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Toughening of vinyl ester resins by two-dimensional MXene nanosheets

《化学科学与工程前沿（英文）》   页码 1651-1658 doi: 10.1007/s11705-022-2208-5

摘要： Two-dimensional nanosheets are highly effective tougheners for vinyl ester resins. The toughening effect is related to the high specific surface area and unique two-dimensional planar structure of the nanosheets. In this study, a coupling agent γ-(2,3-epoxypropoxy) propytrimethoxysilane (Kh-560) was used to modify MXene nanosheets (M-MXene) for use in toughening vinyl ester resin. The mechanical properties, including the tensile strength, flexural strength, Young’s modulus and elongation, of neat vinyl ester resin and vinyl ester resin modified with MXene and M-MXene were investigated. The results showed that modification significantly improved the mechanical properties of the vinyl ester resin. The tensile and flexural strengths of the MXene-nanosheet-modified vinyl ester resin were 27.20% and 25.32% higher, respectively, than those of the neat vinyl ester resin. The coupling agent improved the interfacial compatibility between the MXene nanosheets and vinyl ester resin, which resulted in the tensile and flexural strengths of the M-MXene-nanosheet-modified vinyl ester resin being 52.57% and 54.60% higher, respectively, than those of the neat vinyl ester resin for a loading quantity of nanosheets of only 0.04 wt %, which is economically viable. The main mechanisms by which the nanosheets toughen the resin are crack deflection and crack pinning.

关键词： MXene nanosheets     2D material     vinyl ester resin     modification     coupling agent    

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The prediction of adsorption isotherms of ester vapors on hypercrosslinked polymeric adsorbent

Liuyan WU,Lijuan JIA,Xiaohan LIU,Chao LONG

《环境科学与工程前沿（英文）》 2016年 第10卷 第3期   页码 482-490 doi: 10.1007/s11783-015-0826-6

摘要： Adsorption isotherms of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate and ethyl propionate on hypercrosslinked polymeric resin (ND-100) were measured at 303K, 318K and 333K,respectively, and well fitted by Dubinin–Astakhov (DA) equation. The plots of the adsorbed volume ( ) versus the adsorption potential ( ) at three different temperatures all fell basically onto one single curve for every ester. A predicted model based on DA equation was obtained on the basis of adsorption equilibrium data of methyl acetate, ethyl acetate and ethyl propionate at 318K. The model equation successfully predicted the adsorption isotherms of methyl acetate, ethyl acetate and ethyl propionate on ND-100 at 303K, and 333K, and also gave accurate predictive results for adsorption isotherms of the other two ester compounds (propyl acetate and isopropyl acetate) on ND-100 at 303K, 318K and 333K. The results proved the effectiveness of DA model for predicting the adsorption isotherms of ester compounds onto ND-100. In addition, the relationship between physico-chemical properties of adsorbates and their adsorption properties was also investigated. The results showed that molecular weight, molar volume and molar polarizability had good linear correlations with the parameter (which represents adsorption characteristic energy) of DA equation.

关键词： hypercrosslinked polymeric adsorbent     adsorption isotherm     ester     prediction    

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Reaction and characterization of crosslinking hyperbranched poly (amine-ester) with succine anhydride

XIAO Ling, WEI Xiuzhen, ZHU Baoku

《化学科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 355-359 doi: 10.1007/s11705-007-0064-y

摘要： Basing on hydroxyl terminated hyperbranched poly (amine-ester)s (HPAEs), the cross-linking reactions and preparation of ester-crosslinked HPAE films were investigated using succine anhydride (SA) as crosslink reagent. It was proved that the cross-linking reaction between HPAE and SA followed a two-step mechanism. This mechanism provides an efficient route to prepare HPAE/SA cross-linked films, in which, the precursor films were prepared by casting HPAE/SA solution at a lower temperature, and then curing the films at a higher temperature. By varying SA content, the solid HPAE/SA films with different cross-linking degrees were prepared successfully. The highest tensile strength of the cross-linked film could reach 59.60 MPa. With all water contact angle smaller than 74.3°, the crosslinked films demonstrated good hydrophilic properties.

关键词： different cross-linking     amine-ester     temperature     crosslinked     efficient    

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用于锂离子电池的富醚/酯/氟黏结剂配方 Article

Xianqing Zeng, Donglin Han, Zeheng Li, Hongxun Wang, Gu Wu, Yong Deng, Kai Liu, Li Xie, Chengdu Liang, Min Ling, Yuchuan Huang

《工程（英文）》 2022年 第19卷 第12期   页码 199-206 doi: 10.1016/j.eng.2022.05.020

摘要：

由于硅阳极体积膨胀过大，无法在高能量密度电池中实现实际应用。研究人员一直专注于在阳极中添加黏结剂以限制体积膨胀，来解决这一问题，因为黏结剂的氢键和机械性能可以用来增强黏附力和适应硅阳极的体积变化。在这里，我们综合考虑了黏结剂的氢键、力学性能、稳定性以及与电解液的相容性，设计了一种富醚/酯/氟的复合聚合物P(TFEMA-co-IBVE)。该黏结剂配方具有优异的稳定性、黏结性和机械强度，能够适应硅电极体积的剧烈变化，表现出优异的电化学性能，面积容量高达5.4 mA∙h∙cm−2。这种新型聚合物设计可应用于下一代锂离子电池的其他电极材料。

关键词： 硅阳极     乳液共聚合     氟原子     醚     酯    

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Potential hybrid feedstock for biodiesel production in the tropics

Solomon GIWA,Oludaisi ADEKOMAYA,Collins NWAOKOCHA

《能源前沿（英文）》 2016年 第10卷 第3期   页码 329-336 doi: 10.1007/s11708-016-0408-8

摘要： Recently, mixture of different oils at various proportions have been used as feedstock for biodiesel production. The primary aim is to improve fuel properties which are strongly influenced by the fatty acid composition of the individual oil that makes up the feedstock mix. The tropics are renowned for abundant oil-bearing crops of which palm kernel oil (PKO) from palm seed and groundnut oil (GNO) are prominent. This present paper investigated biodiesel production from hybrid oil (HO) of PKO (medium carbon chain and highly saturated oil) and GNO (long carbon chain and highly unsaturated oil) at 50/50 (v/v) blending. The principal fatty acids (FAs) in the HO are oleic (35.62%) and lauric acids (24.23%) with 47.80% of saturated FA and 52.26% of unsaturated FA contents. The chemical conversion of the oil to methyl ester (ME) gave 86.56% yield. Fuel properties of hybrid oil methyl ester (the HOME) were determined in accordance with standard test methods and were found to comply with both ASTM D6751 and EN 14214 standards. The oxidative stability, cetane number and kinematic viscosity (KV) of HOME were observed to be improved when compared with those of GNO methyl ester from single parent oil, which could be accredited to the improved FA composition of the HO. The KV (3.69 mm /s) of HOME obtained in this paper was remarkably low compared with those reported in literature for most biodiesels. This value suggests better flow, atomization, spray and combustion of this fuel. Conclusively, the binary blend of oils can be a viable option to improve the fuel properties of biodiesel feedstock coupled with reduced cost.

关键词： groundnut oil     palm kernel oil     methyl ester     fuel properties     tropics     fatty acid composition    

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Supercritical carbon dioxide extraction of CLA-ethyl ester

Yingdi CHEN, Peng XU, Jian CHENG

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 102-106 doi: 10.1007/s11705-010-0536-3

摘要： Supercritical carbon dioxide (SC-CO ) extraction of Conjugated linoleic acid (CLA) ethyl ester was investigated at pressures in the range of 9 to 10.5 MPa and temperature gradients ranging from 0°C to 21°C. The content of CLA-ethyl ester in the fraction was analyzed with gas chromatography (GC). The experimental results indicated that the rate of extraction would rise with the increase of pressure when temperature gradient was given. Moreover, the extraction pressure had insignificant influence on the selectivity of CLA-ethyl ester in SC-CO . When pressure was fixed, setting certain temperature gradient can improve the selectivity of CLA-ethyl ester in SC-CO , and CLA-ethyl ester can be concentrated more effectively than without a temperature gradient. The acid value and peroxide value of the fractions were reduced obviously, compared to the raw material. The optimal condition is pressure at 10 MPa and temperature gradient at 11°C.

关键词： supercritical carbon dioxide     extraction     CLA-ethyl ester     temperature gradient    

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Ternary phase behavior of water microemulsified diesel-palm biodiesel

Nurul Atiqah Izzati MD ISHAK,Ismail Ab RAMAN,Mohd Ambar YARMO,Wan Mohd Faizal WAN MAHMOOD

《能源前沿（英文）》 2015年 第9卷 第2期   页码 162-169 doi: 10.1007/s11708-015-0355-9

摘要： This paper aims to develop a new microemulsions system comprising diesel and palm oil methyl ester (PME) that have the potential to be used as alternative fuels for diesel engines. The water-in-diesel-biodiesel microemulsions were prepared by applying PME mixed with diesel, non-ionic surfactants, co-surfactants and water to make the water-in-oil (W/O) microemulsion system. This microemulsified fuel was achieved through low-energy microemulsification by using the constant composition method. The diesel used was mixed with four different concentrations of PME, i.e., 10% (w/w) (B10), 20% (w/w) (B20), 30% (w/w) (B30) and neat diesel (B0). The amount of water was fixed at 20% (w/w). The phase behavior of the water/mixed non-ionic surfactant/diesel-PME system were studied by constructing pseudoternary phase diagrams with the goal of formulating optimized systems. The results showed that the microemulsions were formed and stabilized with a mixture of non-ionic surfactants at a weight ratio of 80:20 at 20% (w/w), and with mixed co-surfactants at a weight ratio of 25:75, 20:80 and 10:90 for B0, B10, B20 and B30 respectively. The particle size, kinematic viscosity at 40°C, refractive index, density, heating value, cloud point, pour point and flash point of the selected water-in-diesel microemulsion were 19.40 nm (polydispersity of 0.12), 2.86 mm /s, 1.435, 0.8913 g/mL, 31.87 MJ/kg, 7.15°C, 10.5°C and 46.5°C respectively. The corresponding values of the water-in-diesel-PME selected were 20.72 nm to 23.74 nm, 13.02 mm /s to 13.29 mm /s, 1.442, 0.8939 g/mL to 0.8990 g/mL, 31.45 MJ/kg to 27.34 MJ/kg, 7.2°C to 6.8°C, 8.5°C to 1.5°C and 47.5°C to 52.0°C. These preliminary findings were further studied as potential fuels for diesel engines.

关键词： palm methyl ester     palm oil biodiesel     microemulsion     water microemulsified fuels    

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Role of nitric oxide in biological effects of vascular endothelial growth factor

Qigong LIU M D , Yan ZENG , Jiani LIU , Shan YE , Yongdong LI , Zaiying LU M D ,

《医学前沿（英文）》 2009年 第3卷 第3期   页码 284-286 doi: 10.1007/s11684-009-0062-1

摘要： To evaluate the role of nitric oxide in the biological effects of vascular endothelial growth factor (VEGF) and the possible mechanism of VEGF, the cultured vascular endothelial cells of rabbit aorta were divided into control group, VEGF-treated group and VEGF+ -nitro-L-arginine methyl ester (L-NAME)-treated group. The absorbance () value of vascular endothelial cells and the levels of prostaglandin (PGI), endothelin-1 (ET-1) and von Willebrand factor (vWF) in the supernatant were observed by water-soluble tetrazolium salt assay, radioimmunoassay and enzyme-linked immunosorbent assay. The values and PGI in VEGF-treated group and VEGF+L-NAME-treated group were higher than those in control group (<0.05 and <0.01). The ET-1 and vWF were significantly decreased in VEGF-treated group and VEGF+L-NAME-treated group compared with the control (<0.05 and <0.01). These results indicate that VEGF could promote the proliferation and secretion of PGI and inhibit the secretion of ET-1 and vWF in vascular endothelial cells and that L-NAME could inhibit the effect of VEGF partially. Nitric oxide is an important mediator in the process of stimulating proliferation and regulating secretion of vascular endothelial cells by VEGF.

关键词： vascular endothelial growth factor     nitric oxide     N-nitro-L-arginine methyl ester     vascular endothelial cells    

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Modeling of Ce(IV) transport through a dispersion flat combined liquid membrane with carrier P507

Liang PEI,Liming WANG,Zhanying MA

《环境科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 503-509 doi: 10.1007/s11783-013-0540-1

摘要： A mathematical model for the transport of Ce(IV) from hydrochloric acid solutions through dispersion flat combined liquid membrane (DFCLM) with contain 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (P507) as the carrier, dissolved in kerosene as the membrane solution have been studied. This process of facilitated transport, based on membrane technology, is a variation on the conventional technique of solvent extraction and may be described mathematically using Fick’s second law. The equations for transport velocity are derived considering the diffusion of P507 and its metallic complexes through the liquid membrane. In this work, the system is considered to be in a transient state, and chemical reaction between Ce(IV) and the carrier to take place only at the solvent–aqueous interfaces. Model concentration profiles are obtained for the Ce(IV), from which extraction velocities are predicted. The experimental and simulated Ce(IV) extractions showed similar tendencies for a high Ce(IV) concentration and acidity case.The model results indicate that high initial Ce(IV) concentrations and acidity both have detrimental effects on Ce(IV) extraction and stripping. The diffusion coefficient of Ce(IV) in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and the values are 6.31 × 10 m ·s and 31.2 μm, respectively. The results are in good agreement with experimental results.

关键词： Dispersion flat combined liquid membrane (DFCLM)     dispersion phase     feed phase     2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester     Ce (IV)    

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Expression and characterization of a CALB-type lipase from

Jiang-Wei Shen, Xue Cai, Bao-Juan Dou, Feng-Yu Qi, Xiao-Jian Zhang, Zhi-Qiang Liu, Yu-Guo Zheng

《化学科学与工程前沿（英文）》 2020年 第14卷 第5期   页码 868-879 doi: 10.1007/s11705-019-1889-x

摘要： A lipase from SRZ2 (SRL) with 73% amino acid sequence identity to lipase B (CALB) was cloned and overexpressed in . The recombinant SRL showed a preference for short-chain -nitrophenyl esters. It achieved maximum activity at pH 8.0 and 65°C for -nitrophenyl hexanoate (C6) with and / values of 0.14 mmol∙L and 1712 min ∙mmol∙L at 30°C, respectively. SRL displayed excellent thermostability and pH stability, retaining more than 79% of its initial activity after incubation at 60°C for 72 h and 75% at pH 3 to 11 for 72 h. It also maintained most of its activity in the presence of inhibitors and detergents except sodium dodecyl sulfate, and it tolerated organic solvents. SRL was covalently immobilized and successfully used for ethyl hexanoate synthesis in cyclohexane or in a solvent-free system with a high conversion yield (>95%). Furthermore, high conversion yield was also achieved for the synthesis of various short-chain flavor esters when high substrate concentrations of 2 mol∙L were applied. This study indicated that a CALB-type lipase from SRZ2 showed great potential in organic ester synthesis.

关键词： lipase     Sporisorium reilianum     biochemical characterization     short-chain flavor ester     solvent-free system    

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标题 作者 时间 类型 操作

Toughening of vinyl ester resins by two-dimensional MXene nanosheets

期刊论文

The prediction of adsorption isotherms of ester vapors on hypercrosslinked polymeric adsorbent

Liuyan WU,Lijuan JIA,Xiaohan LIU,Chao LONG

期刊论文

Reaction and characterization of crosslinking hyperbranched poly (amine-ester) with succine anhydride

XIAO Ling, WEI Xiuzhen, ZHU Baoku

期刊论文

用于锂离子电池的富醚/酯/氟黏结剂配方

Xianqing Zeng, Donglin Han, Zeheng Li, Hongxun Wang, Gu Wu, Yong Deng, Kai Liu, Li Xie, Chengdu Liang, Min Ling, Yuchuan Huang

期刊论文

Potential hybrid feedstock for biodiesel production in the tropics

Solomon GIWA,Oludaisi ADEKOMAYA,Collins NWAOKOCHA

期刊论文

Supercritical carbon dioxide extraction of CLA-ethyl ester

Yingdi CHEN, Peng XU, Jian CHENG

期刊论文

Ternary phase behavior of water microemulsified diesel-palm biodiesel

Nurul Atiqah Izzati MD ISHAK,Ismail Ab RAMAN,Mohd Ambar YARMO,Wan Mohd Faizal WAN MAHMOOD

期刊论文

Role of nitric oxide in biological effects of vascular endothelial growth factor

Qigong LIU M D , Yan ZENG , Jiani LIU , Shan YE , Yongdong LI , Zaiying LU M D ,

期刊论文

Modeling of Ce(IV) transport through a dispersion flat combined liquid membrane with carrier P507

Liang PEI,Liming WANG,Zhanying MA

期刊论文

Expression and characterization of a CALB-type lipase from

Jiang-Wei Shen, Xue Cai, Bao-Juan Dou, Feng-Yu Qi, Xiao-Jian Zhang, Zhi-Qiang Liu, Yu-Guo Zheng

期刊论文