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Pt-based nanocatalysts offer excellent prospects for various industries. However, the low loading of Pt with excellent performance for efficient and stable nanocatalysts still presents a considerable challenge. In this study, nanocatalysts with ultralow Pt content, excellent performance, and carbon black as support were prepared through in-situ synthesis. These ∼2-nm particles uniformly and stably dispersed on carbon black because of the strong s–p–d orbital hybridizations between carbon black and Pt, which suppressed the agglomeration of Pt ions. This unique structure is beneficial for the hydrogen evolution reaction. The catalysts exhibited remarkable catalytic activity for hydrogen evolution reaction, exhibiting a potential of 100 mV at 100 mA·cm−2, which is comparable to those of commercial Pt/C catalysts. Mass activity (1.61 A/mg) was four times that of a commercial Pt/C catalyst (0.37 A/mg). The ultralow Pt loading (6.84wt%) paves the way for the development of next-generation electrocatalysts. [ABSTRACT FROM AUTHOR]

A cost-effective industrial TiOSO4 solution was employed to fabricate visible light active sulfur-doped titanium dioxide (S-TiO2) via a facile hydrothermal method. The effect of calcination temperature on morphology, particle size, crystallinity, and photocatalytic property of S-TiO2 was systematically investigated. Successful incorporation of sulfur into TiO2 was confirmed by carbon-sulfur analysis, X-ray photoelectron spectroscopy (XPS), and Energy dispersive spectrometer (EDS). The research results demonstrated that calcination temperature significantly impacted the crystallinity, specific surface area, sulfur content, and light absorption properties of S-TiO2. The catalyst calcined at 400 °C revealed the highest photocatalytic activity, with a rate constant of 0.02408 min−1, approximately 25 times higher than commercial P25 catalyst. The higher activity was attributed to the synergistic effect of well-crystallized anatase phase, specific surface area, and red shift of spectral absorption. [ABSTRACT FROM AUTHOR]

The present study reports in-situ synthesis of porous silica-ruthenium composite catalyst for hydrolysis of ammonia borane. The in-situ synthesized catalyst precursors were prepared via sol-gel based methods using surfactant micelles of cethyltrimethylammonium bromide (CTAB) to form well-ordered nanopores in the precursor particles. The precursors consisted of spherical particles with the diameter of ca. 20–60 nm and nanopores with the diameter of ca. 2–3 nm were included in the precursor particles. The specific surface areas and pore volumes decreased with increasing of ruthenium content, while their catalytic activity for hydrogen generation from aqueous ammonia borane solution was the same level regardless of the ruthenium contents. The catalytic activity was effectively improved via reflux procedure of the precursors through removing residual compound probably originated from CTAB with maintaining dispersion of the active ruthenium species after the procedure. [ABSTRACT FROM AUTHOR]

Developing oxygen evolution reaction (OER) electrocatalysts in an efficient strategy, while maintaining high catalytic activity and stability under high current densities, remains a crucial problem. In this study, a bimetallic iron‐cobalt phytic acid complex loaded with polyaniline hollow structure (FCP@PAn) was successfully constructed, via a progress of selective etching and surface modification in one step without high‐temperature phosphating or carbonization. The as‐obtained FCP@PAn required only 329 and 385 mV overpotentials at high current densities of 500 and 1000 mA cm−2, respectively, due to phytic acid and polyaniline incorporation and the coordinated effect of each component. Additionally, the FCP@PAn exhibited the lowest Tafel slope values of 44.6 mV dec−1 and was able to continuously operate for 120 h at 500 mA cm−2, displaying high catalytic activity and stability. Hence, the hollow structure of the conductive polymer and MOFs composites provided a new surface modification strategy for transition metal‐based catalysts that are prone to dissolution or corrosion during the OER process, as well as for high current density applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Inorganic lead halide perovskite (LHP) nanostructures, represented by formula CsPbX3 (X = Cl, Br, I), have garnered considerable interest for their exceptional optical properties and diverse applications. Despite their potential, challenges such as environmental degradation persist. In‐situ synthesis within protective materials pores is a promising way to address this issue. However, confining perovskite nanostructures into porous matrices during the synthesis can limit their photoluminescence quantum yield (PL QY) and tunability of optical properties. Various post‐treatment approaches exist to improve the properties of LHP and achieve their desired functionalities, but these strategies have not been explored for LHP confined in mesoporous matrices. Here, we demonstrate the efficacy of in‐situ post‐synthetic treatments to improve the optical properties of CsPbBr3 nanocrystals grown in nanoporous silica microspheres. Surface passivation with Br– ion‐containing precursors boosts PL QY, while anion‐assisted cation doping with Mn2+ ions introduces a new PL band. The adjustment of precursor amount and doping duration enables precise control over the optical properties of LHP, while additional coating with a SiO2 shell enhances their stability in polar solvents, expanding the potential applications of these composites. [ABSTRACT FROM AUTHOR]

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office 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.)

Vegetable oil-based lubricants have a tendency to replace traditional petroleum-based lubricants due to their biodegradability, high flash point, low volatility, and low cost. However, polar molecules such as fatty acids in vegetable oil compete for adsorption with nanoparticles during rubbing process, resulting in imperfect tribological performance of nanoparticles. Magnetic nanoadditives can be adsorbed on the contact surface of iron-based friction materials through magnetic effects, which provides a new idea for solving competitive adsorption problems between additives and base oil. In this study, Ni nanoparticles with a particle size of approximately 15.6 nm were synthesized in-situ in olive oil using nickel acetylacetone as the nickel source and olive oil as the modifier and solvent required for the reaction, which is a simple, efficient, and environmentally friendly in-situ synthesis method. The as-synthesized Ni nanoparticles can significantly improve the antiwear capabilities of olive oil, reducing the wear scar diameter by 30%. The morphology and elemental analysis of wear scar indicated that a composite tribofilm including nickel, nickel oxide, iron oxide, carbon film, and polar fatty acid molecules in olive oil is formed on the rubbing surface, greatly improving the antiwear performance, which opens up an opportunity for the further application of new green nanolubricants. [ABSTRACT FROM AUTHOR]

In this study, the novelly designed Sr 0.5 Zr 2 (PO 4) 3 –Ce 0.5 Sm 0.5 PO 4 composite ceramics were utilized as nuclear waste form to simultaneously immobilize simulated fission products Sr and actinide nuclides. The phase transition mechanism, thermokinetics and densification behavior of Sr 0.5 Zr 2 (PO 4) 3 –Ce 0.5 Sm 0.5 PO 4 composite ceramics based on in-situ synthesis were systemically analyzed by XRD, in-situ XPS, TG-DSC, SEM and density measurements. The results demonstrate that the formation of Ce 0.5 Sm 0.5 PO 4 solid solution phase preceded that of Sr 0.5 Zr 2 (PO 4) 3 phase, of which there is a valence change of Ce from Ce4+ to Ce3+ before 1023 K. Additionally, as for the exothermic crystallization enthalpy, change of exothermic crystallization enthalpy and activation energy, the values of Sr 0.5 Zr 2 (PO 4) 3 and Ce 0.5 Sm 0.5 PO 4 phases in composite ceramics are 286.17 – 515.61 mJ, 19.11 – 35.38 J/g, 702.45 kJ/mol and 145.21 – 232.44 mJ, 9.26 – 15.44 J/g, 450.04 kJ/mol, respectively. It is then indicated that the formation of Ce 0.5 Sm 0.5 PO 4 phase is definitely more favorable than that of Sr 0.5 Zr 2 (PO 4) 3 phase. Simultaneously, the relative densities of Sr 0.5 Zr 2 (PO 4) 3 –Ce 0.5 Sm 0.5 PO 4 composite ceramics are more than 95 % when the sintering temperature exceeds 1273 K. [ABSTRACT FROM AUTHOR]

In order to obtain Al–Al2O3–ZrO2 composite refractories with excellent oxidation resistance, erosion resistance and thermal shock stability, metallic aluminium and fused Al2O3–ZrO2 were used as the raw materials, while phenolic resin was used as the binding agent. The microstructure was characterised by means of X-ray diffraction and scanning electron microscopy tests. Based on the reaction between zirconia and metallic aluminium under N2 flowing at 1300 °C, the reaction mechanism of zirconia and metallic aluminium in-situ reaction at 1300 °C to generate (Al2OC)x(AlN)1−x solid solution, zirconium nitride, and aluminium–zirconium alloy was revealed, and a model for the evolution of the phases in the aluminium-added Al–Al2O3–ZrO2 specimen was constructed to realise the Al–Al2O3–ZrO2 composite refractories phase controlling. Based on the good corrosion resistance of ZrO2 to CaO and the excellent results of the in-situ reaction of metallic aluminium to generate a large number of non-oxide reinforcing phases capable of replacing elemental C, this work is of great significance for the study of refractory in erosion-heavy environments, such as calcium-treated steel. [ABSTRACT FROM AUTHOR]

This work investigated in‐situ synthesis of porous silica‐nickel‐ruthenium composite catalysts for hydrolysis of ammonia borane. The precursors were prepared with an anionic surfactant, sodium dodecyl sulfate (SDS), to form porous structure in the precursor particles, and the precursors was treated in aqueous solution including sodium borohydride and ammonia borane for in‐situ process to parallelly activate and use the catalysts for hydrolysis of ammonia borane. The result of TEM and nitrogen sorption measurements suggested that the primary particle size of the in‐situ synthesized catalysts decrease with increasing the amount of SDS and sodium chloride as the additive for controlling the primary particle size probably because of the effect of sodium ions to inhibit nuclei growth of the primary particles. From the EDS analyses, the composition of active nickel and ruthenium contents increased with increasing the amount of SDS and sodium chloride except for the highest amount of SDS probably because of adsorption of the metal cations with the excess amount of the surfactant anion to decrease the amount of the metal cations including the catalyst. The in‐situ synthesized catalyst including small size primary particles and high nickel and ruthenium content tended to exhibit high activity for hydrolysis of ammonia borane. [ABSTRACT FROM AUTHOR]

With the increase in train speed and axle weight, the quality and service life of the rail (U71Mn steel) are more demanding. Aiming at the excellent properties of nickel/nickel-based alloys and ceramic materials, this paper prepares TiC/Ni45 composite coatings for rail repair by in-situ synthesis of ceramic phases using laser cladding technology. The effects of in-situ synthesized TiC on the physical phase, microstructure, microhardness and wear resistance were investigated and discussed in detail. The results show that the reaction of in-situ synthesized TiC can proceed positively, and the microstructure of the cladding layer mainly consists of the segregation of Cr, TiC particles, and substrate phase. With the increase of nickel-coated graphite and titanium powder, the average microhardness value of the cladding layer increased, and the average friction coefficient and wear volume decreased. When the mass fraction of (Ti + C) reaches 15 wt%, the average friction coefficient of the cladding layer reaches the minimum value. When the mass fraction reaches 20 wt%, the average microhardness of the cladding layer reaches 2.65 times that of the substrate, and the wear mechanism is transformed from mainly adhesive wear to abrasive, oxidative, and fatigue wear. [ABSTRACT FROM AUTHOR]

The development of safe, low-cost and highly active non-precious metal electrocatalysts plays a vital role in efficient hydrogen production. Herein, Mo2C/Mo2N heterostructure was in-situ synthesized by a two-step method for excellent hydrogen evolution performance at a universal pH range. The results show that the optimized MoCN-750-2h only needs 86.5, 102.5 and 120.5 mV overpotentials to reach 10 mA·cm−2 in alkaline, acidic and neutral media, respectively. Not only that, MoCN-750-2h had a low Tafel slope (37.2 and 88.5 mV·dec−1) in alkaline and neutral media, implying that catalytic kinetic is close to the level of Pt/C. These results can be attributed to reasonable C and N content in MoCN-750-2 h, optimizing the electron cloud distribution of Mo2C/Mo2N heterostructure to boost hydrogen production. MoCN heterostructure was in-situ synthesized by a two-step method for excellent hydrogen evolution performance at a universal pH range. The optimized electron cloud distribution of Mo2C/Mo2N would promote the formation of electron transfer channels, boosting the hydrogen evolution catalytic activity of the heterostructure. The MoCN heterostructure only needs 86.5,102.5 and 120.5 mV overpotentials to reach 10 mA·cm−2 in alkaline, acidic and neutral media, respectively. Not only that, MoCN-750-2 h had a low Tafel slope (37.2 and 88.5 mV·dec−1) in alkaline and neutral media, implying that catalytic kinetic is close to the level of Pt/C. [ABSTRACT FROM AUTHOR]

Incorporating carbon nanotubes (CNTs) into Al-Si alloy to prepare in-situ SiC/Al-Si composites enhances thermal conductivity (TC) and reduces the coefficient of thermal expansion (CTE). However, challenges include CNTs aggregation and uneven SiC distribution. This study uses fluidized bed chemical vapor deposition (FBCVD) to achieve uniform CNTs coverage on Al-50Si powder. Subsequent powder hot extrusion and heat treatment above the eutectic temperature enable a gradual reaction between CNTs and Al/Si atoms, resulting in uniformly dispersed SiC within the SiC/Al-50Si composite. The formation mechanism of in-situ SiC particles and their impact on the microstructure, thermal and mechanical properties of the composite are further investigated. The formation process involves a two-step chemical reaction: lamellar Al4C3 phases transform into lamellar eutectic SiC + Al phases, which then transition into polyhedral SiC particles through epitaxial growth. This in-situ formation of SiC particles also impedes Si growth during heat treatment, refining Si particles and enhancing the composite’s properties. The resulting in-situ SiC/Al-50Si composite exhibits excellent thermal and mechanical properties, including a high TC of ∼162 Wm-1K−1, a low CTE of ∼ 8.7 × 10-6/K, and a good bending strength of approximately 253 MPa at room temperature.

The WC prepared by in-situ synthesis usually has the deficiency of coarse grains and low synthetic content due to its low nucleation drive. In this work, different contents of WCs were added as nucleation sites to enhance the synthesis reaction between carbon and tungsten by reducing the nucleation energy. The results showed that the composite coatings were dense, crack-free, and mainly composed of WC and Fe0.64Ni0.36 phases. Due to a significant increase in the nucleation rate, the content of WC was increased from 38.08% to 53.15% and the WC grains were also significantly refined. The composite coating showed the lowest wear rate of 1.07 × 10−6 mm3 N−1 m−1 when the pre-added WC content was 15 wt%, which was ascribed to the high content of synthetic WC with high microhardness around 2200 HV0.1 and the fine grain strengthening of the large number of about 1 μm WCs.

In this work, Sr0·5Zr2(PO4)3-SmPO4 dual-phase ceramics were prepared via in-situ synthesis process, which is a potential novel nuclear waste form for immobilizing the fission product 90Sr and the trivalent actinide radionuclides in high-level waste (HLW). And the preparation technology, microstructure and chemical durability of Sr0·5Zr2(PO4)3-SmPO4 dual-phase ceramics were systematically investigated. It was confirmed that the optimum microwave-sintering temperature (1050 °C) and heat preservation time (1.5 h) is estimated by Archimedes method. Besides, the as-prepared samples that were consisted of strontium zirconium phosphate (SrZP) and monazite showed the remarkable densification, in which the two crystalline phases were intermixed well with each other. Meanwhile, the formation and evolution of microstructure was also consistent with the variational rule of Sr0·5Zr2(PO4)3/SmPO4, indicating that there was not mutual reaction during the in-situ synthesis process. The PCT and MCC-1 experimental results demonstrated that the elemental normalized leaching rates of tested samples are all at a low level (LRSr ∼10−4 g‧m−2‧d−1, LRZr ∼10−8-10−6 g‧m−2‧d−1, LRSm ∼10−7-10−5 g‧m−2‧d−1 and LRP ∼10−4 g‧m−2‧d−1). It is indicated that Sr0·5Zr2(PO4)3-SmPO4 dual-phase ceramics possesses excellent chemical durability for HLW disposal.

Abstract This project investigated the impact of low-temperature, in-situ synthesis of cerium oxide (CeO2) nanoparticles on various aspects of oil recovery mechanisms, including changes in oil viscosity, alterations in reservoir rock wettability, and the resulting oil recovery factor. The nanoparticles were synthesized using a microemulsion procedure and subjected to various characterization analyses. Subsequently, these synthesized nanoparticles were prepared and injected into a glass micromodel, both in-situ and ex-situ, to evaluate their effectiveness. The study also examined the movement of the injected fluid within the porous media. The results revealed that the synthesized CeO2 nanoparticles exhibited a remarkable capability at low temperatures to reduce crude oil viscosity by 28% and to lighten the oil. Furthermore, the addition of CeO2 nanoparticles to the base fluid (water) led to a shift in the wettability of the porous medium, resulting in a significant reduction in the oil drop angle from 140° to 20°. Even a minimal presence of CeO2 nanoparticles (0.1 wt%) in water increased the oil production factor from 29 to 42%. This enhancement became even more pronounced at a concentration of 0.5 wt%, where the oil production factor reached 56%. Finally, it was found that the in-situ injection, involving the direct synthesis of CeO2 nanoparticles within the reservoir using precursor salts solution and reservoir energy, led to an 11% enhancement in oil production efficiency compared to the ex-situ injection scenario, where the nanofluid is prepared outside the reservoir and then injected into it.

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office 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.)

Fluorescent‐patterned materials are widely used in information storage and encryption. However, preparing a patterned fluorescent display on a matrix currently requires a time‐consuming (hours or even days) and complex multi‐step process. Herein, a rapid and mild technique developed for the in‐situ controllable synthesis of fluorescent nitrogen‐doped carbon dots (NCDs) on eco‐friendly transparent wood films (TEMPO‐oxidized carboxyl wood film [TOWF]) within a few minutes was developed. A wood skeleton was employed as the carbon precursor for NCD synthesis as well as the matrix for the uniform and controlled distribution of NCDs. Moreover, the in‐situ synthesis mechanism for preparing NCDs in TOWF was proposed. The resulting fluorescent wood films have excellent tensile strength (310.00 ± 15.57 MPa), high transmittance (76.2%), high haze (95.0%), UV‐blocking properties in the full ultraviolet (UV) range, and fluorescent performance that can be modified by changing the heating parameters. Fluorescent patterning was simply achieved by regulating the in‐situ NCD synthesis regions, and the fluorescent patterns were formed within 10 s. These fluorescent‐patterned wood films can effectively store and encrypt information, and they can interact with external information through a transparent matrix. This work provides a green and efficient strategy for fabricating fluorescent information storage and encryption materials. [ABSTRACT FROM AUTHOR]

This project investigated the impact of low-temperature, in-situ synthesis of cerium oxide (CeO2) nanoparticles on various aspects of oil recovery mechanisms, including changes in oil viscosity, alterations in reservoir rock wettability, and the resulting oil recovery factor. The nanoparticles were synthesized using a microemulsion procedure and subjected to various characterization analyses. Subsequently, these synthesized nanoparticles were prepared and injected into a glass micromodel, both in-situ and ex-situ, to evaluate their effectiveness. The study also examined the movement of the injected fluid within the porous media. The results revealed that the synthesized CeO2 nanoparticles exhibited a remarkable capability at low temperatures to reduce crude oil viscosity by 28% and to lighten the oil. Furthermore, the addition of CeO2 nanoparticles to the base fluid (water) led to a shift in the wettability of the porous medium, resulting in a significant reduction in the oil drop angle from 140° to 20°. Even a minimal presence of CeO2 nanoparticles (0.1 wt%) in water increased the oil production factor from 29 to 42%. This enhancement became even more pronounced at a concentration of 0.5 wt%, where the oil production factor reached 56%. Finally, it was found that the in-situ injection, involving the direct synthesis of CeO2 nanoparticles within the reservoir using precursor salts solution and reservoir energy, led to an 11% enhancement in oil production efficiency compared to the ex-situ injection scenario, where the nanofluid is prepared outside the reservoir and then injected into it. [ABSTRACT FROM AUTHOR]

This work presents for the first time one-step ultrafast (precursor-free) synthesis of 1D MnFe 2 O 4 (MFO) nanorods and soft magnetic colloidal nanoparticles (NPs) using microwave-assisted hydrothermal (MAH) methods, with or without citric acid (CA) as a surfactant (in situ synthesis), respectively. The mechanism of growth of spinel MFO nanostructures during the MAH synthesis was studied by varying synthesis duration (3–6 h) and temperature (180–200 °C). An increase in both the duration and temperature improved the purity of the samples, up to 97%. On the other hand, a temperature increase by 20 °C notably shortened the formation time of MFO nanorods, which have an average diameter and length of less than 20 nm and 350 nm, respectively, as observed at 200 °C after 6 h. All the fabricated MFO NPs with spherical and rod-like morphologies manifested high saturation magnetization in the range of 54–64 emu/g. The chelation of lattice metal ions by CA resulted in the formation of a stable colloid comprising 100% pure spinel MFO NPs with a size of ≤32 ± 10 nm (mean ± SD) and featuring very soft magnetic properties. This colloid was generated by the MAH synthesis at 175 °C within 30 min. Notably, an increase in synthesis duration from 30 min to 3 h diminished MFO phase purity from 100% to 52% and saturation magnetization from 43.4 ± 0.7 to 33.9 ± 2.0 emu/g for CA-functionalized MFO NPs owing to CA degradation increasing during the in situ MAH synthesis with longer duration. This study indicates good potential of ultrafast MAH synthesis for the development of 1D magnetic spinel nanostructures with controllable morphology, size, magnetic properties, and colloidal stability, thereby offering a wide range of applications within the fields of adsorption, catalysis, electronics, and biomedicine. [ABSTRACT FROM AUTHOR]

The construction of heterojunction is one of the most effective ways to improve the activity of photocatalysts, while in‐situ synthesis technology can provide the most intimate interfacial contact during the preparation of heterojunction. Heterojunction photocatalysts prepared by in‐situ synthesis have shown excellent performance in solar energy conversion and environmental purification. The convenient preparation process is also suitable for large‐scale production. In this review, we summarize the common synthesis methods and characterization techniques for the in‐situ synthesis of heterojunctions, and list the applications of these catalysts in the photocatalytic field. Finally, we discuss the limitations of the current research on in‐situ synthesis and look forward to its great prospects. [ABSTRACT FROM AUTHOR]

The present study reports an environmentally friendly in‐situ synthesis of novel antibacterial copper‐based MOFs within the hydrogel network of sodium alginate. Two different copper‐based MOF/sodium alginate composite beads were prepared via the post‐treatment of copper‐ion‐crosslinked alginate hydrogels with two different ligand solutions, namely, tartaric acid and oxalic acid, at 100 °C for 24 h. The structural, thermal, and morphological properties of the prepared samples were investigated using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), and their antibacterial activities against gram‐positive (Staphylococcus aureus and Bacillus) and gram‐negative (Escherichia coli and Pseudomonas aeruginosa) strains were examined using the conventional disc diffusion method. The results demonstrated the success of the in‐situ synthesis of two distinct copper‐based MOFs with FTIR spectra, confirming the existence of characteristic bands of the ligands complexed to the sodium alginate matrix. Moreover, the XRD diffractograms revealed the formation of two distinct crystalline structures with well‐defined morphologies observed in the SEM images. In addition, thermal analysis showed that the prepared composite beads had enhanced thermal stability compared to the copper‐ion‐crosslinked alginate beads. Antibacterial testing revealed the strong capacity of the copper‐based MOFs/sodium alginate composite beads to deactivate the growth of all the bacterial strains used, with a minimum inhibition zone of 23 mm, which highlights the potential of the synthesized materials as highly potent antibacterial agents. [ABSTRACT FROM AUTHOR]

A simple in-situ method was proposed to synthesize surface coating of SiC nanowhiskers on cordierite honeycombs by aluminothermic, silicothermic, and carbothermic reduction reactions. The surface coating of SiC nanowhiskers was synthesized by controlling the partial pressure of SiO gas on the surface of honeycombs, based on the pore-forming process using aluminium(Al) agent. Increasing the porosity of the honeycombs provided aisles to volatilize SiO gas, and the growth of SiC nanowhiskers changed from inside the honeycomb wall to on the honeycomb surface. SEM and TEM observations revealed that the relatively high porosity (≥45%) and sintering temperature (1250–1300 °C) were necessary for obtaining surface coating of SiC nanowhiskers, and the nanowhisker-coating having the smooth morphology and a thickness of ∼150 µm was obtained at 1250 °C. Compared with cordierite honeycombs without SiC nanowhiskers, SiC nanowhiskers inside the honeycomb walls could improve the compressive strength and thermal conductivity with increasing rates of 121% and 123%, respectively, and the surface coating of SiC nanowhiskers increased the specific surface area of the honeycombs by 241 times. [ABSTRACT FROM AUTHOR]

Despite prohibition in many countries, malachite green (MG) and crystal violet (CV) are illegally used in aquaculture, endangering both human health and the environment. Therefore, it is crucial to develop a method to accurately detect MG and CV. Surface-enhanced Raman spectroscopy (SERS) technology based on noble metal materials has attracted considerable attention for detecting food contaminations. However, noble metal materials are of poor stability and have a very low affinity for organic molecules. Herein, in this study, covalent organic frameworks (COFs) modified with silver nanoparticles (Ag NPs) were used as SERS substrates for the adsorption and detection of fungicides. COFs prepared by the Schiff base reaction of 1,3,5-tris (4-aminophenyl) benzene (TAPB) and 2,5-dimethoxybenzene-1,4-dicarboxaldehyde (DMTA) had a huge specific surface area and could provide sufficient adsorption sites and Ag NPs grown on the surface of COFs not only generated dense SERS "hot spots" but also improved their stability. The results showed that COF@Ag NPs exhibited a high enhancement factor (1.4 × 106), high reproducibility (RSD = 6.18%), and good stability within 50 days (RSD = 8.88%). Regression analyses in the ranges of 0.0001–10.0 mg/L and 0.0002–10.0 mg/L showed that the limits of detection (LOD) for the standard solutions of MG and CV were 3.8 × 10−5 mg/L and 1.8 × 10−5 mg/L, respectively. Furthermore, for MG and CV in fish samples, significant recoveries of 90.83–107.91% and 98.60–116.69% were achieved. Hence, it is hoped that this work could expand the application of COF materials for trace detection in SERS analyses. [ABSTRACT FROM AUTHOR]

Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength, low density, and high modulus. In this study, the TA15-based composites reinforced with a volume fraction of 10% to 25% (TiB+TiC) were prepared using powder metallurgy and casting technique. Microstructural characterization and phase constitution were examined using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In addition, the microhardness, room temperature (RT) and high temperature (HT) tensile properties of the composites were evaluated. Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC. However, as the volume fraction exceeds 15%, TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology. Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%. Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures, but it has an adverse effect on room temperature elongation. Conversely, if the reinforcement volume fraction is below 20%, it can improve high-temperature elongation when the temperature exceeds 600 °C. [ABSTRACT FROM AUTHOR]

MAX phase Ti3SiC2 has been synthesized via fast hot pressing (FHP) based on the raw materials of Ti, Si, TiC and Al powders with a molar ratio of 1:1.2:2.3:0.3. The theoretical thermodynamic calculation and DSC test were adopted to verify the feasibility of the synthetic route and sintering temperature. The X-ray diffraction (XRD) result indicated that there were few impurity phases except Ti3SiC2 formed in the sintered sample. The sectional morphology was observed by scanning electron microscope with almost all the platelike-shaped phases, which conformed to the morphology feature of Ti3SiC2. Transmission electron microscopy has been brought to demonstrate the accurate phase composition as Ti3SiC2 combined with the PDF card of XRD analysis. [ABSTRACT FROM AUTHOR]

Nickel (Ni) nanoparticles can be enriched on the surface of iron-based frictional pairs, which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-active nano-additives thereon. In this paper, nickel acetylacetonate was used as a precursor to in-situ synthesize nickel nanoparticles with an average diameter of about 12 nm in rapeseed oil (RO) as the reducing agent, surface modifier, and solvent as well. The tribological properties of the as-synthesized Ni nanoparticles were evaluated with a four-ball tribometer, and their tribomechanism was investigated based on the characterizations of the tribofilm on rubbed steel surfaces by the scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that the Ni nanoparticles in-situ prepared in the RO with a mass fraction of 0.3% can reduce the wear scar diameter (WSD) of the steel ball by 36%. This is because, on the one hand, the Ni nanoparticles are adsorbed on the rubbed steel surfaces to repair or fill up the micro-pits and grooves thereon. On the other hand, Ni nanoparticles participate in tribochemical reactions with atmospheric O and steel substrate to form the tribochemical reaction film on the rubbed steel surfaces with the assistance of friction-induced heat and applied normal load. In addition, an amorphous carbon film is formed on the rubbed surface via the carbonization of base oil under the catalysis of Ni nanoparticles. The adsorbed Ni layer, the tribochemical reaction film, and the carbon layer comprise a composite tribofilm composed of amorphous carbon, polar fatty acid, metallic nickel, iron oxides, and nickel oxides on the rubbed steel surfaces, which contributes to significantly improving the antiwear ability and load-carrying capacity of the RO for the steel–steel sliding pair. [ABSTRACT FROM AUTHOR]

Refractory metals and their carbides possess extraordinary properties when subjected to high temperatures and extreme environments. Consequently, they can act as key material systems for advancing many sectors, including space, energy and defence. However, it has been difficult to process these materials using the conventional routes of manufacturing. Additive manufacturing (AM) has shown a lot of potential to overcome the challenges and develop new material systems with tailored properties. This review provides a fundamental understanding of the challenges in the processing of refractory metals and their carbides, including microcracking, formation of brittle oxide phases and high ductile to brittle transition temperature (DBTT). We also highlight some of the novel approaches that have been taken to improve the processability of these challenging material systems using AM. These include in-situ reactive printing, ultrasonic vibration, laser beam shaping, multi-laser deposition and substrate pre-heating with a focus on microstructural changes to improve the properties of printed parts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A strategy of constructing porous N -doped carbon framework to improve NVP is proposed. • TEA serves as acid binding agent to convert PAA into polyamide salts. • PI was synthesized and decomposed to construct a porous framework. • N -doped carbon with rich-defects benefits for the migration of Na+ and electrons. • The optimized PAA-NVP-1 exhibits superior sodium storage property. Generally, the transport of electrons and Na+ is seriously constrained in Na 3 V 2 (PO 4) 3 (NVP) due to intense interactions of V-O and P O bonds. Besides, polyamide acid (PAA) is hardly used in the sol–gel route due to insolubility. This work develops a facile liquid synthesis strategy based on modified PAA, achieving in-situ construction of a porous N -doped carbon framework with rich defects to improve the kinetics of NVP. The addition of triethylamine (TEA) reacts with carboxyls in PAA to achieve acid-base neutralization, turning PAA into polyamide salts with good solubility. The special morphology construction mechanism of this unique system was observed by ex-situ scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Specifically, PAA undergoes in-situ conversion into chain-like polyimide (PI) through a thermal polymerization mechanism during the pre-sintering process. Meanwhile, NVP precursors are evenly dispersed in the PI fibers, efficiently reducing the particle size. After the final treatment, the favorable porous carbon skeleton could be generated derived from the partial decomposition of PI, on which small active grains are in situ grown. The resulting N -doped carbon substrate contains rich defects, benefiting from the migration of Na+. Furthermore, the porous construction is conducive to alleviating the stress and strain generated by the high current impact, increasing the contact area between electrodes/electrolytes to improve the utilization efficiency of active substances. Comprehensively, the optimized samples exhibit a capacity of 82.1 mAh g−1 at 15C with a retention rate of 95.45 % after 350 cycles. It submits a capacity of 67.6 mAh g−1 at 90C and remains 52.2 mAh g−1 after 1500 cycles. Even in full cells, it reveals a value of 110.6 mAh g−1. This work guides the application of in-situ multiple modifications of polymers in electrode materials. [ABSTRACT FROM AUTHOR]

Abstract Fluorescent‐patterned materials are widely used in information storage and encryption. However, preparing a patterned fluorescent display on a matrix currently requires a time‐consuming (hours or even days) and complex multi‐step process. Herein, a rapid and mild technique developed for the in‐situ controllable synthesis of fluorescent nitrogen‐doped carbon dots (NCDs) on eco‐friendly transparent wood films (TEMPO‐oxidized carboxyl wood film [TOWF]) within a few minutes was developed. A wood skeleton was employed as the carbon precursor for NCD synthesis as well as the matrix for the uniform and controlled distribution of NCDs. Moreover, the in‐situ synthesis mechanism for preparing NCDs in TOWF was proposed. The resulting fluorescent wood films have excellent tensile strength (310.00 ± 15.57 MPa), high transmittance (76.2%), high haze (95.0%), UV‐blocking properties in the full ultraviolet (UV) range, and fluorescent performance that can be modified by changing the heating parameters. Fluorescent patterning was simply achieved by regulating the in‐situ NCD synthesis regions, and the fluorescent patterns were formed within 10 s. These fluorescent‐patterned wood films can effectively store and encrypt information, and they can interact with external information through a transparent matrix. This work provides a green and efficient strategy for fabricating fluorescent information storage and encryption materials.

Biodegradable zinc (Zn)-based composites are considered to be the next generation of promising orthopedic implant materials due to their degradability and the multiple functionality of combining metal and ceramic phases. However, its clinical bone-implant application is seriously limited due to their poor interface binding ability and mechanical properties. Herein, we developed the biodegradable in-situ Zn–3Cu–10ZnO composite through powder metallurgy using Zn and copper (Cu) powder combined with hot forging, followed by the high-pressure solidification (HPS) process for bone-implant application. Microstructural characterization showed that the HPS process can densify composite, form a uniform distribution of fine ZnO particle, and increase Cu atom solid solubility in the Zn matrix. Mechanical test revealed that the HPS composite exhibited a high compression performance with a compressive yield strength of 340.8 MPa, an ultimate compressive strength of 514.2 MPa, and a failure strain of ≥70%. The HPS composite exhibited the lowest corrosion rate of 25.8 μm/y and 44.3 μm/y measured by electrochemical corrosion and immersion tests, respectively, among these composites. Moreover, the diluted extracts of HPS composite with a concentration of ent% showed a higher cytocompatibility among these composites and better antimicrobial capability than those of the as-cast pure Zn. Accordingly, the HPS Zn–3Cu–10ZnO composite is expected to be a potential biodegradable material for orthopedic applications.

Abstract Nickel (Ni) nanoparticles can be enriched on the surface of iron-based frictional pairs, which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-active nano-additives thereon. In this paper, nickel acetylacetonate was used as a precursor to in-situ synthesize nickel nanoparticles with an average diameter of about 12 nm in rapeseed oil (RO) as the reducing agent, surface modifier, and solvent as well. The tribological properties of the as-synthesized Ni nanoparticles were evaluated with a four-ball tribometer, and their tribomechanism was investigated based on the characterizations of the tribofilm on rubbed steel surfaces by the scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that the Ni nanoparticles in-situ prepared in the RO with a mass fraction of 0.3% can reduce the wear scar diameter (WSD) of the steel ball by 36%. This is because, on the one hand, the Ni nanoparticles are adsorbed on the rubbed steel surfaces to repair or fill up the micro-pits and grooves thereon. On the other hand, Ni nanoparticles participate in tribochemical reactions with atmospheric O and steel substrate to form the tribochemical reaction film on the rubbed steel surfaces with the assistance of friction-induced heat and applied normal load. In addition, an amorphous carbon film is formed on the rubbed surface via the carbonization of base oil under the catalysis of Ni nanoparticles. The adsorbed Ni layer, the tribochemical reaction film, and the carbon layer comprise a composite tribofilm composed of amorphous carbon, polar fatty acid, metallic nickel, iron oxides, and nickel oxides on the rubbed steel surfaces, which contributes to significantly improving the antiwear ability and load-carrying capacity of the RO for the steel–steel sliding pair.