JOURNAL OF MEMBRANE SCIENCE
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2020
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IF 7.183
Wenyan He,Ruiqing Lu,Kuo Fang,Erfu San,Hui Gong,Kaijun Wang
To achieve ammonium recovery and organic matter enrichment simultaneously, a novel zeolite NaX-doped electrospun porous fiber membrane (Z-EPFM) was fabricated by using the electrospinning technique with the addition of polyvinylidene fluoride (PVDF), zeolite NaX and polyvinylpyrrolidone (PVP) as porogen. The strategy of using PVP as a pore-forming agent to obtain porous Z-EPMFs is more efficient to achieve ammonium adsorption than improving the hydrophilicity of the zeolite NaX-doped electrospun fiber membrane (Z-EFM) by simply adding PVP. As the molecular weight and content of PVP increase, the ammonium adsorption efficiency, hydrophilicity and membrane pore size of Z-EPFMs increase, while their mechanical strength decreases, which is due to the formation of pore structures . The most efficient Z-EPFM (zeolite NaX load density of 0.78 mg/cm 2 ) achieved 96.91% ± 0.50% ammonium adsorption efficiency and 95.48% ± 4.52% organic carbon enrichment efficiency, which were maintained steadily over five regeneration cycles. Therefore, the Z-EPFM offered a novel approach for simultaneous ammonium recovery and organic matter enrichment, which could be proposed as an efficient method to regulate energy flow and control nitrogen nutrient in municipal wastewater.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Wen Yang,Chong Liu,Yongzhao Hou,Xiangjun Dai,Cheng Zhong,Yongqiang Ma,Meixian Jiang
In this work, a novel carbon-enriched SiC by the polymer derived ceramic (PDC-SiC) route was manufactured. By varying the branched chain of the preceramic polymer, the structure and electromagnetic properties of the obtained PDC-SiC ceramics can be effectively altered through carbon enrichment. Specially, PDC-SiC ceramics obtained from branched polysilylacetylene (PSA) constitute a composite material that contains nano-sized SiC grains, carbon nanotubes (CNTs), and silicon carbide nanowires (SiC nw ). Such PDC-SiC ceramics possess a complex three-dimensional network of CNT S /SiC nw , leading to remarkable microwave absorption properties. Notably, the PDC-SiC ceramics processed from dimethyl-polysilylacetylene (D-PSA) achieved a minimum reflection loss (RL min ) of −55.0 dB at 14.4 GHz, and an effective absorption bandwidth (EAB) extends across 5.5 GHz, with a thickness of 2 mm.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
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2021
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IF 9.709
Zhenzhong Hu,Xian Li,Yiming Sun,Omar Donovan Dacres,Yuxian Wang,Hongyun Hu,Huan Liu,Guangqian Luo,Hong Yao
A novel treatment denoted as the “Thermal-dissolution based carbon enrichment (TDCE)” was proposed in our previous work to effectively deoxygenate and de-ash biomass under mild conditions. The main reactions during this process occurred in a highly-dispersed and inert medium, thus its mechanism was unclear. In this study, cellulose was chosen as the model compound to investigate the underlying reaction mechanisms of TDCE process. It was confirmed that three distinct stages were involved in this process, which were physical dissolution stage, intramolecular deoxygenation and rearrangement stage, and stabilization stage. The deoxygenation attributed to the intramolecular dehydration at around 300 °C and the formations of CO 2 and CO through subsequent aromatization in liquid phase at around 350 °C. Around 67% and 19% of oxygen were removed by these two pathways, respectively. About 80% of carbon remained in the solid products in all conditions. A two-step process was verified for the aromatic substance formation: furan structure formation at the beginning and the subsequent conversion to benzene ring. Especially, unlike large molecular bio-char formation in conventional pyrolysis, small molecular aromatics were formed in TDCE process. Undoubtedly, the highly-dispersed and inert medium contributed to these intramolecular reactions and suppressed the intermolecular reactions, although it wasn’t involved in the chemical reactions. Hence, the unique reaction mechanism of biomass in a highly-dispersed medium was specified, providing theoretical guidance to the practical application of TDCE method.
研究领域:
能源与燃料
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化学工程
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环境科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
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2021
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IF 4.527
Jianrong Song,Gaoming Mo,Xiang Wu,Liu He,Qing Huang,Zhengren Huang
A liquid carbon-rich SiAlCN precursor is facilely synthetized by hydrosilylation between liquid polyaluminocarbosilane (LPACS) and 1,3,5,7-tetravinyl- 1,3,5,7-tetramethylcyclotetrasilazane {[CH 3 (CH 2 CH 2 )SiNH] 4 } (TeVSZ). The structural evolution during the polymer-ceramic conversion process is investigated by various methods. The results show that the main cured mechanism is β -addition on hydrosilylation, although α -addition on hydrosilylation, polymerization of vinyl groups and dehydrocoupling reaction between N–H bonds also occur during the cured process. During the pyrolysis process, dehydrogenation and dehydrocarbonation condensation reactions, transamination reactions occur, leading to formation of a three-dimensional network inorganic structure at 400–800 °C, where part of Al–O bonds convert to Al–N bonds. Then the network inorganic structure undergoes demixing and separation into amorphous SiAlCN(O) phase, where the amorphous turbostratic free carbon phase also form at 800–1200 °C. With demixing and decomposition of the amorphous carbon-rich SiAlCN(O) phase, the crystalline β-SiC and graphitic carbon start to form at about 1400 °C, the crystalline sizes of them both enlarge with increasing temperature. However, the crystal growth of β-SiC is distinctly inhibited due to existence of the rich carbon phase, tiny amounts of Al 2 O 3 and AlN . In addition, a small amount of AlN can promote the formation of α-SiC at 1800 °C.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）