CHEMOSPHERE
·
2019
·
IF 5.108
Dongdong Ge,Haiping Yuan,Yanwen Shen,Wenrui Zhang,Nanwen Zhu
Waste activated sludge (WAS), containing biological pathogens, chemical elements and high moisture (>99%), was generated continually from municipal sewage treatment plants. Sludge dewatering could diminish the volume of WAS and control the diffusion of environmental pollution efficiently. In this study, tannic acid (TA), as a plant-derived phenolic compound, was investigated for improving WAS dewaterability at different temperatures. Apparently, the WAS dewaterability was enhanced by TA conditioning in the range of 25–55 °C, but further increase in temperature did not significantly affect the dewatering. With the TA addition of 0.15 mmol/gTS (total solid) at 55 °C, the WAS dewaterability was improved by 84.5% decrease in capillary suction time (CST), 96.5% decrease in specific resistance of filtration (SRF), and 19.9% decrease in water content (Wc) of dewatered sludge cake. TA facilitated removing supernatant viscosity and protein of sludge EPS (extracellular polymeric substances), specifically with 88.9% and 75.0% protein removal of slime EPS (S-EPS) and loosely bound EPS (LB-EPS). Thermodynamics modeling revealed that the improved dewaterability was dominantly attributed to the hydrophobic bonding between TA and EPS proteins, which was strengthened with the increase in temperature. However, when the conditioning temperature exceeded 55 °C, thermal effect took place and accelerated the release of biopolymers into EPS and hence, counteracted the beneficial effect of TA conditioning to further improve WAS dewatering. The results offered not only the dewatering effectiveness and mechanism of TA conditioning, but also a potential approach of applying plant waste to treat WAS for the high dewaterability.
研究领域:
环境科学
·
环境工程
·
微生物学
·
化学工程
·
污染控制
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Xiaodong Wang,Lili Ye,Xiaoyuan Zhang,Zhihe Zhang,Jiuzhong Yang,Long Zhao
Acetaldehyde, ethylene oxide , and vinyl alcohol are three C 2 H 4 O isomers that are ubiquitous in combustion over a wide temperature range. A comprehensive reaction kinetics study has been performed for reactions that occur on the same C 2 H 4 O potential energy surface , mainly including the unimolecular reactions of three C 2 H 4 O isomers and the recombination reaction of CH 3 with HCO. Temperature- and pressure-dependent rate coefficients were updated or newly predicted by performing quantum chemical calculations coupled with RRKM/master equation simulations. The dominance of C C bond fission is reconfirmed for acetaldehyde decomposition at higher temperatures. The negligible contribution of CH 4 + CO channel from usual tight intramolecular H-shift transition state provides indirect evidence for previously reported roaming mechanism that was proposed to explain the observation of CH 4 + CO in acetaldehyde pyrolysis . For ethylene oxide pyrolysis , current experiment and kinetic prediction have a good consistency in branching ratios between the formation of acetaldehyde and vinyl alcohol products. The radicals of CH 3 + HCO can also be directly generated from ethylene oxide through a well-skipping reaction mechanism especially at higher temperatures. For CH 3 + HCO recombination, we highlight the importance of CH 3 CO + H channel that was often overlooked previously. Kinetic simulations show that the incorporation of updated rate coefficients and newly identified channels results in a measurable influence on C2 chemistry , indicating the possibility and necessity of further improvement of core mechanism in combustion kinetic models .
研究领域:
物理化学
·
燃烧化学
·
反应动力学
·
量子化学计算
·
分子反应机制
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Zhuangzhi Wu,Min Ouyang,Dezhi Wang,Xinli Liu
The photoelectrocatalytic water splitting of molybdenum disulfide is hindered by the intrinsic large electrical resistance among adjacent layers, serious photo-generated carrier recombination and limited utilization of visible light . Herein, we construct MoS 2 /MoO 2 heterostructures via a facile in situ hydrothermal route, in which a Schottky junction is established between the MoS 2 semiconductor and metallic MoO 2 . As a result, the photoelectrochemical current density of MoS 2 /MoO 2 is enhanced about 1.6 times than that of pure MoS 2 , achieving −10.3 mA cm −2 at −1.8 V vs. SCE, which can be attributed to the reduced electron transfer resistance, enlarged photo-generated carrier separation efficiency and enhanced light absorption due to the presence of metallic MoO 2 .
研究领域:
材料科学
·
物理化学
·
能源化学
·
半导体催化
·
光电子学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2018
·
IF 3.741
Yue Han,Donghao Tang,Guangxing Wang,Ying Guo,Heng Zhou,Wenfeng Qiu,Tong Zhao
Low melting phthalonitrile monomers containing allyl and/or methoxyl groups were designed, synthesized and characterized. In order to evaluate their potential application in phthalonitrile resins, these monomers were blended with 1,3-bis(3,4-dicyanophenoxy)benzene and 4-(4-aminophenoxy)phthalonitrile, then cured into polymers. Curing mechanisms of different prepolymers were proposed and compared, and processability, thermal and mechanical properties were characterized. The introduction of methoxyl units was found to postpone the curing, and thermal properties were slightly compromised. On the contrary, the usage of allyl was beneficial to both processability and thermal properties. More importantly, the impact strength for allyl-containing polymers could be as high as 13.63 kJ m −2 , indicating such resin could be applied as high temperature structural composite matrices.
研究领域:
高分子化学
·
材料科学
·
复合材料
·
热固性树脂
·
高性能聚合物
✓ 已验证
DOI
高影响因子
SCRIPTA MATERIALIA
·
2020
·
IF 5.079
Feng Guo,Pengfei Wen,Bo Duan,Yao Li,Xilong Zhou,Pengcheng Zhai
Co 4 Sb 11.5 Te 0.5 hybrid composites with dual-nano inclusions (1 vol %) of SiC whiskers (SiC w ) and SiC particles (SiC p ) are prepared by spark plasma sintering . It is found that the hybrid composites exhibit further improved flexural strength and fracture toughness compared with those reinforced by SiC w or SiC p alone, indicating a striking synergistic enhancement effect. And the dimensionless figure of merit values of the hybrid composites remain nearly unchanged compared with the sample reinforced by individual inclusion. Our study provides an effective route to further improve the mechanical prosperities of thermoelectric materials .
研究领域:
材料科学
·
热电材料
·
复合材料
·
固态物理
·
无机非金属材料
✓ 已验证
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2019
·Vol. 304
·期 4
·1800689
·
IF 3.038
Jie Mei,Weifeng Liu,Jinhao Huang,Xueqing Qiu
It is still a great challenge to prepare lignin/polyolefin composites with good strength and toughness. Inspired by the energy sacrificial mechanism from biomaterials, dynamic hydrogen bonds (H-bonds) are incorporated into the lignin/ethylene-propylene-diene monomer (EPDM) composite system to improve the interfacial interactions between lignin and EPDM. Such H-bonding interactions are demonstrated to be able to simultaneously improve the modulus, strength, and toughness of lignin/EPDM composites without sacrificing the extensibility. This work provides a facile method for the high-valued utilization of lignin in the preparation of high-performance elastomer composites using bio-renewable resources as reinforcing agent.
研究领域:
高分子材料
·
复合材料科学
·
生物基聚合物
·
功能材料
·
可持续材料
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 45
·51348
·
IF 3.125
Junming Chen,Jinxuan He,Longquan Liu,Yongzhu He,Xiaobin Huang
Polymeric ablative materials (PAMs) are widely used in spacecraft currently for thermal insulation. However, it is challenging to find a single filler that can improve both ablative and mechanical properties of PAMs. In this study, a new type of hybrid cross-linked polyphosphazene microspheres (PHC) is added to ethylene propylene diene monomer (EPDM) composites as a filler for the first time and its influence on the ablation, mechanical, and thermal properties of EPDM is investigated. The results show that the addition of 3 phr PHC increases the ablation performance by about 10% and enhances the mechanical properties by 20% approximately. In addition, the ablation mechanism is studied in accordance with SEM, FTIR, and Raman spectroscopy. On the one hand, PHC has the effect of catalyzing carbonization, thus increasing the rate of residual carbon; on the other hand, PHC changes the morphology of the char layer, forming a cross-linked structure containing P─O─Si bonds on the surface. The findings regarding catalyzing carbonization and the special char layer structure could guide the design of ablative materials.
研究领域:
高分子材料
·
航天热防护
·
复合材料科学
·
材料化学
·
热力学
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2015
·Vol. 2015
·期 1
·371404
·
IF 1.644
Wei-Wen Li,Wei-Ming Ji,Yi Liu,Feng Xing,Yu-Kai Liu
This study aimed to explore the damping property of a cement-based material with carbon nanotube (CNT). In the study, the cement composites with different contents of CNT (0 wt%, 0.033 wt%, 0.066 wt%, and 0.1 wt%) were investigated. Logarithmic Decrement method and Dynamic Mechanical Analysis (DMA) method were utilized to study the damping property of CNT/cement composite. The influences of CNT on pore size distribution and microstructure of composite were analyzed by Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscopy (SEM), respectively. The experimental results showed that CNT/cement composite presented higher flexural strength index than that of a pure cement paste. Additional CNT could improve the vibration-reduction capacity of cement paste. Furthermore, the experiments proved that CNT could bridge adjacent hydration products and support load transfer within cement matrix, which contributed to the energy dissipation during the loading process.
研究领域:
材料科学
·
建筑材料
·
复合材料
·
土木工程材料
·
功能材料
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2016
·Vol. 122
·期 7
·678
·
IF 1.444
Yin Xin,Song Lixin,Xie Xueyao,Zhou Yangyang,Guan Yingli,Xiong Jie
The flexible ZrO 2 /C composite nanofibrous film was fabricated by electrospinning and thermal treatment. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffractometer, and Fourier transform infrared spectra were used to characterize the morphology and microstructure of the ZrO 2 /C composite nanofibrous film. The ZrO 2 /C nanofibers exhibited rough surface and had the average diameter of about 230 ± 35 nm. And the ZrO 2 nanoparticles were incorporated in carbon matrix and in tetragonal and monoclinic. The flexural property of the ZrO 2 /C composite nanofibrous film was investigated in detail. The results showed that the flexural property of the nanofibrous film was greatly improved with addition of the ZrO 2 nanoparticles. Besides, with the increase of the contents of ZrO 2 nanoparticles, the flexural modulus of the nanofibrous film decreased, reached a lowest value, and then increased. The lowest flexural modulus of the ZrO 2 /C composite nanofibrous film in precursor concentration of 7.0 wt% was 8.55 ± 0.06 MPa.
研究领域:
材料科学
·
纳米科技
·
复合材料
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Ruiyong Wang,Xiaohui Kang,Ruiqiang Wang,Rui Wang,Huanjing Dou,Jing Wu,Chuanjun Song,Junbiao Chang
The interactions between trypsin and caffeine/theophylline were investigated by fluorescence spectroscopy , UV–visible absorption spectroscopy , resonance light scattering and synchronous fluorescence spectroscopy under mimic physiological conditions . The results revealed that the fluorescence quenching of trypsin by caffeine and theophylline was the result of the formed complex of caffeine–trypsin and theophylline–trypsin. The binding constants and thermodynamic parameters at three different temperatures were obtained. The hydrophobic interaction was the predominant intermolecular forces to stabilize the complex. Results showed that caffeine was the stronger quencher and bound to trypsin with higher affinity than theophylline .
研究领域:
生物化学
·
分子药理学
·
药物代谢
·
蛋白质-配体相互作用
·
光谱学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Peng Yi-Zhu,Ma Wan-Hong,Jia Man-Ke,Zhao Xiao-Rong,David M. Johnson,Huang Ying-Ping
In this study, a weakly polar pesticide acetochlor in water was tried to degrade by BiOBr catalysts under visible light irradiation. Its degradation reaction rate increased exponentially with increasing catalyst dosage, which was significantly different from conventional photocatalytic patterns established for polar or water-soluble pollutants. Thus, the rate-dosage relationship of BiOBr/acetochlor was compared to that of BiOBr/Rhodamine B (RhB) (a typical strong polar dye pollutant in water) at different BiOBr dosages. The degradation rate of RhB increased with the BiOBr dosage and then plateaued due to more catalyst particles blocking the light into the inner solution, which is a typical behavior for heterogeneous photocatalysis of polar organic compounds in aqueous solution. While acetochlor behaved differently, its degradation rate increased exponentially with the BiOBr dosage, and no plateau was observed even up to 9.0 g/L BiOBr dosage. This special rate-dose relationship for weakly polar acetochlor was correlated with a unique adsorption property of BiOBr to acetochlor in water solution. There was a re-distribution effect that always exclude excessive acetochlor adsorbed on BiOBr surface regardless either substrates or BiOBr overdose. This finally resulted in every BiOBr particle having enough adsorption sites available for dissolved dioxygen to function thereby accelerate the degradation of weakly polar organic compounds in water.
研究领域:
环境化学
·
光催化
·
水污染控制
·
环境功能材料
·
污染物降解机制
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2017
·Vol. 25
·期 10
·1435-1441
·
IF 1.174
Zhirong Chen,Weitao Yang,Hong Yin,Shenfeng Yuan
The uncatalyzed reaction of p -tolyl isocyanate ( p -TI) with water in N , N -dimethylformamide (DMF) was investigated by high performance liquid chromatography (HPLC). The reactions were carried out at different temperatures from 293 K to 323 K, using various molar ratios of water to p -TI. DMF, as a special amide , was proved to be an efficient catalyst for water–isocyanate reaction. Under the reaction conditions in this study, substituted urea was the only final product observed. An appreciable amount of intermediate p -toluidine was detected. Concentrations of the isocyanate group as well as the amine and urea were determined as a function of time. New kinetic equations were deduced for each of the substance on the basis of a multistep mechanism, instead of a simple second order reaction as usual. Kinetic constants were calculated using the software MATLAB . Furthermore, the effects of temperature and concentrations of reactants on the reaction rate and amine content were discussed. The activation energy of each step was also determined.
研究领域:
物理化学
·
有机化学
·
反应动力学
·
高分子化学
·
催化化学
·
分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）