CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Wenyan Huang,Yufeng Wang,Zhonghao Ning,Shengjian Mao,Zhichao Xue,Yeqi Zhu,Qianwen Tao,Siqi Lan,Rongqian Yao
Making lightweight SiC composite ceramics with good load-bearing and remarkable surficial antioxidant capacity for use in thermal protection system is challenging. In this contribution, an ingenious strategy is reported to produce SiC(Mo x , rGO) nanocomposite polymer-derived ceramics (PDCs) for the first time by reactively re-pyrolyzing flexible polymolybdenumcarbosilane-vinyltriethoxysilane-graphene oxide (PMVG)/rigid SiC(Mo x , rGO) p fillers blends. Highly cross-linked PMVG precursors connect up to five polycarbosilane (PCS) to optimize their formability. In-situ formed MoSi 2 and Mo 4.8 Si 3 C 0.6 , compatible with β-SiC/SiO x C y /C free (rGO) matrix, can effectively strengthen interface bonding, promote nailing cracks, and even hinder β-SiC grain growth. More interestingly, using in-situ SiC nanowires (SiC nws ) by Mo-containing catalyst to decorate samples is an efficient route to reinforce the ceramic network, and SiC nws /SiC(Mo 0.1 , rGO) nanocomposite PDCs display optimal Vickers hardness (5.19 GPa), enhanced fracture toughness (4.26 MPa·m 1/2 ), high compressive strength (151.73 MPa), and low linear shrinkage (4.75%). Such products remain stability/integrity under flame scouring, their surface is covered by a dense SiO 2 passivation layer with good self-healing capacity owing to unique non-destructive oxides of embedded MoSi 2 /Mo 4.8 Si 3 C 0.6 . This work can further provide a feasible way to overcome the critical fabrication process in lightweight porous PDCs with well-balanced high load-bearing and good thermal insulation integration for aerospace vehicle components.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Wei Shi,Xiaojing Liu,Yulei Liu,Dong Li,Xili Tong,Jun Ma,Lu Wang
Development of robust, reactive, and inexpensive catalyst for pollutants abatement with catalytic ozonation is of great significance. Herein, the effect of a robust and easy-recovery catalyst, Fe 2 O 3 /Al 2 O 3 -SiC, for the catalytic ozonation of hardly biodegradable COD (hard COD) in coking wastewater had been explored. Al-O-Si bond formed on modified SiC through the substitution of hydrogen in surficial Si-OH groups by Al 3+ . The Lewis acid sites improved the adsorption of ozone and facilitated the formation of ·OH and O 2 · − . For coking wastewater treatment , the removal ratio of hard COD and the generation speed of hydroxyl radical (R ct ) in the catalytic ozonation process were 71% and 253% higher than those in the ozonation group, respectively. Ozone utilization increased from 0.44 g COD removed/g O 3 in the ozonation group to 1.42 g COD removed/g O 3 in the Fe 2 O 3 /Al 2 O 3 -SiC catalytic ozonation group. In a full-scale application, Fe 2 O 3 /Al 2 O 3 -SiC catalytic ozonation decreased the consumption of O 3 to 60 mg L −1 and decreased the operation cost by 50%. These results provided an approachable way for sharing the extraordinary capacity of ozone for contaminants remediation in industrial applications.
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DOI
PubMed
高影响因子
Materials Today Physics
·
2022
·
IF 11.021
Hua He,Wei Huang,Zhiguang Guo
Facing the problems of fossil energy shortage and solid surface icing, the use of solar energy to remove surface ice accumulation is a promising solution. Here, we propose a superhydrophobic coating with a photothermal effect for anti-icing and de-icing and defrosting performance. We designed the coating using a simple secondary spray method. That is, a bonding substrate (epoxy resin) is first constructed on the glass substrate , then a protective layer (polydimethylsiloxane(PDMS)) mixed with SiC/TiN composite particles is sprayed onto the epoxy resin surface, and finally dried to obtain a photothermal superhydrophobic coating. In this design, the coating shows (I) excellent superhydrophobicity (water contact angle = 155°, sliding angle = 4°), (II) excellent photothermal effect (the surface temperature of obtain coating rapidly rose to 111.8 °C under 1 sun), and (III) good chemical and mechanical stability. As a result, the coating shows excellent anti-icing, de-icing, and defrosting properties. For example, the coating can significantly extend the icing time. In the face of surface frozen water droplets, frost layers, and large areas of ice cover, the coating can rapidly photothermally remove surface ice layers under 40 mW cm −2 light irradiation. As a result, the coating is simple to prepare and has excellent superhydrophobic, photothermal anti-icing/de-icing, and defrosting properties. The study is of great significance for multifunctional applications.
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高影响因子
MATERIALS CHARACTERIZATION
·
2023
·
IF 4.7
Hui Zhu,Bo Liu,Ling Wu,Ye Cong,Zhijun Dong,Jianguang Guo,Baoliu Li,Xuanke Li
The in-suit synthesis of SiC nanowires (SiCNWs) on carbon fibers (CFs) to produce SiC@C composites is pivotal due to their broad applications. However, it's challenging because most CFs have a microstructure unsuitable for SiCNWs nucleation. In this study, we introduced a series of carbide coatings on CFs to facilitate the growth of SiCNWs through a thermal evaporation process. It was observed that carbide coatings on CFs significantly enhance the nucleation of SiC, enabling the efficient production of SiCNWs@CF. These SiCNWs can grow directly on the carbide-coated CFs through heteroepitaxial nucleation. Carbide coatings with a cubic phase structure and a crystalline size of less than 50 nm are vital for SiCNWs formation. This carbides coating approach is beneficial not only for carbon materials but also holds potential for numerous other matrices.
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高影响因子
PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY
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2022
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IF 3.315
Da Hu,Jiabin Lu,Jiayun Deng,Qiusheng Yan,Haotian Long,Yingrong Luo
Magnetic particles (Fe 3 O 4 /CIP) in magnetorheological elastomer (MRE) were used as solid-phase catalysts in the heterogeneous Fenton reaction for chemical mechanical polishing (CMP) of single-crystal SiC. The polishing effect and polishing mechanism were investigated by experiments and polishing debris analysis. The results show that when using H 2 O 2 polishing solution the material removal rate (MRR) was higher and the surface roughness (Ra) was lower at all stages of polishing than using deionized water polishing solution. The MRRs when polishing for 60 min with the deionized water and the H 2 O 2 polishing debris were, respectively, 636.94 nm/h and 1194.27 nm/h (an increase by 87.5%), and the corresponding Ra values were, respectively, 12.445 nm and 4.420 nm (a decrease by 64.5%). From the analysis of the polishing debris after 60 min of polishing, it was found that the H 2 O 2 polishing solution was polished with laminated loose chips, and the main elements of the chips were C, O, and Si, with O element accounting for 38.585 wt%. This indicates that a chemical reaction has occurred on the SiC surface during polishing, generating low hardness and low binding strength SiO 2 , and thus resulting in increased material removal; this phenomenon is confirmed by the profile morphology of SiC wafer by fixed-point polishing. It is shown that the use of Fe 3 O 4 /CIP in MRE as a solid-phase catalyst for the heterogeneous Fenton reaction of polishing SiC can substantially increase the material removal capacity of MRE polishing pads and improve the polishing quality at the same time.
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高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 20
·期 2
·1090-1102
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IF 2.328
Fen Li,Hanzi Du,Ting Chen,Qikun Zhu,Zhaoju Yu
For the first time, the present work reports the dielectric properties and electromagnetic wave (EMW) absorbing performance of polymer-derived carbon-rich NbC-SiC-C nanocomposites. In our previous work, NbC-SiC-C nanocomposites with the ultra-high temperature ceramic phase NbC as the main phase were synthesized with the allylhydridopolycarbosilane (AHPCS) and niobium pentachloride (NbCl 5 ) as starting materials. On this basis, divinyl benzene was chosen as carbon-rich source and introduced into the AHPCS and NbCl 5 to form a single-source-precursor. Finally, carbon-rich NbC-SiC-C nanocomposites were successfully synthesized by polymer-derived ceramic approach. Compared with ceramic samples without Nb and with lower carbon content, the carbon-rich NbC-SiC-C nanocomposites show extremely enhanced EMW absorbing performance with minimum reflection coefficient of −51.1 dB at 6.88 GHz for the thickness of 2.27 mm. As a consequence, the resultant carbon-rich NbC-SiC-C nanocomposite has to be considered as structure&function integrated material with excellent EMW absorption performance, which can be applied in hostile environment.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Wentian Gan,Xiangjun Guo,Yun Huang,Xianqing Zhu,Ao Xia,Xun Zhu,Qiang Liao
Biofilm with high biomass density and high gas–liquid mass transfer efficiency is one of the most efficient bacterial culture modes for ethanol fermentation using CO/ CO 2 gas. However, it is very difficult and requires a long time for bacteria to form a stable biofilm due to the weak adhesion ability between bacterial cells and the substrate. To synergistically enhance bacterial adhesion during biofilm formation and biofilm detachment after fermentation to reuse the substrate, a substrate surface with controllable properties is expected. Thus, in this study, a temperature responsive substrate was prepared by grafting a thermosensitive hydrogel of N -isopropylacrylamide onto the surface of a silicon carbide (SiC) substrate to accelerate the formation of biofilm. The hydrophobicity of the modified substrate surface changed from 52.6° to 89.4° as the temperature increased from 25 °C to 37 °C (the optimal cell culture temperature). The adhesion free energy between the bacterial biofilm and the substrate changed from −4.11 MJ m −2 to −41.7 MJ m −2 , indicating a stronger adsorption capacity. Moreover, the surface zeta potential increased from −7.7 mV to +7.6 mV, forming an electrostatic attraction between the cell (-27 mV) instead of electrostatic repulsion force. All the above making the bacteria easier adhere and forming biofilm faster. Compared with that on the original SiC substrate, the bacterial biofilm-forming rate was increased by 6.2 times, which shortened the stable biofilm-forming time to 4 days. The mean ethanol productivity was 0.54 g/L d -1 , 116 % higher than that on the original SiC substrate. Therefore, controlling bacterial adhesion on the temperature responsive substrate was an efficient way to enhance ethanol production by CO/CO 2 fermentation.
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Haochen Qi,Chuang Xing,Weiguo Huang,Mingquan Li,Yujia Jiang,Xu Sun,Heyang Liu,Peng Lu,Jiangang Chen,Shuyao Chen
Fischer-Tropsch (FT) synthesis as a strongly exothermic reaction has diffusely manufactured clean fuels from syngas. However, it is difficult to obtain the concentrated product distributions. Here, we design ZSM-5 encapsulated cobalt particles on the thermal conductivity of the SiC matrix. The Co@NaZSM-5/SiC capsule catalyst with hierarchical structure is ingeniously assembled through a solvent-free synthesis route. Due to the joint functions of acidic zeolite , SiC thermal conductivity and macropores, the olefin selectivity enhances to 32.3% on the Co@NaZSM-5/SiC catalyst. Moreover, the ratio of O 5-11 /C 5-11 approaches 49.1% suggesting the elevated middle olefin proportion. The H + ion-exchanged Co@HZSM-5/SiC capsule catalyst shows a high isoparaffin selectivity of 27.3%, since the olefin isomerization reaction is accelerated over strong acid sites. Besides, Co 2 C phase is readily formed during the FT reaction, which is an activity center for olefin synthesis. The capsule catalyst with the proper acidity, thermal conductivity, and hierarchical structure is a promising prospect for tuning production distribution in FT reaction.
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高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 19
·期 4
·2083-2092
·
IF 2.328
Zixuan Chang,Zihe Li,Xinran Liu,Xu Zhang,Shikang Xiao,Yuhang Tian,Aijun Li,Jingde Zhang,Jianzhang Li,Guifang Han
Mullite-bonded porous SiC ceramics sintered in air by gelcasting are still challenges due to the high porosity induced severe oxidation of SiC, which results in the formation of large amount of detrimental cristobalite phase. Here in this work, small amounts of Y 2 O 3 and CaF 2 were added in SiC and Al(OH) 3 raw materials as sintering additives for the in situ growth of mullite reinforcement. This additive system promoted the reaction between oxidation-derived SiO 2 from SiC and Al 2 O 3 decomposed from Al(OH) 3 to mullite phase. Almost no cristobalite phase was detected when sintered at 1450℃/2 h with CaF 2 addition of more than 2.0 wt%. Mullite whisker reinforcement was in situ formed due to the gas reaction mechanism caused by CaF 2 addition. Thus obtained porous SiC ceramics exhibited a flexural strength of 67.6 MPa at porosity of 41.3%, which maintained exceeding 36 MPa after 8 h corrosion in 10 wt% NaOH 80℃ solution, being the best performance up to now. This high performance of porous SiC was attributed to the additive induces proper phase control and in situ formation of whisker-like mullite reinforcement.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Yaxiong Liu,Yehong Cheng,Denghao Ma,Ning Hu,Wenbo Han,Dazhao Liu,Shuai Wu,Yumin An,Anzhe Wang
As one of additive manufacturing techniques, direct ink writing has significant advantages in the manufacture of ceramic matrix composites , nevertheless, the poor impregnability of ceramic slurry makes it difficult to fill the interior of fiber bundles, causing poor mechanical properties . Here, ultrasound-assisted fiber separation technique was introduced to impregnate ceramic slurry with a continuous carbon fiber bundle during direct ink writing of continuous carbon fiber/ceramic green body and subsequent low temperature hot-pressing was combined to improve its robustness. Suitable thickness of carbon coating could bring to high fracture resistance, whereas excessively thick carbon coating will adversely affect the mechanical properties. A carbon interface with thickness around 110 nm was incorporated, the flexural strength , fracture toughness and work of fracture of C f /ZrB 2 -SiC composite reached 388.3 MPa, 10.04 MPa·m 1/2 and 2380 J/m 2 , respectively. Therefore, direct ink writing combined with low temperature hot-pressing, was effective to fabricate high-performance ceramic matrix composites.
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高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2022
·
IF 9.463
Limeng Song,Yongqiang Chen,Qiancheng Gao,Zhe Li,Xinyue Zhang,Hailong Wang,Li Guan,Zhaoju Yu,Rui Zhang,Bingbing Fan
With the rapid development of modern information technology, high-level electromagnetic wave (EMW) absorbing materials are playing an increasingly important role in military and civilian fields. However, current EMW absorbers usually have narrow absorption bandwidths and low absorption strengths , which hinder their practical applications. Herein, lightweight aerogels with low thermal conductivity and highly efficient EMW absorption were fabricated via a sol–gel method and subsequent carbothermal reduction with a simple chemical reaction process. The as-prepared graphene/SiC-nanosheets aerogels are composed of a large number of the interconnected two-dimensional SiC nanosheets and graphene sheets with abundant micrometer-sized pores that favored impedance matching, which endows the aerogels with outstanding EMW-absorbing performance. Conductive loss and interfacial polarization further promote the EMW-absorbing of the graphene/SiC-nanosheets aerogels. In addition, the highly porous and interconnected three-dimensional graphene/SiC-nanosheets aerogel networks not only facilitate the absorption of infiltrated EM waves via multiple reflection but also effectively reduce the number of heat transmission routes in the aerogels. The as-prepared SiC/G-2 aerogel exhibites excellent EMW-absorbing property, with a RL min of −65.08 dB at a frequency of 13.20 GHz, a thickness of 3.5 mm and an EAB of 2.21 GHz. These results demonstrate that the as-prepared graphene/SiC-nanosheets aerogel is fascinating material with possible applications in high-performance EMW-absorbing and heat-insulating in the aviation and aerospace fields.
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高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jiuhong Ma,Huizhong Zhao,Jun Yu,Han Zhang,Yichong Li,Lida Shi,Yi Zhao,Jian He
In this study, four types of commercial tabular corundum were selected as aggregates, and four Al 2 O 3 –SiC–C castables were prepared under same conditions. The microstructure characteristics of the aggregates were observed. The thermal shock resistance and slag resistance mechanism were evaluated. Dendritic pores were proven to be beneficial for relieving and guiding thermal stress. According to the Lobe method, the dendritic pores provided the aggregates with a higher thermal conductivity and better thermal stability than the circular pores. The role of the aggregate microstructure in resisting slag erosion was discussed through thermodynamic and kinetic analyses. The presence of dendritic pores and a small neck size led to a faster dissolution rate during the slag erosion process. At the same time, the dissolution rate and dissolution amount increased, resulting in the faster supersaturation of the slag. Based on Ostwald's supersaturation theory, a thicker spinel isolation layer would be precipitated on the inner walls of the slag erosion path, thereby preventing the further erosion of the slag.
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高影响因子
危险品化学品经营许可证（带存储）