxicity, and the presence of curcumin functionalities on their surface. Specifically, the in-vitro study is done with α-amylase assay and in-vivo antidiabetic studies are done with streptozotocin-induceddiabetic rats. The percentage inhibition of α-amylase assay by silver nanoparticles is found concentration (20 μl–100 μl) dependent. The best result is seen at 100 μl concentration of silver nanoparticles (72 % inhibition) which is near to the standard taken (acarbose, 78 % inhibition). In-vivo study, the toxicity of two doses of Curcuma amada rhizome essential oil (200 mg/kg and 400 mg/kg) and synthesized silver nanoparticles (5 and 10 mg/kg) is checked and it is found safe. During the invivo study, silver nanoparticles with a dose of 5 mg/kg are capable of lowering the blood glucose level of all the streptozotocin-induced diabetic rats within 21 days (range ∼340–120 mg/dL). The histopathological analysis also supported the fact that there is an improvement in the pancreatic β-cells of all the diabetic groups compared to control group.

PH and temperature dual-responsive magnetic yolk-shell mesoporous silica nanoparticles for controlled drug delivery

New magnetic yolk-shell mesoporous silica nanoparticles (Fe3O4@V-mSiO2-PNVCL) were prepared by grafting temperature-sensitive amino-terminated poly (N-vinylcaprolactam) (PNVCL-NH2) on the surface of aldehyde-functionalized magnetic mesoporous silica nanoparticles (Fe3O4@V-mSiO2-CHO) through a Schiff base reaction. Various characterizations were used to confirm the structures, and the drug loading and release behaviors were studied. The drug loading was achieved as PNVCL stretched at room temperature and the drug loading content was up to 54.7% due to the large cavities. The encapsulation of drug from leakage in the blood environment was realized as PNVCL collapsed at physiological temperature. The fracture of pH-liable imine bonds in a slightly acidic tumor environment triggered the burst release of cargo. The Fe3O4@V-mSiO2-PNVCL showed super paramagnetic behavior (21.01 emu∙g−1) which could achieve magnetic targeting. The MTT assay confirmed that the nanoparticles exhibited low cytotoxicity. Furthermore, the cellular uptake experiments indicated that DOX-loaded nanoparticles were successfully internalized into cancer cells. Therefore, the composite nanoparticles are ideal choices for drug carriers.

Tribological, mechanical, and thermal properties of nano tricalcium phosphate and silver particulates reinforced Bis-GMA/TEGDMA dental resin composites

The proposed study is based on fabricating a hybrid dental composite of nano tricalcium phosphate and silver nanoparticles with resin matrix. Silver nanoparticles (20 wt%) and tricalcium phosphate (0–4 wt%) were incorporated in Bis-GMA/TEGDMA resin matrix. Photo initiator and accelerator were also employed for the polymerization of dental composites. Wear or tribology analysis of dental composites was performed on pin on disc setup. Physical, thermal, and mechanical properties were investigated under ASTM parameters. Void, water solubility, and sorption increased with an increment of filler loading. Maximum polymerization shrinkage 3.85 ± 0.02 % and depth of cure 2.57 ± 0.12 mm indicated by control sample TAg0. Taguchi L25 orthogonal array was used as a design of experiment (DOE) for wear analysis. TGA revealed the thermal stability in the form of: TAg0 > TAg1 > TAg2 > TAg3 > TAg4 in the range of 22–100 ̊C. In conclusion, the direct restorative material composed by the hybrid showed good mechanical and physical properties and potential thermal results, widening the scope of Ag and tricalcium phosphate in the dental composites.

Rational Design and Evaluation of Photoactive Molecularly Imprinted Nanoparticles for Tetracycline Degradation Under Visible Light.

This work presents the use of photoactive molecularly imprinted nanoparticles (MINs) to promote antibiotic degradation under visible light irradiation. Prototype MINs for the model antibiotic tetracycline (TC) were developed using molecular dynamics simulations to predict the TC-binding capacity of seven pre-polymerization mixtures. The studied formulations contained varying proportions of functional monomers with diverse physicochemical profiles, namely N-isopropylacrylamide (NIPAM), N-tert-butylacrylamide (TBAM), acrylic acid (AA), and (N-(3-aminopropyl)methacrylamide hydrochloride) (APMA) and a constant ratio of the cross-linker N,N'-methylene-bis-acrylamide (BIS). Two monomer formulations showed markedly higher TC-binding capacities based on template-monomer interaction energies. These mixtures were used to synthesize photoactive MINs by high-dilution radical polymerization, followed by the EDC/NHS conjugation with the organic photosensitizer toluidine blue. MINs showed higher TC-binding capacities than non-imprinted nanoparticles (nINs) of identical composition. MINs and nINs exhibited photodynamic activity under visible light irradiation, as confirmed by singlet oxygen generation experiments. TC degradation was evaluated in 50 μmol L-1 solutions placed in microplate wells containing immobilized nanoparticles and irradiated with white LED light (150 W m-2) for 1 h at room temperature. Degradation followed pseudo-zero-order kinetics with accelerated profiles in MIN-containing wells. Our findings suggest a key role of molecularly imprinted cavities in bringing TC closer to the photosensitizing moieties, minimizing the loss of oxidative potential due to reactive oxygen species diffusion. This degradation strategy can potentially extend to any organic pollutants for which MINs can be synthesized and opens valuable opportunities for exploring novel applications for molecularly imprinted materials.

Improving passive daytime radiative cooling via incorporation of composite nanoparticles into sheath of PU-PVDF core-sheath nanofiber film

Climate change has recently caused more severe temperatures, increasing demand for personal thermal management outdoors. Radiative cooling fabrics, known for their potent cooling ability, play a crucial role in regulating the thermal balance of the human body in high-temperature environments. In this study, an innovative PU (polyurethane)-SiO2/TiO2@PVDF (polyvinylidene fluoride) core-sheath nanofiber film was developed by incorporating SiO2/TiO2 composite nanoparticles (STNs) into the sheath of the nanofibers through coaxial electrospinning. The PU-STNs@PVDF composite nanofiber film with thickness of ∼100 μm achieved a reflectance of 92 % in the visible to near-infrared spectral range and an emittance of 91 % within the atmospheric transparent window. The temperature of the PU-STNs@PVDF core-sheath nanofiber film was reduced by 6.9 °C and 4.7 °C compared with that of the cotton fabric and PU-PVDF nanofiber film, respectively. Under direct solar radiation in summer, the temperature of the PU-STNs@PVDF core-sheath nanofiber film was 7.7 °C lower than that of cotton fabric. The PU-STNs@PVDF core-sheath nanofiber film elongated at a break of 127.5 % and a tensile strength of 4.3 MPa, implying it promising flexibility. The PU-STNs@PVDF core-sheath nanofiber film possesses huge potential in personal thermal management.

Bioremediation of crude oil polluted surface water using specialised alginate-based nanocomposite beads loaded with hydrocarbon-degrading bacteria and inorganic nutrients

This study explored the elimination of petroleum from river water using matrix-bound composites of iron oxide nanoparticles (IONPs) decorated on biochar with immobilized hydrocarbon-degrading bacteria (HCB) and monoammonium phosphate (MAP) at 10%v/v pollution levels. The beads containing biochar and IONPs (BCNP) showed better pollutant removal than those with biochar alone (BC). The treatment with beads containing biochar, IONPs, HCB and MAP had the highest removal efficiency for TPH (98.5%) and PAH (93.7%) and the lowest biodegradation half-lives. The removal efficiency for TPH and PAH was greater in the treatment microcosms than in the controls with significant differences (p ≤ 0.05) between the two groups. TPH and PAH elimination levels differed significantly (p ≤ 0.05) between systems with the BC bead and those with the BCNP beads. The study revealed a steady increase in the abundance of the total cultivable heterotrophic bacteria and cultivable hydrocarbon utilizing bacteria in the treatment microcosms after an initial decline, with strong negative correlation between bacterial abundance and TPH and PAH concentrations based on r values (0.5 − 1.0) and shared variances obtained. Bacillus, Pseudomonas and Klebsiella pneumoniae dominated as the drivers of the bioremediation process while organic acids and esters (25.0%) and ketones (14.3%) were the main biodegradation metabolite groups.

Multi-functional amorphous/crystalline interfaces rendering strong-and-ductile nano-metallic-glass/aluminum composite

Metal matrix composites (MMCs) are the materials-of-choice for a large range of important applications under harsh service conditions. However, owing to the high phase contrast between the matrix and the reinforcements, the strength-ductility conflict of MMCs is still outstanding. Here we fabricated a novel aluminum (Al) matrix composite reinforced by deformable, cobalt-zirconium-boron (CoZrB) metallic glass nanoparticles. The amorphous CoZrB/Al composite with only 2.0 vol.% particle reinforcements possessed a uniaxial tensile strength of 387.0 ± 1.2 MPa, showing over 80 % improvement over the unreinforced pure Al matrix at a similar uniform elongation. The strength-ductility synergy of the composite was also significantly superior to that of the composite reinforced by fully crystallized nanoparticles. These findings were rationalized by the unique multi-functionality of the amorphous particle/matrix interfaces, which effectively transferred the load from the matrix to the particles, coordinated the co-deformation of the nanoparticles and the matrix, and imparted a transgranular fracture mode in the composite with extensive matrix plastic deformation. The methodology developed in this study was shown to be generally effective for other matrix and metallic glass nanoparticle compositions, and our work may shed new light on the development of high-performance metal matrix composites for advanced structural applications.