PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2018
·Vol. 37
·期 1
·565-573
·
IF 5.336
Xiaoyuan Zhang,Yuyang Li,Chuangchuang Cao,Jiabiao Zou,Yan Zhang,Wei Li,Tianyu Li,Jiuzhong Yang,Philippe Dagaut
The kinetics of propanal oxidation was studied in a jet-stirred reactor (JSR) at atmospheric pressure. The investigated temperature range is from 450 to 800 K at two different equivalence ratios (0.35 and 4.0). Thanks to the synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS), critical intermediates were identified, including methylperoxy, methyl hydroperoxide , ethylperoxy, ethyl hydroperoxide, α-lactone, β-propiolactone and ketohydroperoxides. A kinetic model for propanal oxidation was also developed and validated against the present experimental results, as well as those available from the literature. Main chain-branching pathways under the investigated conditions were analyzed based on present experimental data and kinetic model . The O 2 addition reaction to the propanoyl radical and subsequent oxidation reactions play an important role in determining the oxidation rate of propanal under fuel-lean conditions, especially in the low-temperature oxidation region. Under fuel-rich conditions, the decomposition of the propanoyl radical is predominant and C 2 H 5 relevant reactions consequently determine the kinetics of oxidation of propanal.
研究领域:
物理化学
·
燃烧化学
·
反应动力学
·
分析化学
·
能源化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 28
·14162-14170
·
IF 11.301
Zhihong Du,Keyun Li,Hailei Zhao,Xu Dong,Yang Zhang,Konrad Świerczek
Modified by Sm0.2Ce0.8O2−δ (SDC) nanoparticles (NPs), SmBaCo2O5+δ (SBCO) double perovskite oxide is evaluated as a promising cathode material for intermediate temperature solid oxide fuel cells. The SDC NPs are epitaxially grown on the surface of SBCO with (220) planes of SDC aligning smoothly to (020) or (100) planes of SBCO, forming a tight, coherent connection at the interface. The influence of this modification on thermal expansion, oxygen diffusion, electrical conductivity and electrochemical properties is investigated thoroughly in this work. The designed SBCO–SDC cathode material demonstrates a lower thermal expansion coefficient (TEC), ∼16.4 × 10−6 K−1, than that of the unmodified SBCO, ∼20.9 × 10−6 K−1. While SDC coating results in a decreased total electrical conductivity, it facilitates oxygen bulk diffusion and improves the surface exchange reaction kinetics. Coating with SDC NPs can accelerate the rate-determining process of dissociation of the absorbed molecular oxygen, especially at intermediate temperatures. Accordingly, the constructed symmetrical cell with the La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM) electrolyte shows lower polarization resistance values, if the SBCO–SDC cathode is utilized. Also, the LSGM electrolyte-supported (300 μm) full cell is found to deliver a high power density of 800 mW cm−2 at 800 °C. Owing to the strong and coherent interfacial connection, the developed cathode demonstrates a relatively steady electrochemical performance.
研究领域:
材料科学
·
能源化学
·
电化学
·
无机功能材料
·
燃料电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2014
·Vol. 119
·期 1
·205-212
·
IF 2.206
Yang Ting,Chen Liping,Chen Wanghua,Zhou Yishan,Gao Haisu,Zhong Tingting
2-Ethylhexyl nitrate (EHN) is an important material, which is produced by concentrated HNO 3 –H 2 SO 4 nitration process. But EHN is not a stable material, especially mixed with acids. To analyze the stability of EHN with concentrated acid under serious condition, four samples (pure EHN, concentrated sulfuric acid with EHN, concentrated nitric acid with EHN, and mixed acid with EHN) and three acids (sulfuric acid, nitric acid, and mixed acid) were measured by differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC) in this paper. The results indicated that concentrated sulfuric acid, concentrated nitric acid, and mixed acid all could decrease the onset decomposition temperature of EHN, especially concentrated sulfuric acid. DSC results also showed that the heat of EHN decomposition with nitric acid is larger than other samples. Based on ARC data, the kinetic parameters and T
D24 (temperature at which TMR
ad is 24 h) were calculated. The activation energy and T
D24 of the EHN with acids, especially with concentrate sulfuric acid, were much lower than the pure EHN. It can be concluded that acids could decrease the stability of EHN and that is an important reason for frequent accidents.
研究领域:
物理化学
·
安全工程
·
材料化学
·
热分析
·
危险品管理
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Chao Liu,Yufei Dong,Yang Lin,Hongxia Yan,Wenbo Zhang,Yan Bao,Jianzhong Ma
In order to simultaneously improve the dispersibility of graphene in the bismaleimide (BMI) resin and the interfacial interaction between them, the polytriazine@RGO nanocomposite (PTZ@RGO) with terminal amine was obtained by the method of one-step precipitation polymerization. The PTZ@RGO hybrid nanocomposite was then chosen as filler to improve the mechanical and tribological properties of BMI resin. Through effective surface modification, the compatibility and interface strength between graphene and BMI matrix were significantly improved, leading to the flexural strength , impact strength , anti-friction, wear resistance and thermal stability of PTZ@RGO/BMI composites were significantly improved as compared to those of neat BMI resin and RGO/BMI composites. The other properties including hardness and thermal properties of composites were all improved with increasing amount of PTZ@RGO fillers. These high performance BMI composites have a great potential for application in aerospace, mechanical engineering and other automobile brake devices.
研究领域:
材料科学
·
高分子复合材料
·
表面工程
·
摩擦学
·
航空航天材料
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2021
·
IF 4.185
Jizhen Zhu,Sixu Wang,Mohsin Raza,Yuan Feng,Jing Li,Yebing Mao,Liang Yu,Yong Qian,Xingcai Lu
Methanol is an attractive oxygenate increasingly used as primary fuel for dual-fuel combustion technology yielding beneficial thermal-efficiency and emissions in modern engines. As such, it is significant to fundamentally understand the autoignition behavior of methanol/diesel mixtures. This study measured the ignition delay times (IDTs) of methanol/diesel blends with different mixing ratios (30%, 50%, 70% methanol by mol.) on a heated shock tube and a heated rapid compression machine at temperatures of 650−1450 K, pressures of 6−20 bar, and equivalence ratios of 0.5, 1.0 and 2.0. The typical two-stage ignition characteristics with the negative temperature coefficient response were observed for dual-fuel mixtures. In general, both the total and first-stage IDTs decrease with the increment of pressure and equivalence ratio as well as diesel proportion in mixtures. The simulation results performed with a published detailed mechanism in conjunction with a tri-component diesel surrogate demonstrate generally good agreement with the experimental data at all test conditions. Moreover, a crossover of IDTs occurs at a higher temperature (~1500 K) for varying equivalence ratios, and experiment and simulation both exhibit a non-linear mixing effect of methanol addition on diesel ignition. Interestingly, simulation results clearly suggest a crossover (~940 K) for mixtures with varying methanol content at an intermediate-temperature, where the IDT of the mixture with a lower methanol ratio becomes longer as the temperature is higher than that of the crossover. Furthermore, brute-force sensitivity analyses assisted with reaction path analysis were conducted to gain deeper insights into the autoignition chemistry of dual-fuel mixtures, especially for the chemical interaction between both fuels during the low-temperature oxidation process . It is found that methanol hardly generates •OH, whereas •OH is mainly produced by the low-temperature reaction pathways of diesel. Thus, •OH is the bridge for both fuels during the ignition process. At the high methanol ratio, the H-abstraction of diesel is mainly via •HO 2 while CH 3 OH consumes a large percentage of •OH. Consequently, the competition between methanol and diesel for •OH radicals inhibits the overall reactivity of reaction network. In addition, the original data reported here lay a foundation for the development and validation of more accurate and robust dual-fuel kinetic schemes.
研究领域:
燃烧化学
·
燃料科学
·
化学动力学
·
内燃机工程
·
替代燃料技术
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 131
·期 9
·
IF 1.395
Chang Su,Dezhen Zong,Lihuan Xu,Cheng Zhang
In this article, semi-interpenetrating polymer network (Semi-IPNs) based on nitrile rubber (NBR) and poly(methyl methacrylate- co -butyl acrylate) (P(MMA-BA)) were synthesized. The structure and damping properties of the prepared Semi-IPNs blends were characterized and by fourier transform infrared spectrum (FTIR), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), thermogravimetric analysis (TGA/DTG), and tensile mechanical properties. The results showed that interpenetrating network based on P(MMA-BA) and NBR was successfully obtained, which showed the improved thermal stability compared to NBR/P(MMA-BA)-based two-roll mill blends. Furthermore, Semi-IPNs showed significantly better the dynamic mechanical properties than that of the two-roll mill system. With the increasing feed ratio of BA and MMA during the preparation of Semi-IPNs, the loss peak position for P(MMA-BA) in NBR/PMMA IPNs shifted to a lower temperature from 20°C to −17°C, and when NBR in Semi-IPNs was accounted for 40 wt %, the dynamic mechanical thermal analysis showed that much more advanced damping material with wider temperature range (−30°C < T < 80°C) as tan δ > 0.45 can be achieved. Therefore, it was expected as a promising way to obtain the excellent damping materials with good oil-resisted properties according the Semi-IPNs system. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40217.
研究领域:
高分子材料科学
·
功能材料
·
复合材料
·
材料物理
·
阻尼材料
·
聚合物改性
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2016
·Vol. 7
·期 8
·1602149
·
IF 15.23
Shanshan Yao,Jiang Cui,Ziheng Lu,Zheng-Long Xu,Lei Qin,Jiaqiang Huang,Zoya Sadighi,Francesco Ciucci,Jang-Kyo Kim
Carbon-coated van der Waals stacked Sb 2 S 3 nanorods (SSNR/C) are synthesized by facile hydrothermal growth as anodes for sodium ion batteries (SIBs). The sodiation kinetics and phase evolution behavior of the SSNR/C anode during the first and subsequent cycles are unraveled by coupling in situ transmission electron microscopy analysis with first-principles calculations. During the first sodiation process, Na + ions intercalate into the Sb 2 S 3 crystals with an ultrafast speed of 146 nm s −1 . The resulting amorphous Na x Sb 2 S 3 intermediate phases undergo sequential conversion and alloying reactions to form crystalline Na 2 S, Na 3 Sb, and minor metallic Sb. Upon desodiation, Na + ions extract from the nanocrystalline phases to leave behind the fully desodiated Sb 2 S 3 in an amorphous state. Such unique phase evolution behavior gives rise to superb electrochemical performance and leads to an unexpectedly small volume expansion of ≈54%. The first-principles calculations reveal distinctive phase evolution arising from the synergy between the extremely low Na + ion diffusion barrier of 190 meV and the sharply increased electronic conductivity upon the formation of amorphous Na x Sb 2 S 3 intermediate phases. These findings highlight an anomalous Na + ion storage mechanism and shed new light on the development of high performance SIB anodes based on van der Waals crystals.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
固态物理
·
计算材料学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Xuliang Lin,Xueqing Qiu,Duming Zhu,Zihao Li,Ningxin Zhan,Jieyi Zheng,Hongming Lou,Mingsong Zhou,Dongjie Yang
Effect of the molecular structure of lignin-based polyoxyethylene ether (EHL–PEG) on enzymatic hydrolysis of Avicel and corn stover was investigated. With the increase of PEG contents and molecular weight of EHL–PEG, glucose yield of corn stover increased. EHL–PEG enhanced enzymatic hydrolysis of corn stover significantly at buffer pH 4.8–5.5. Glucose yield of corn stover at 20% solid content increased from 32.8% to 63.8% by adding EHL–PEG, while that with PEG4600 was 54.2%. Effect of EHL–PEG on enzymatic hydrolysis kinetics of cellulose film was studied by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). An enhancing mechanism of EHL–PEG on enzymatic hydrolysis kinetics of cellulose was proposed. Cellulase aggregates dispersed by EHL–PEG excavated extensive cavities into the surface of cellulose film, making the film become more loose and exposed. After the maximum enzymatic hydrolysis rate, the film was mainly peeled off layer by layer until equilibrium.
研究领域:
生物质转化
·
酶工程
·
高分子化学
·
表面科学
·
可再生能源
✓ 已验证
DOI
高影响因子
Acta Biomaterialia
·
2021
·
IF 8.947
Xian Tong,Wenhao Cai,Jixing Lin,Kun Wang,Lufan Jin,Zimu Shi,Dechuang Zhang,Jianguo Lin,Yuncang Li,Matthew Dargusch,Cuie Wen
Zinc (Zn)-based alloys have been considered potential biodegradable materials for medical applications due to their good biodegradability and biocompatibility. However, the insufficient mechanical properties of pure Zn do not meet the requirements of biodegradable implants. In this study, we have developed a biodegradable Zn−3Mg−0.7Mg 2 Si composite fabricated by high-pressure solidification. Microstructural characterization revealed that the high-pressure solidified (HPS) composite exhibited uniformly distributed fine MgZn 2 granules in an α-Zn matrix. Comprehensive tests indicated that the HPS composite exhibited exceptionally high compression properties including a compressive yield strength of 406.2 MPa, an ultimate compressive strength of 1181.2 MPa, and plastic deformation up to 60% strain without cracking or fracturing. Potentiodynamic polarization tests revealed that the HPS composite showed a corrosion potential of −0.930 V, a corrosion current density of 3.5 μA/cm 2 , and a corrosion rate of 46.2 μm/y. Immersion tests revealed that the degradation rate of the HPS composite after immersion in Hanks’ solution for 1 month and 3 months was 42.8 μm/y and 37.8 μm/y, respectively. Furthermore, an extract of the HPS composite exhibited good cytocompatibility compared with as-cast (AC) pure Zn and an AC composite at a concentration of ≤25%. These results suggest that the HPS Zn−3Mg−0.7Mg 2 Si composite can be anticipated as a promising biodegradable material for orthopedic applications .
研究领域:
生物医学工程
·
材料科学
·
生物材料
·
骨科
·
可降解金属
·
组织工程
·
腐蚀科学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2013
·
IF 3.535
Kelei Zhuo,Yujing Wei,Jingjing Ma,Yujuan Chen,Guangyue Bai
Several alkylmethylimidazolium tetraphenylborates (C n mim-TPB, n = 2–10) were synthesized and explored as ion exchangers in plasticized PVC membranes with very attractive sensing behaviors. And then a series of ion-selective electrodes (ISEs) were prepared and their potentiometric properties were investigated. The proposed electrodes exhibited Nernstian responses to alkylmethylimidazolium-based ionic liquid cations [C n mim] + . These electrodes were successfully applied in the determination of thermodynamic parameters of ionic liquids in aqueous solutions and in the detection of [C n mim] + in tap water and distilled water with satisfactory results. For the as-prepared ISEs, one special and important relationship was observed between the selectivity coefficients and the length of alkyl side chains of interfering cations [C n mim] + . The proper understanding of this relationship should facilitate the development of new method for the determination of ionic liquids using ISEs.
研究领域:
分析化学
·
电化学
·
环境监测
·
离子传感
·
药物分析
·
水处理
·
生物传感器
·
物理化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Kai Wang,Guangzhen Li,Yanhong Li,Yuan Chen,Ling Zhang,Zhiying Zhu,Zhiyong Xu,Wenbo Zhao
In the present work, a kind of amine alkyl siloxane N -butyl-N-((1,1,3-trimethyl-3,3-diphenyldisiloxaneyl)methyl)butan-1-amine (BTDMBA) was synthesized and used to capture SO 2 . Its thermal decomposition temperature is 160℃, which is comparable with that of Ionic liquids (ILs), but its viscosity is only 125 mPa∙s at 25℃ after the absorption of SO 2 , which is much lower than that of ILs. The reaction mechanism is that BTDMBA reacted with SO 2 to form charge transfer complex BTDMBA∙SO 2 . The reaction enthalpy and entropy change are −83.95 kJ/mol and −240.48 J·mol −1 ·K −1 , respectively, which are more negative than that of ILs. By comparing the enthalpy and entropy change of amine alkyl siloxane and absorbents reported in literatures, an unexpected entropy enthalpy compensation phenomenon was discovered and the isokinetic temperature was found to be 371 K. Based on this phenomenon and the optimization objective function, it was also found that with the decrease of entropy change, the optimal absorption and desorption temperature difference increased initially and decreased afterwards. The maximum of entropy changes is −201 J·mol −1 ·K −1 for absorbent to achieve recycle absorption capacity 0.79 mol/mol under the condition of absorption pressure 0.002 bar and desorption pressure 1 bar.
研究领域:
物理化学
·
环境化学
·
分离科学
·
能源材料
·
工业气体净化
·
绿色化工
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2017
·
IF 3.101
Long Mao,Yuejun Liu,Huiqing Wu,Jianhong Chen,Jin Yao
Inspired by the versatile adhesion capability of marine adhesive proteins, core-shell structured polydopamine-coated layered double hydroxide (LDH@PDA) were prepared successfully by in-situ growing PDA on the surface of MgAl-LDH with a high aspect ratio . LDH@PDA/poly(ε-caprolactone) (PCL) nanocomposites were prepared by blending LDH@PDA and pure PCL via solution casting method to obtain homogeneous films. The results of thermal analysis confirmed that LDH@PDA can act as a nucleating agent . And thermal stability of nanocomposites was improved due to core-shell structured LDH@PDA. With incorporation of as low as 1 wt% of LDH@PDA, a 20% increase in tensile strength (41.1 MPa), 26% increase in elongation at break (772%) and 26% reduction in the oxygen relative permeability were achieved. The improvement in the mechanical and gas barrier properties of nanocomposites at low filler loading was attributed to the strong interfacial interaction of LDH@PDA wtih the PCL matrix.
研究领域:
高分子材料
·
纳米复合材料
·
生物医用材料
·
材料科学
·
表面改性
·
气体阻隔
·
力学性能
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）