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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.)

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]

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]

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.

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]

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.)

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.

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.

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]

[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]

Developing high-performance Pt-based electrocatalysts via the functionalization of carbon carriers is an enormous challenge for their versatile electrocatalytic applications. Herein, carbonaceous (CA) supporter enriched with oxygen-species and anchored by PtNiCo nanoparticles is in-situ synthesized by a "liquid-phase calcination" (LPC) approach. As a result, PtNiCo/CA obtained in polyethylene glycol presents excellent current density in methanol oxidation reaction (MOR) (435 mAmg−1Pt), higher half-wave potential (0.92 V) in oxygen reduction reaction (ORR), and lower overpotential (377 mV) at the current density of 100 mAcm−1 in oxygen evolution reaction (OER). Furthermore, the prepared electrocatalyst shows excellent durability in MOR, ORR, and OER processes. Characterizations including in-situ infrared spectroscopy indicated that the formed M − O species and oxygen-enriched carbonaceous support is conducive to the protonation and deprotonation behaviors, thus enhancing the activity and stability of Pt active sites. Our synthetic strategy shows a potential approach for preparing high-active and long-durable Pt-based versatile electrocatalysts. • PtNiCo/carbonaceous was fabricated by an in-situ LPC approach. • Carbonaceous supporter was enriched with oxygen-containing species. • PtNiCo alloy nanoparticles were deeply anchored in CA layer. • PtNiCo/CA exhibited excellent performance in MOR, ORR and OER. [ABSTRACT FROM AUTHOR]

The ever-evolving service conditions of high-end equipment continue to bring new challenges to the surface coating of the key components. Thus, modified nickel-based composite coatings with enhanced service performance must be further explored. The work aimed to improve the wear resistance and corrosion resistance of Ni-based coating by in-situ synthesis of TiC–TiB 2 composite ceramic phase using TA0, B 4 C, and nickel (Ni)-coated graphite. First, coatings with different contents of B 4 C (from 3 wt% to 6 wt%) and Ni-coated graphite (from 0 wt% to 8 wt%) were prepared by laser cladding. The microstructure, phase composition, microhardness, wear properties, and electrochemical properties of the coatings were examined. The increase in the C/Ti ratio after adding Ni-coated graphite led to a decrease in the nucleation rate of the ceramic phase in the molten pool. Ultimately, the size of the ceramic phase gradually increased. The coatings with 3 wt% B 4 C and 8 wt% Ni-coated graphite showed the best wear resistance, with a 26.47 % reduction in wear volume compared with those of Ni-based alloy coatings. The variation in wear properties was due to the change in wear form caused by the increase in the size of the ceramic phase within the coating. The corrosion potential of the coating added with in-situ TiC–TiB 2 increased by 39 % at best, and the corrosion current density was reduced by more than an order of magnitude. This finding was because the ceramic particles distributed throughout the grain boundaries increased the impedance of the coating and blocked the corrosion channels. This study provided theoretical guidance on the preparation of modified Ni-based coatings with excellent wear resistance and corrosion resistance. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society 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.)

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.

This study aimed to investigate the in-situ synthesis of nanostructured carbon materials using alcohol flames generated by a Bunsen lamp burner and a catalytic Ni substrate, as opposed to the chemical vapor deposition method. Four different liquid fuels were utilized, including n-butanol, ethanol, n-butanol/aqueous ammonia, and ethanol/aqueous ammonia. The carbon growth, morphology, and structure caused by the parameters of sampling position, temperature distribution, and liquid fuel type were investigated using the diffusion flame produced by the atmospheric alcohol lamp burner. The results show that the additive aqueous ammonia affects not only the flame temperature but also the axial position of the highest temperature. When using n-butanol and portions of 10 %, 20 %, and 30 % of aqueous ammonia mixed fuels, carbon nanotubes (CNTs), and carbon nano-onions (CNOs) are both observed; however, using ethanol and the portions of 10 %, 20 %, and 30 % of aqueous ammonia mixed fuels, only CNTs are synthesized. Soot particles show concentrically stacked carbon layers with a diameter of around 45 ± 5 nm. CNTs have no encapsulated Ni catalytic particles at the closed tip, showing the root growth mechanism and indicating differences from the top growth mechanism. In addition, graphene could be synthesized in pure n-butanol and n-butanol/ammonia flames, but not in pure ethanol and ethanol/ammonia flames. The IG/ID ratio values of the raw CNOs (2.33) and CNTs (1.05) are greater than 1, where IG/ID is the intensity ratio of Raman G-band and D-band peaks, indicating good crystallization of the graphite layer of these nanostructured carbon materials. Notably, flame synthesis via an alcohol Bunsen lamp burner simplifies operations saves resources, and improves conventional production, demonstrating a facile and efficient method.

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.

Current heterostructured materials have significant potential for improving the strength-ductility trade-off, but the interfacial bonding capabilities are limited. In this research, composites with TiN/Ti6Al4V interlayer structure were in-situ synthesized by atmospheric remelting using laser directed energy deposition (LDED). The elemental diffusion, microstructure, and mechanical properties of TiN/Ti6Al4V interlayer structure composites were investigated. The mechanical properties of the composites were improved after nitrogen remelting due to the strengthening of internal TiN ceramic particles. The microhardness of TiN/Ti6Al4V composites increased by up to 209.8% to 1141 HV0.2, ultimate tensile strength by 6% and elongation by 34.5% to 1071.4 MPa and 15.6%, respectively. This research demonstrates that a flexible combination of the LDED process and reaction atmosphere can synthesize new periodic layered ceramic/metal composites with excellent mechanical properties. This research offers the groundwork for the fabrication of in-situ strengthening continuous gradient materials.

In order to reveal the correspondence between the microstructure and mechanical properties of in-situ TiC/Ti composite coatings by induction fusion coating, the nano-mechanical property variation patterns of different phase structures within the coatings were investigated by using the isolated nanoindentation test method, and the mechanical properties of the coating micro-zone structure were studied by using grid indentation test method. The isolated indentation results show that the nanoindentation hardness and elastic modulus of the in-situ TiC-reinforced phases are 21.3 GPa and 275 GPa, respectively, while the average nano hardness of the matrix phase in the α-Ti-rich and β-Ti-rich regions is 4 GPa and 6 GPa, respectively, and the average elastic modulus is 130 GPa and 155 GPa, respectively. The correspondence between the grid indentation and isolated indentation test results is good. The minimum peak obtained from the three-peak Gaussian fitting of the fractional nanoindentation test results represents the mechanical properties of the matrix phase of the coating, the middle peak reflects the comprehensive mechanical properties of the coating, and the maximum peak is lower than the real mechanical properties of the in-situ TiC reinforcement due to the influence of the reinforcement size and indentation position. Under the consideration of coating microstructure and reinforcement size, by reasonably setting the fractional indentation test conditions and selecting the appropriate test area, it can reveal comprehensive properties of the coating while obtaining real mechanical properties of different phase structures of in-situ TiC composite coatings.

MXene (Ti3C2Tx) is a promising electrode material for supercapacitors. However, the current MXene material preparation process often requires hydrofluoric acid, and the etched MXene is easily oxidized and stacked, which is not conducive to the transfer of electrons and ions. In this study, we proposed a high concentration of sodium hydroxide solution mixed with sodium hypochlorite solution as an etchant for the preparation of fluorine-free MXene (Ti3C2Tx). Based on the alkali-assisted hydrothermal method, Ti3AlC2 was used as the raw material, and 10 % NaClO aqueous solution was added as the oxidant during the etching process to accelerate the etching and in-situ generate TiO2 with excellent conductivity. When the oxidation time is 12 h and the amount of NaClO is 0.2 mL, the TiO2 particles in-situ generated by the oxidation of Ti element in MXene are evenly distributed on the surface and interlayer of the material, which effectively curbs the stacking problem between the Ti3C2Tx layers and improves the specific surface area of the material. The prepared MXene/TiO2 electrode in 1 M H2SO4 electrolyte, − 0.5–0.2 V voltage window, the highest mass specific capacity can reach 321F/g, and after 10,000 charge–discharge cycles, the capacitance retention rate can still reach 86.4 %, which is higher than the capacitance retention rate of Ti3C2Tx material (81.7 %).

Sensible thermal storage ceramics in the form of the fluid-bed show good competency on dealing with the intermittency of renewable energy and improving energy utilization efficiency by integration the functions of thermal absorption and storage. In-situ nano-sized β-Sialon whiskers reinforced Al2O3-based ceramic materials for fluid-bed thermal storage system were one-step synthesized by aluminothermic reduction method, using solid waste coal-series kaolin and Al powder as main raw materials and firing at 1500 °C in N2 atmosphere. The effects of Al content and firing temperature on phase evolution, microstructure and properties of fired samples were researched by XRD, SEM, TEM, etc. The results showed that nano-sized β-Sialon whiskers could be in-situ synthesized at 1300 °C, which effectively enhanced the bending strength of fired samples. The highest β-Sialon content and the optimal properties could be achieved at 1500 °C while coal-series kaolin and Al mass ratio was equal to 70∶30, which were listed as follows: 30.7 % β-Sialon content, 74.9 MPa high-temperature bending strength (at 1400 °C), 6.17 × 10-6·°C-1 thermal expansion coefficient (room temperature-1000 °C), 0.74 J·(g·K)-1 specific heat capacity (at room temperature), 873.90 kJ·kg-1 theoretical thermal storage density (ΔT=900 °C), which is suitable as the thermal storage material for the fluid-bed thermal storage system.

The nanofiltration membranes with a stable decoration of inorganic fillers such as zeolites are desperately required for enhancing the desalination performance of the membranes and hence three nanofiltration membranes were fabricated by decorating the membranes with praseodymium-based triamino-functionalized MCM-41 (Pr-(NH)2NH2-MCM-41). The membranes were applied for the removal of emerging pharmaceutically active micropollutants from water. The Pr-(NH)2NH2-MCM-41 was synthesized by using an in-situ approach where praseodymium oxide was chemically decorated in the framework of MCM-41 followed by simultaneous amine functionalization using N1-(3-Trimethoxysilylpropyl)diethylenetriamine (TMSPTA). A thorough characterization of the synthesized Pr-(NH)2NH2-MCM-41 was carried out by using HR-TEM, SEM, WCA, XRD, FTIR, BET, elemental and mapping analysis. Three different concentrations of synthesized Pr-(NH)2NH2-MCM-41 were decorated in the membrane active layer through interfacial polymerization in the presence of an aqueous tetra-amine solution and using terephthaloyl chloride as an organic crosslinker. Subsequently, the fabricated membranes were used for desalinating saline feed containing divalent (CaCl2, MgCl2, Na2SO4, MgSO4) and monovalent (NaCl) ions. The rejection of salts by PA/0.05-Pr-MCM@PSU/PET membrane was found to be the highest among all the fabricated membranes which were found to be 98 %, 96 %, 95 %, 87 %, and 82 % for CaCl2, MgCl2, MgSO4, Na2SO4 and NaCl, respectively. The permeate flux was found to be dependent on the applied feed pressure which was found to be 56 L m-2 h-1 (LMH) at 25 bar for PA/0.050-Pr-MCM@PSU/PET membrane. The rejection performance of the membranes was also evaluated by using different well-known pharmaceuticals (Caffeine, Sulfamethoxazole, Amitriptyline, and Loperamide) as micropollutants in the feed. All the pharmaceutical drugs were found to be highly rejected > 96 % by PA/0.5-Pr-MCM-41@PSU/PET membrane followed by PA/0.025-Pr-MCM-41@PSU/PET membrane. Therefore, the current approach of synthesizing functionalized zeolites is quite effective and efficient for the stable decoration of inorganic fillers in the membrane active layer and should be extended to other zeolites such as zeolites with antimicrobial potential.

Nowadays, the increasingly severe electromagnetic (EM) wave pollution requires high-performance EM wave absorbing materials. Multi-principal-element materials are acknowledged as promising for broadening the applications owing to their tunable chemistries and structures in many fields, including as EM wave absorbers. Herein, we prepared a high-entropy MXene, (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25) 3 C 2 T x. Furthermore, multi-principal-element (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25) 3 C 2 T x /FeCoNi and (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25) 3 C 2 T x /FeCoNiCu composites were synthesized via an in-situ hydrothermal process by combining high-entropy MXene with medium-entropy magnetic alloys. In contrast with the relatively narrow effective absorption bandwidth (EAB) of (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25) 3 C 2 T x MXene (2.56 GHz), (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25) 3 C 2 T x /FeCoNi composite with 50 wt% MXene can attain an optimum EAB of 4.88 GHz with the matching thickness of only 1.73 mm. As for (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25) 3 C 2 T x /FeCoNiCu composites, both the absorption efficiency and absorption bandwidth are significantly enhanced. The combination of multi-principal-component strategy and composite construction endows the composites with synergistic dielectric and magnetic losses, optimized impedance matching as well as enhanced attenuation ability, thus improving EM wave absorption performances. In addition, radar cross section (RCS) simulation confirms that the prepared composites have broad application prospects as radar stealth materials. [ABSTRACT FROM AUTHOR]

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

We developed a simple method of in-situ synthesize carbon nanotubes (CNTs) on Ti–6Al–4V (TC4) alloy powder to fabricate CNTs/TC4 compound powders through plasma-enhanced chemical vapor deposition (PECVD). By this approach, CNTs on TC4 alloy powder exhibit better uniform dispersion and morphology compared with the traditional CVD methods. In order to reveal the growth behavior of CNTs during the PECVD process, XRD, SEM, TEM, and Raman spectroscopy were used to analyze the morphology and graphitization of CNTs at different synthesis conditions. The plasma is benefit to the pyrolysis of CH4, but overmuch plasma bombardment also reduces the yield and quality of CNTs. The number of CNTs can be significantly improved with appropriately increasing the temperature and time, but excessive temperature, time and carbon concentration can increase the number of impurities such as amorphous carbon. Significantly, the growth mechanism of CNTs synthesized in TC4 powders is following tip-growth mode in PECVD process. Additionally, the quantity and quality were satisfactory at 600 °C for 30 min with 50 W plasma power. This study about PECVD process lays a foundation for improving the comprehensive properties of CNTs/TC4 composites in the future.

Porous mullite-based ceramics have been developed using a mixture of zeolite-poor rock and alumina through mechanical activation and reactive sintering. The experimental findings demonstrate that the in-situ mullite growth may develop in a variety of shapes, including whiskers, nanofiber, nanonetwork and diamond-like particles. The XRD examination indicates that the samples sintered at 1500 °C are mostly made of the mullite phase. The SEM photographs show that as the sintering temperature increases, the mullitization process takes place first in zeolite-poor rock particles, and subsequently, alumina combines with the silica-containing phase via a liquid-phase sintering mechanism to produce an interlocking network of extended secondary mullite. The effects of mullite formation and the sintering temperature on various properties of the sintered samples, such as their density, apparent porosity, thermal conductivity, strength, wear resistance, composition, morphologies, and microstructural characteristics of the sintered samples were studied. Increasing the sintering temperature from 1100 to 1500 °C improved the different properties. The density increased from 1.9 to 2.1 g/cm3, thermal conductivity rose from 0.9 to 1.6 W/m.K, compressive strength escalated from 18.9 to 92.1 MPa, and worn material volume decreased from 2444 to 36.9 mm3 after a 5-min abrasion test.

Cr(III) was adsorbed and separated by activated carbon (AC) from aqueous solution in order to recycle and reuse it, then MIL-101(Cr)/AC composite was in-situ synthesized by hydrothermal method based on AC adsorbed Cr(III). The structure and morphology of AC, MIL-101(Cr) and MIL-101(Cr)/AC composite were investigated by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller and zeta potential. The factors of time, temperature, pH and adsorbent dosage on Cr(VI) adsorption capacity and the reusability of the materials were studied. The results indicated that the specific surface area of AC, MIL-101(Cr) and MIL-101(Cr)/AC was 950.9, 1,687.1 and 655.9 m²·g-1, respectively. The adsorption capacity of MIL-101(Cr)/AC for Cr(VI) was 47.00 mg·g-1, which was higher than that of AC (45.22 mg·g-1) but less than that of MIL-101(Cr) (50.5 mg·g-1). The adsorption of Cr(VI) on MIL-101(Cr)/AC is a spontaneous exothermic process and best fitted with the second-order kinetic model and Langmuir isotherm model. The composite of MIL-101(Cr)/AC, is a green adsorbent and shows good reusability for Cr(VI) removal from water. [ABSTRACT FROM AUTHOR]

LDH@ZIF-8 composite has been synthesized via in-situ growth of zeolitic imidazolate frameworks-8 (ZIF-8) on Zn/Al hydrotalcite. The morphology and composition of the samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscope and N2 adsorption-desorption technics. The adsorption performances of LDH@ZIF-8 sample for phthalic acid were investigated. The results show that the adsorption capacity of LDH@ZIF-8 could be as high as 508.72 mg/g at 20°C, C0 = 100 mg/g. The adsorption isotherms and adsorption kinetics were well described by Freundlich isotherm model and the pseudo-first-order kinetic equation, respectively. In addition, recycling experiments revealed that the behavior of LDH@ZIF-8 is maintained after recycling for at least three times. [ABSTRACT FROM AUTHOR]

The high temperature oxidation behavior of plasma sprayed chromium boride-chromium carbide composite coatings had been studied in this work. In-situ and ex-situ CrB 2 -Cr 3 C 2 composite coatings were prepared by plasma spraying Cr-B 4 C and CrB 2 -Cr 3 C 2 composite powders, respectively. The changes of microstructure and phase of two coatings after oxidation at different temperature and time were studied. After oxidation at 850 °C for 10 h, the in-situ Cr-B 4 C coating had a thinner oxide layer (8–10 μm) and a lower weight gain rate (0.023%) than ex-situ CrB 2 -Cr 3 C 2 coating. This is because the density of Cr-B 4 C coating was high, and the oxidized glass phase B 2 O 3 gradually filled the pores of the coating at 850 °C. For oxidation of CrB 2 -Cr 3 C 2 coating at 1000 °C for 10 h, since the evaporation rate was higher than the generation rate of liquid oxide layers, a large penetration cracks damaged the integrity of the coating surface, which would not hinder oxygen into the coating. The Cr-B 4 C coating had better oxidation resistance after oxidation at 1000 °C for 10 h, because more phases with low oxygen permeability were formed in the coating, and the generation rate of the oxide film was higher than the evaporation rate. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering 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.)