BIORESOURCE TECHNOLOGY
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2019
·
IF 6.669
Yongxing Chen,Xiudi Cao,Shan Zhu,Fengshou Tian,Yongyan Xu,Chaosheng Zhu,Lin Dong
The effect of Na 2 CO 3 , Fe and Na 2 CO 3 + Fe during hydrothermal liquefaction (HTL) of wheat stalk with different temperature and reaction time was investigated in this study. The results indicated that Na 2 CO 3 + Fe can promote the cracking of wheat stalk compared with Na 2 CO 3 or Fe. Meanwhile, higher temperature favored the decomposition of wheat stalk and formation of heavy bio-oil. The highest heavy bio-oil yield was 24.25 wt% and the maximum liquefaction conversion rate was 89.45 wt% in system of Na 2 CO 3 + Fe at 270 °C. The analysis results indicated that longer reaction time could promote liquefaction conversion especially for heavy bio-oil with Na 2 CO 3 + Fe during the process of HTL. GC–MS, UPLC-MS and FT-IR analysis indicated that the major organic compounds in heavy bio-oil were aromatic compounds , alcohols, ketones, alkanes, and aldehydes, among of them aromatic compounds were the most prevalent.
研究领域:
能源植物学
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环境科学
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DOI
高影响因子
Natural Product Communications
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2015
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IF 0.906
Jian-Wei Dong,Le Cai,Yun Xing,Jing Yu,Zhong-Tao Ding
2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation (ABTS•+) is a stable free radical frequently used for estimating the total antioxidant capacity (TAC) of natural products. The existing methods for ABTS•+ radical-scavenging activity assays are diverse in pre-diluting solvents and reaction time, which lead to errors in the TAC estimations. To develop an effective and universal method for estimating the ABTS•+ capacity accurately and reasonably, five pre-dilution solvents [methanol, ethanol, phosphate buffer (Na2HPO4-NaH2PO4, 200 mM, pH = 7.4), PBS buffer (Na2HPO4-NaH2PO4-NaCl, 200 mM, pH = 7.4), and distilled water] and different reaction times were investigated in ABTS•+ assays of five typical antioxidants. The results showed that the solvent effects were very significant. When using different pre-diluting solvents, different detection wavelengths should be selected. ABTS-+ assay could be measured within 2–10 min to obtain a rough result, which was mostly 6 min in the literature. However, full and accurate evaluation of antioxidant reactivity rather than capacity requires recording ABTS•+ loss continuously during the whole reaction period. The present study makes a recommendation for estimating the ABTS•+ capacity accurately and reasonably.
研究领域:
生物化学
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分析化学
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DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2019
·Vol. 99
·期 10
·4801-4807
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IF 2.422
Weijun Chen,Ruiling Lv,Wenjun Wang,Xiaobin Ma,Aliyu Idris Muhammad,Mingming Guo,Xingqian Ye,Donghong Liu
BACKGROUND The functional properties of whey protein isolate (WPI) are sensitive to pH, ionic strength, and temperature. This prevents its application in various food systems and processing technologies. The conjugation of proteins with polysaccharides via the Maillard reaction is an efficient method to improve the functionality of proteins. The purpose of this work was to conjugate gum acacia (GA) with WPI via the dry-heating Maillard reaction and to investigate the effect of reaction time on the physicochemical and functional properties of WPI-GA conjugates. RESULTS Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance size exclusion chromatography confirmed the formation of higher molecular weight conjugates. The degrees of glycation for WPI-GA conjugates incubated for 1, 3, 5, and 7 days were 28.14%, 44.98%, 49.50%, and 51.20%, respectively. The glycation reaction reduced the surface hydrophobicity and fluorescence intensity of WPI significantly ( P < 0.05). Functional properties of the conjugates, such as solubility, stability against heat-induced insolubility, and emulsion properties were all superior to the control WPI. However, a reaction time longer than a day resulted in a high degree of browning and decreased the functionality of the conjugate significantly ( P < 0.05). CONCLUSION The results indicated that conjugation of WPI with GA can be a promising way to enhance its functional properties. However, the reaction time suitable for producing conjugates with superior functional properties was not necessarily the highest glycation degree that could be reached. © 2019 Society of Chemical Industry
研究领域:
食品科学
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生物化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2019
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IF 5.107
Bingchen Chen,Chao Wan,Xueting Kang,Mingqing Chen,Chunfang Zhang,Yunxiang Bai,Liangliang Dong
In this study, a facile and scalable in situ growth method was used to synthesize ZIF-8@GO composites. The obtained ZIF-8@GO were blended with a CO 2 -philic, comb copolymer yielding a series of mixed matrix membranes (MMMs), which were evaluated for their performance in separation of CO 2 /N 2 . The effect of reaction time for ZIF-8@GO composites on gas separation performance was systematically investigated. Pure and mixture gas permeation tests indicated that MMM with ZIF-8@GO by in situ growth for 6 h exhibited the largest improvement (CO 2 permeability: 475 Barrer and CO 2 /N 2 selectivity: 58.2) compared with pure polymers, with the overall CO 2 /N 2 separation performance exceeding the 2008 polymer upper bound. Our strategy that the in situ growth of ZIF-8 on GO provides an effective way to design MMMs with well filler dispersion, structural features and separation performance.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
GREEN CHEMISTRY
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2024
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IF 9.3
Zifei Yan,Jian Deng,Jiaxin Tian,Guangsheng Luo
Sodium azide production suffers from safety hazards and environmental pollution rooted in the reduction reaction between alkyl nitrites and hydrazine hydrate. To enhance this heterogenous reaction, nitrites synthesized from small molecule fatty alcohols are widely used to increase its solubility in the aqueous phase. Despite these efforts, the reaction time of several hours remains necessary, and the high volatility of alkyl nitrites results in VOC emissions and safety concerns. Here, a nitrite synthesized from benzyl alcohol was used as an alternative. The aryl group provides a conjugated effect that stabilizes the transition state and reduces activation energy, thus reducing the reaction time from several hours to 20 minutes. Moreover, the higher boiling point of benzyl nitrite eliminates VOC emissions and safety problems, and the lower solubility of benzyl alcohol ensures that it can be recycled without distillation. A complete reaction mechanism was proposed based on the characterization of gaseous side products and active azo intermediates. The side reaction can be inhibited by increasing the relative concentration of hydrazine to nitrite in the organic phase. This work provides a straightforward and practical method to address potential challenges in azide production and contributes to the understanding of the aminolysis mechanism of nitrite esters.
研究领域:
化学合成
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环境科学
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安全工程
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DOI
高影响因子
ACTA PHYSICO-CHIMICA SINICA
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2016
·Vol. 32
·期 5
·1267-1272
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IF 0.844
WANG Han,WANG Xiao-Min
Because of their low toxicity and excellent water-solubility, graphene quantum dots have been highly anticipated for use in cellular imaging. However, their limited optical properties are hampering this use. To address this issue, graphene quantum dots surface passivated by branched
polyethylenimine (GQDs-BPEI) were proposed in this paper. We discussed optical properties when prepared under different conditions including reaction time, temperature, and pH value. The results indicate that GQDs-BPEI prepared at pH 12, at a temperature of 200 °C, and with a 20 h reaction
in an autoclave can achieve a higher UV absorbency and better PL properties with a high quantum yield.
研究领域:
材料科学
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纳米技术
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光学
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生物医学工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 17
·22024-22034
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IF 2.478
Li Hong,Jiao Jinxu,Ye Qi,Wu Zhixin,Luo Donglian,Xiong Dehua
Quantum dots (QDs) attract extensive attention because of their excellent optoelectronic performance. However, few research has been done on the synthesis of core–shell QDs by one-step thermal injection. Here the CdSe/ZnS core–shell QDs were successfully synthesized by a one-step thermal injection method. The synthesis process of CdSe/ZnS core–shell QDs was investigated from two aspects of reaction time and oleic acid dosage. The results suggest that the reaction time and the dosage of oleic acid have important effects on the optical properties of CdSe/ZnS core–shell QDs. The action mechanism of oleic acid was also explained in this paper. Moreover, highly efficient green quantum dot light-emitting diodes (QLEDs) were fabricated with CdSe/ZnS core–shell QDs on ITO glass substrate by rotary coating method. The minimum starting voltage of 1.91 V and the maximum brightness of 12,057 cd m −2 were achieved in the QLEDs. This study is of great significance for the development of the synthesis of core–shell QDs by one-step thermal injection and QLEDs.
研究领域:
材料科学
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纳米技术
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光电技术
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半导体物理
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DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 80
·65575-65582
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IF 3.84
Jian Wu,Yuxuan Liang,Pengpeng Bai,Shuqi Zheng,Liqiang Chen
Pyrite FeS2 microspheres with an average size of approximately 1.1 μm were successfully synthesised in high yield via a facile and efficient microwave-assisted method. X-ray diffraction patterns and high-resolution transmission electron micrographs showed that the microspheres had a pure single crystalline phase. Scanning electron micrographs and transmission electron micrographs illustrated that the microspheres were uniform and well-distributed. The absorption spectra of the as-obtained microspheres showed that pyrite exhibited high absorbance in the visible region. The surfactants influenced the phase, morphology and absorption property of the products. Long reaction time allowed the formation of uniform pyrite FeS2 microspheres with smooth surfaces. The microwave-assisted method yielded products with better morphology and absorption properties than the high-pressure solvothermal method.
研究领域:
材料科学
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化学
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纳米技术
✓ 已验证
DOI
高影响因子
Journal of Energetic Materials
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2024
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IF 1.7
Ying Wu,Yong Liu,Shuai Hou,Qizhi Zhao,Han Gao,Xiao Yan
4,4’-Azo-1,2,4-triazole (atrz) is a new high nitrogen energetic material with high energy density, high gas yield and wide application prospects, but the low synthesis temperature and long time are the main reasons limiting its application. To achieve efficient synthesis of atrz, the double drop synthesis method was designed to solve the problem of unstable concentration of oxidant (HClO) due to batch feeding. The reaction temperature, reaction time, and molar ratio of reactants of n(4-amino-1,2,4-triazole):n(ClO−) were studied and optimized using the single factor variable method; Characterization and analysis of atrz using theoretical calculations with elemental analysis, infrared spectroscopy, crystal morphology, and nuclear magnetic resonance; The thermal properties and stability of atrz were tested and analyzed using TG-DTA. The results showed that the reaction time of the double drop synthesis method was shortened from 5 hours to 1.5 hours under the conditions of similar yield, and the efficiency was increased by 2.3 times. The optimized process was a reaction temperature of 5°C-10°C, reaction time of 1.5 hours, n(4-amino-1,2,4-triazole):n(ClO−) of 1:2, and the yield reached 73%. The product was white, needle-like crystals, which were determined to be atrz by means of characterization and theoretical calculations. Atrz’s decomposition peak temperature is 309.0°C, and when the temperature is below 271.7°C, atrz is thermally stable. The activation energies of atrz calculated by Kissinger and Flynn-Wall-Ozawa methods were 195.0 kJ·mol−1 and 194.6 kJ·mol−1.
研究领域:
化学
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材料科学
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能材料
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理论计算
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热分析
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DOI
高影响因子
危险品化学品经营许可证（带存储）