Materials Today Communications
·
2024
·
IF 3.7
Q. Li,J. Shang
Al 2 O 3 /MoS 2 /CePO 4 composite ceramic layer was in-situ prepared on aluminum alloy by micro-arc oxidation. The results show that the content of (CH 3 CO 3 ) 3 Ce·xH 2 O has a great influence on the microstructure of the ceramic layer. When the addition amount is 7.5 g/L, the surface hardness of the ceramic layer is 961.97 HV 1 , which is 1.8 times that of the unadded and 8.36 times that of the matrix. Tribological tests show that the moderate addition of (CH 3 CO 3 ) 3 Ce·xH 2 O also significantly improves the wear resistance of the ceramic layer. Composite layer research can be developed and applied to other alloys to improve their friction properties.
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DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Shuisen He,Xueman Wang,Chenglong Wen,Yu Fan
A novel (C 11 H 26 N) 2 Co(MoS 4 ) 2 complex was prepared via the n-octyltrimethylammonium bromide-assisted self-assembly of CoMo precursors for the selective hydrodesulfurization (HDS) of thiophene. The complex was generated by the interaction between the negatively charged CoMo compound and the positively charged n-octyltrimethylammonium ions. Then positively charged bimolecular layers were formed owing to van der Waals forces between the C 11 H 26 N + and the complex, and they were anchored on the negatively charged γ-Al 2 O 3 . Compared with CoMoS/γ-Al 2 O 3 catalysts prepared by impregnation, the optimal CoMoN-0.3/γ-Al 2 O 3 catalyst exhibited better performance for selective HDS due to the enhanced Mo dispersion, the close contact between Co and Mo, and the increased amount of CoMoS phases on γ-Al 2 O 3 . Among these catalysts, the optimal CoMoN-0.3/γ-Al 2 O 3 catalyst with the highest concentration of CoMoS phases exhibited the highest HDS reaction rate constant of 6.95 × 10 -6 mol·g −1 ·s −1 and the best selective factor of 26.1 for the selective HDS of thiophene with 1-hexene.
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高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Gaohong Wu,Xiangjia Sun,Yanrong Liang,Jiaying Zheng,Yulan Xie,Zhaoping Chen,Jian Xu,Weidong Xiang,Xiaojuan Liang
To address the thermal management challenge in phosphor-in-glass (PiG) materials for laser lighting due to low glass matrix thermal conductivity, this study developed YAG:Ce 3+ -Al 2 O 3 PiG composites reinforced with Al 2 O 3 particles, achieving a thermal conductivity of 78.6 W/(m·K). A TiO 2 reflective layer optimized for reflection and light conversion was introduced between the AlN substrate and PiG layer. Systematic optimization of Al 2 O 3 content and preparation conditions yielded YAG:Ce 3+ -Al 2 O 3 PiG composites with exceptional performance: maximum luminous flux (LF) of 2515 lm under blue laser excitation, saturation threshold (ST) of 27.57 W/mm 2 , and luminous efficiency (LE) of 174.7 lm/W. LF and ST increased by 184.5 % and 167.4 %, respectively, compared to non-Al 2 O 3 counterparts. The surface temperature of 9 wt% Al 2 O 3 PiG reached 363.85 K, 34.4 % lower than the working temperature of the sample without Al 2 O 3 addition. Stable light emission and high photothermal stability confirm its potential as a high-brightness laser lighting material.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Han Xu,Gangsong Huang,Wenting Zhou,Xuan Miao,Hongjun Ji,Mingyu Li,Yufeng Li
In the realm of electronic packaging advancements, the utilization of metal to ceramic joints has garnered significant attention. This manuscript details the development of a specific glass solder with excellent wettability and a thermal expansion coefficient of 8.1 × 10 −6 °C −1 , comprising 35Bi 2 O 3 -30B 2 O 3 -15ZnO-20SiO 2 (mol.%). This design achieves reliable connection of the Al 2 O 3 ceramics and Kovar alloy in an atmospheric environment. The interface reaction between the glass solder, Al 2 O 3 ceramics, and oxidized Kovar alloy resulted in the formation of ZnAl 2 O 4 particles and Bi spheres at the joints. The enhancement in joint shear strength was primarily attributed to the nanoscale, dispersed ZnAl 2 O 4 particles. However, the presence of microscale Bi spheres, with a lower elastic modulus than the glass solder, initiated cracks during shear deformation, thereby compromising the integrity of the joint. Optimization of brazing temperatures enabled control over the ZnAl 2 O 4 and Bi sphere phases within the joints, yielding a peak shear strength of 51.7 ± 8.9 MPa at 650 °C. This study highlights the achievement of high-performance metal-ceramic bonding through tailored interface reactions and optimized joint microstructures.
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DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2024
·
IF 3.9
Lihan Deng,Jin Li,Jiachen Chen,Jin He
Nanoporous Al 2 O 3 -SiO 2 glasses were prepared using a sol–gel method. These sintered nanoporous Al 2 O 3 -SiO 2 glasses have a transmittance greater than 85 % and possess high mechanical strength, enabling them to contain and protect RE ions. Owing to the presence of nanopores in nanoporous Al 2 O 3 -SiO 2 glasses, Eu ions can easily enter the nanoporous Al 2 O 3 -SiO 2 glasses via an ex-situ dipping method. After drying at room temperature (RT) and then heating at 400 °C, 600 °C, 800 °C, and 1200 °C, we obtained a series of Eu doped nanoporous Al 2 O 3 -SiO 2 glasses. The thermal reduction process from Eu 3+ ions to Eu 2+ ions can occur at a lower sintering temperature (400 °C), enabling a detailed analysis of the thermal reduction mechanism at both low and high temperatures in detail. Under the conditions where Al 3+ ions are present in the samples that are under calcination, Eu 2+ -doped nanoporous Al 2 O 3 -SiO 2 glasses are more easily obtained at relatively low temperatures. Owing to the adjustable composition of Eu 3+ /Eu 2+ in the nanoporous Al 2 O 3 -SiO 2 glasses, tunable emission from red-orange light to blue-violet light can be achieved in the samples. This new type of transparent Eu-doped NPGs has the advantages of high mechanical strength and good processability and is non-toxic and harmless, thereby showing great potential for use in tunable light sources and LED devices.
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高影响因子
JOURNAL OF FLUORINE CHEMISTRY
·
2024
·
IF 1.7
Xiaoli Wei,Yiwei Sun,Jianhai Jiang,Zhen Wang,Wei Zhang,Bing Liu,Shucheng Wang,Xiaodan Yang,Wanjin Yu,Jianjun Zhang,Wenfeng Han
Al 2 O 3 exhibits high activity for the resource utilization of potent greenhouse gases, hydrofluorocarbons via dehydrofluorination or F/Cl exchange. However, it experiences completely fluorination under corrosive HF environment, leading to thorough fluorination of F-Al-O active site into F-Al-F, accompanied with serious carbon deposition. In this work, we successfully confined Al 2 O 3 in SiC (Al 2 O 3 @SiC) via treating Al 2 O 3 /SiC under high temperatures (>800 °C). The results showed that different with simple loaded Al 2 O 3 (Al 2 O 3 /SiC), during high temperature treatment, reaction between Al 2 O 3 and SiC occurred, leading to the confinement effect. Then, contributed by the interaction, desired F-Al-O species could be stabilized on the surface of SiC. While for Al 2 O 3 /SiC, it thoroughly turned into AlF 3 under identical reactive conditions, leading to inferior stability during CH 3 CHF 2 dehydrofluorination. Furthermore, the reaction rate of 5 %Al 2 O 3 @SiC is nearly up to 4 folds higher than that of traditional AlF 3 . Facilitated by the suitable Lewis acid intensity, less carbon deposition formed on Al 2 O 3 @SiC. Thus, constructing strong interaction between F-Al-O and stable SiC provides a potential strategy to stabilize unstable active centers.
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高影响因子
Advanced Composites and Hybrid Materials
·
2025
·Vol. 8
·期 6
·451
·
IF 21.8
Chen Yanan,Ge Sijia,Li Hong,Liu Ling,Hu Xueyan,Hu Peiying,Wu Xiaodong,Cui Sheng,Wang Jin
Aramid nanofiber (ANF) aerogels possess excellent flexibility and favorable mechanical properties. However, their limited infrared transmittance, relatively high thermal conductivity, and low flame retardancy significantly restrict their application in passive thermal management. In this study, a microphase separation strategy is employed to fabricate ANF@Al 2 O 3 composite aerogels, enabling a structural transition from a uniform-pore to a slit-pore morphology. Benefiting from the light regulation by the slit pore structure and the flame-retardant effect of Al 2 O 3 , the prepared ANF@Al 2 O 3 aerogels material have ultra-low thermal conductivity (as low as 30 mW/(m·K)), high infrared transmittance (near-infrared transmittance > 90%), and excellent fire resistance (enhanced combustion endurance), which is able to meet the various needs of passive heating in intelligent buildings. Under outdoor solar irradiation (29.3 °C, 677.6 W/m 2 ), the ANF@Al 2 O 3 composite aerogel achieves an internal temperature of 50.46 °C, achieving a relative heating enhancement of 72.22%. This study provides a strategy for designing high-performance composite aramid aerogels and holds great promise for mild thermal insulation applications with potential relevance to aerospace, energy-efficient buildings, and smart thermal management systems. Graphical
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高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Shaopeng Li,Weichao Li,Yun Wu,Xianming Zheng,Xuehui Zhao,Ning Nan,Hongwei Zhang
The performance of supported catalysts is significantly affected by the dispersion degree of the active components on the support. In this study, citric acid (CA) was used as a modifier to prepare Al 2 O 3 supported Mn-Ce oxides (Mn-Ce/CA-Al 2 O 3 ) by the impregnation-calcination method. The characterization results showed that adding citric acid enhanced the dispersion of Mn-Ce oxides on the support, rendering Mn-Ce/CA-Al 2 O 3 with a larger specific surface area and abundant surface hydroxyl groups, thereby providing more reaction sites for catalytic ozonation. The Mn-Ce/CA-Al 2 O 3 exhibited excellent catalytic ozonation performance in degrading Reactive Black 5 (RB5) dye. It achieved nearly complete decolorization of RB5 within 60 min, with a COD removal efficiency of 60%, which was superior to the sole ozonation (30%). Furthermore, the Mn-Ce/CA-Al 2 O 3 system demonstrated significant degradation of RB5 over a wide pH range of 3–11. Based on the XPS and EPR analysis results, a preliminary mechanism of catalytic ozonation over the Mn-Ce/CA-Al 2 O 3 was proposed. The redox cycle of Mn 3+ /Mn 4+ and Ce 3+ /Ce 4+ effectively accelerated the electron transfer process, thus promoting the generation of reactive oxygen species (ROS) and improving the degradation of RB5. Meanwhile, the Mn-Ce/CA-Al 2 O 3 exhibited superior catalytic stability and effective treatment capabilities for real dye wastewater.
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高影响因子
Catalysts
·
2025
·Vol. 15
·期 5
·416
·
IF 4
Jie Qin,Guohong Chen,Kaiqi Zheng,Jiajun Wu,Fanan Wang,Xueping Liu,Rengui Weng
2-Methyltetrahydrofuran (2-MTHF), a hydrogenated derivative of levulinic acid (LA), is a biomass-derived platform compound with diverse and significant applications as a biofuel, gasoline additive, green solvent, and pharmaceutical synthesis intermediate. This study investigates the preparation of a Cu1Ni2/Al2O3catalyst through the calcination–reduction of CuNiAl hydrotalcite as a precursor, which was subsequently utilized in the hydrogenation of LA to produce 2-MTHF. The calcination–reduction process applied to CuNiAl hydrotalcite results in a lattice confinement effect. This method not only disperses the active metal sites but also alters the bonding patterns of the active metals, thereby enhancing the activity and stability of the Cu1Ni2/Al2O3catalyst. The results indicate that complete conversion of LA and a 2-MTHF yield of 87.6% can be achieved under optimal conditions of 190 °C, 5 MPa hydrogen, and a reaction time of 5 h, demonstrating an efficient one-step conversion process. Additionally, the catalyst’s recyclability was assessed through multiple reuse tests, with a loss of activity of only 9.2% after six cycle experiments, suggesting its feasibility and reliability for industrial applications.
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高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2025
·
IF 6.1
Pengxing Yu,Ruoyun Wang,Kai Wang,Huabing Liu,Biyou Peng,Hongjian Huang,Junwu Xiang,Haiyang Zhou,Tong Zhou
To enhance the long-term corrosion resistance of 3D-printed AlSi10Mg alloy, this work designed a two-step micro-arc oxidation (MAO) strategy. Given the difficulty of triggering micro-arc discharge in high-Si Al alloys, an intermediate transition layer was first prepared through one-step MAO in a silicate electrolyte. Subsequently, a two-step MAO treatment was performed in a phosphate electrolyte with the addition of K 2 ZrF 6 to seal the ablation holes formed during the one-step MAO process, achieving a self-sealing effect of the MAO coating. Ultimately, a dense ZrO 2 /Al 2 O 3 ceramic coating with Si-W-Zr-P gradient distribution was obtained on the AlSi10Mg surface after the two-step MAO. Electrochemical tests reveal that the two-step MAO coating exhibits exceptional corrosion resistance, with a remarkably low corrosion current density (I corr ) of 3.42 × 10 −9 A·cm −2 , along with a protective efficiency (η p ) of up to 99.8 %. Moreover, no obvious macroscopic corrosion signs are observed on the ZrO 2 /Al 2 O 3 coating after prolonged immersion, and its I corr remains stable at 9.26 × 10 −9 A·cm −2 , indicating durable protective performance. This study offers a novel and controllable strategy for the design of anti-corrosive coatings on 3D-printed high-Si Al alloys.
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高影响因子
COMPOSITES COMMUNICATIONS
·
2020
·
IF 4.915
Dan Yang,Liyuan Yu,Jia Ai,Qungui Wei,Yufeng Ni,Liqun Zhang
With the miniaturization, integration, and functionalization of the electronic components, heat dissipation in the electronic devices has become a challenging issue. Owing to high polarity, carboxyl nitrile butadiene rubber (XNBR) is usually employed as a dielectric material in the electronic devices. However, low thermal conductivity of XNBR hardly satisfies the increasingly stricter demands for heat dissipation. Herein, we used low-cost poly(catechol/polyamine) (PCPA) to modify Al 2 O 3 nanoparticles via biomimetic method for enhancing the interfacial interaction between the Al 2 O 3 filler and XNBR. The ortho-polyphenols in catechol were oxidized into ortho-quinone groups in the alkaline solution. Then, the ortho-quinone groups formed a cross-linked structure to obtain PCPA via the Michael addition or Schiff base reaction with amine. The process decreased the interfacial thermal resistance and phonon scattering, resulting in an enhanced thermal conductivity. When the Al 2 O 3 -PCPA nanoparticles content was 30 vol%, the thermal conductivity of XNBR based composites reached up to 0.51 W/mK, which was 3.19 times that of pure XNBR (0.16 W/mK). The proposed method has potential applications in large scale production of thermally conductive composites in industries, such as electronic packaging materials and thermal management materials.
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高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2022
·
IF 4.865
Shiyu Cui,Zhou Yi,Yi Xu,Jun Huang,Jilin Xu,Junming Luo,Qiong Jiang,Jiayi Peng,Xiaoma Tao
Molybdenum disilicide (MoSi 2 ) is a novel crack-healing material used in the traditional thermal barrier coating , which reacts with ZrO 2 to attain a corresponding volume expansion of approximately 138%. However, the pre-oxidation of MoSi 2 causes the “pesting” phenomenon, which degrades the microstructure and mechanical properties throughout the service. To address this issue, the aluminum oxide was fabricated on the MoSi 2 surface using the sol-gel method and low-pressure post-heat treatment to prevent oxygen penetration. The orthogonal experiment investigated the effect of pH, temperature, and water amount on sol generation. Because the Zeta potential difference has reached its maximum value (about 27 mV) at pH 4, the aluminum sol was notably adsorbed on the MoSi 2 particles. The modified MoSi 2 @Al 2 O 3 particles were characterized to understand their morphologies, surface adsorption energy, and crystal structures. The oxygen adsorption energy on the MoSi 2 (103) surface was lower than that on the Mo 5 Si 3 (411) surface, which indicated that the oxidization process can be divided into two independent steps. The Al 2 O 3 shell was uniformly formed on the MoSi 2 particles, especially in the low-vacuum environment (10 MPa) for 3 h post-treatment. The dense core-shell structure can prevent oxygen penetration into the MoSi 2 surface, thus prolonging the self-healing property of MoSi 2 .
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高影响因子
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