JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 131
·期 19
·
IF 1.64
Huachuan Zhang,Min Li,Yuyuan Deng,Chengxi Zhang,Qichao Ran,Yi Gu
In this article, a kind of styrylpyridine-containing polybenzoxazine was obtained via the Knoevenagel reaction between benzaldehyde and methylpyridine groups. The benzoxazine monomer (MPBC) containing the benzaldehyde and methylpyridine groups was synthesized firstly and its structure was characterized by Fourier transform infrared (FTIR) spectra, 1 H NMR and 13 C NMR. With the aid of differential scanning calorimetry, FTIR, and photoluminescent tests, the interesting curing behaviors were probed. The results showed that the ring-opening polymerization occurred at lower temperature, and the Knoevenagel reaction further took place at elevated temperature. The amine and phenol moieties were bonded together to form the styrylpyridine structure. Due to these special crosslinking structures, the corresponding polybenzoxazine exhibited excellent thermal stability, and had a special high char yield of 74.5%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40823.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 34
·50843
·
IF 3.125
Xuefei Shao,Junnan He,Xuemei Zhao,Yubin Zheng,Nan Zheng
Cationic polyesters have been widely utilized as efficient gene delivery carriers. Their ability in binding genes was majorly based on the electrostatic effect between the positive charges of polymers and the negatives charges of genes. It has been well known that large numbers of positive charges on the polymers would lead to undesired toxicity although strong gene binding capability. It was of great interest to developed a polymer with reduced positive charges while enhanced gene condensation ability. In this work, a library of polyesters functionalized by zinc-coordinated-dimethylpyridinium amine (DPA-Zn) have been successfully prepared by the polycondensation method starting from dimethyl 1,3-acetonedicarboxylate and 10 diols, followed by the post-modification using dimethylpyridinium amine and zinc nitrate. The post-modification efficiency was systemically evaluated and the optimized functionalization efficiency could reach around 50%. The gene condensation ability of the targeting polymers was also evaluated using gel retardation assay and dynamic light scatting. The results indicated that DPA-Zn functionalized polyesters could bind gene into nanocomplexes with the sizes around 200 nm.
研究领域:
生物材料学
·
基因递送
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DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2024
·Vol. 171
·期 9
·096505
·
IF 3.1
Zhefei Zhao,Linlin Zhang,Minghao Chen,Ruopeng Yu,Xuyao Yao,Yinghua Xu,Youqun Chu,Xinbiao Mao,Huajun Zheng
Electrochemical selective dechlorination can be regarded as one of the most promising strategies for generating high-valued chemicals. In the electrochemical dechlorination process of 2-chloro-5-trichloromethylpyridine (TCMP), except the anticipated dechlorination products involving 2-chloro-5-dichloromethylpyridine (DCMP), 2-chloro-5-chloromethylpyridine (CCMP), and 2-chloro-5-methylpyridine (CMP), some unexpected oxygen-incorporated products (6-chloronicotinic acid (CNA) and 6-chloronicotinoyl methyl ester (MCN)) can be obtained. Consequently, understanding the electrochemical dechlorination behavior of TCMP is crucial. Our research revealed that the activated Ag electrodes in halide ion solution exhibit enhanced electrochemical activities for electrochemical dechlorination of TCMP, compared with the pure Ag owing to the increased active specific surface areas and charge transfer. Second, oxygen participation in the reaction is a necessary condition for the formation of oxygen-incorporated products. A 100% selectivity of oxygen-incorporated products can be obtained at the potential of −0.6 V vs Ag/AgCl. Conversely, insufficient oxygen may lead to the potential becoming the determining condition that affects the reaction pathways. A more negative potential (−1.2 V vs Ag/AgCl) is conducive to the formation of dechlorination products with 94.2% conversion and 100% selectivity. This study, for the first time, elucidates the electrocatalyst, atmosphere, and potential-dependent activity and selectivity for the two dechlorination pathways of TCMP.
研究领域:
环境科学
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电化学
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DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
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2024
·
IF 4
Jian-Jun Zhong,Lingling Zhao,Yuanxin Guo,Zhanming Li,Hua Ye,Huanan Guan,Zhiqiang Xing,Weiqing Wang
The coffee phytochemical trigonelline and its roasting products nicotinic acid and N -methylpyridinium represent an important class of bioactives that mediate the health benefits of coffee consumption. However, there is a paucity of methods for their simultaneous analysis in coffee beans, especially those affordable and reliable for widespread routine use. To improve this situation, an easy-to-use HPLC−UV method was developed in this study based on a reversed-phase/cation-exchange mixed-mode column showing unique chromatographic selectivity toward the polar and ionic analytes over the matrix components of coffee. The selectivity was achieved by using a decreasing acetonitrile gradient, which tuned the column to a cation-exchange/hydrophilic interaction (CEX/HILIC) mixed separation mode whilst minimizing its hydrophobic interaction capability. The method was assessed for figures of merit, giving limits of detection in coffee beans at around the 0.1 mg/100 g wet matter level, and verified for its applicability to a heterogeneous set of coffee bean samples differing in roasting degree and origin.
研究领域:
分析化学
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食品科学
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植物化学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
·
IF 7.4
Erkang Li,Jingwei Cao,Yujie Zhen,Jiajun Wei,Yingmin Yu
Wastewater from coking and pharmaceutical processes often contain a significant amount of 2-methylpyridine, which forms an azeotropic mixture with water. Effectively and cleanly separating 2-methylpyridine from wastewater while conserving energy and obtaining high purity products is an urgent challenge. In this study, ternary liquid-liquid equilibrium (LLE) data for the extraction of 2-methylpyridine from wastewater were measured using three distinct solvents at temperatures of 303.2 K, 313.2 K, and 323.2 K. The obtained ternary data were subsequently correlated with thermodynamic models (NRTL and UNIQUAC) to get relevant binary interaction parameters, bridging a gap in Aspen Plus simulations of 2-methylpyridine separation by octanol solvents. Furthermore, the GUI tool was used to validate these parameters and the results confirmed the reliability of the obtained parameters. It was observed that as the temperature increased, the extraction performance of all systems decreased, indicating that elevated temperature are not conducive to the extraction process. Among the various components, iso-octanol showed the highest separation factor indicating better extraction efficiency of 2-methylpyridine. Additionally, this study integrated quantum chemical calculations to reveal the interaction mechanisms between different solvents, 2-methylpyridine, and water at the microscopic level. The computational results indicated that iso-octanol exhibited the most robust binding affinity with 2-methylpyridine, suggesting that iso-octanol has more excellent extraction properties.
研究领域:
化学工程
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环境科学
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高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 18
·8705-8711
·
IF 9.931
Hao Xu,Qinming Wu,Yueying Chu,Jingang Jiang,Ling Zhang,Shuxiang Pan,Changsheng Zhang,Longfeng Zhu,Feng Deng,Xiangju Meng,Stefan Maurer,Robert McGuire,Andrei-Nicolae Parvulescu,Ulrich Müller,Feng-Shou Xiao
2,6-methyl-N-methylpyridinium, as a novel organic template, is employed for the synthesis of RTH aluminosilicate zeolite with a SiO2/Al2O3 ratio of 17.6. The amount of 2,6-methyl-N-methylpyridinium template, the Na2O/SiO2 ratio, the SiO2/Al2O3 ratio, and the H2O/SiO2 ratio in the starting gel significantly influence the crystallization of RTH zeolite. Several analytical methods such as XRD, SEM, N2 sorption, TG-DTA, DRIFT and NMR were employed for the characterisation of the obtained RTH zeolites and to understand the crystallization process with the new template. Very interestingly, the crystallization of RTH zeolite with the new template takes a very short time (12 h at 130 °C and 50 min at 240 °C) compared with conventional RTH zeolite synthesis reported in the literature (72 h at 130 °C). Theoretical calculations show that this novel organic template has lower interaction energies for zeolite cage space filling than those of the organic templates previously reported in the literature, which lead to stronger structural directing. Kinetic results show that the activation energy of this novel organic template is much lower than that of the traditional one. Catalytic tests show that copper exchanged RTH zeolite (Cu-RTH) exhibits good catalytic properties in the NH3-SCR reaction and the H-RTH zeolite catalyst has excellent selectivities for ethylene and propylene in MTO reactions.
研究领域:
催化材料
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化学工程
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环境科学
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高影响因子
PROCESS SAFETY PROGRESS
·
2017
·Vol. 37
·期 3
·355-361
·
IF 0.812
Min Hua,Min Qi,Xuhai Pan,Wendi Yu,Lu Zhang,Juncheng Jiang
Alkyl pyridine-N-oxide can decompose to pyridine which readily leads to explosion accident in air. Therefore, risk analysis and inherently safer design are necessary for this process. This article aims to study the thermal hazards of the process of 3-methylpyridine oxidized by hydrogen peroxide, and then the corresponding Inherently Safer Designs (ISDs) were proposed. The inherent hazards during the process were first qualitatively evaluated by Qualitative Assessment for Inherently Safer Design. Then, the reaction calorimeter was employed to analyze the thermal hazards of the target reaction. Meanwhile, the Integrated Inherent Safety Index methods were simplified to quantitatively estimate the level of inherent safety of the process. The results show that the potential risk of the process is 87.2% which is at the high risk level. Based on the hazard identification and assessment results, three ISDs, namely adding catalyst (ISD I), improving reaction condition (ISD II), and using a tubular (ISD III), were proposed to enhance the safety. Finally, combining comparative experiments with ISI methods, an effect evaluation model for ISD was established to verify the rationality of the ISDs. The results indicate that the reaction hazards are diminished when three ISDs are utilized in production process. The inherent safety level of the reaction is increased by 22.2%, 50.7%, and 31.8%, respectively. © 2017 American Institute of Chemical Engineers Process Process Saf Prog 37:355–361, 2018
研究领域:
化学工程
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安全科学
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高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 4.446
Shan Yuan,Miaomiao Jin,Chao Xu,Wencheng Yin,Mingsha Zhao,Mo Xian,Wei Liu
3-(Aminomethyl) pyridine (3-AMP) is a versatile compound for the synthesis of pharmaceuticals, agricultural chemicals and numerous polymers. Efficient and mild biocatalytic synthesis is often an excellent supplement to traditional chemical synthesis methods. However, there has been no report of biocatalytic 3-AMP synthesis. In this paper, 3-AMP was synthesized for the first time by using biocatalysts co-expressing carboxylic acid reductase from Neurospora crassa (ncCAR) and ω-transaminase from Ochrobactrum anthropi (OATA) in one pot. In addition, the metabolic pathway was optimized by knocking out the transcriptional dual regulator arcA , which resulted in a 90% increase in the yield of 3-AMP. Furthermore, efficient self-sufficient whole-cell bioconversion was established by optimization, achieving 93% yield and a 40.6 mM (4.4 g/L) titer of 3-AMP without additional carbon sources. This whole-cell bioconversion system was also suitable for the high-efficiency biocatalytic synthesis of other aromatic or heterocyclic primary amines, such as benzylamine, 2-furfurylamine, 4-fluorobenzylamine, 2,4-difluorobenzylamine and 2-(aminomethyl) pyridine. Being entirely biocatalytic, our one-pot procedure provides considerable advantages in terms of economic, environmental and safety impacts over reported chemical methods.
研究领域:
生物化学
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合成生物学
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生物技术
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DOI
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
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2023
·Vol. 52
·期 8
·921-939
·
IF 1.2
Guo Qiang,Lin Jinyuan,Yang Pengju,Jiang Yong,Zhang Binchuan,Zhu Longxin,Wang Xunqiu
Isobaric vapor–liquid equilibrium (VLE) data for 2-methylpyridine + 2-vinylpyridine binary systems have been measured using a dynamic circulation device with the pressure points 1.9 kPa, 4.0 kPa, and 5.3 kPa at temperature in the range from 302.8 to 348.5 K. The VLE data passed the thermodynamic consistency test by using L–W method, R–K method and Fredenslund method. The NRTL, Wilson and UNIQUAC models were used to fit the data and binary interaction parameters were obtained for the three models. For these models, the results showed that the calculated values of the model were in good agreement with the experimental values and could, thereby, be used for the design and optimization of distillation.
研究领域:
化学工程
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热力学
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DOI
高影响因子
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
·
2015
·
IF 1.406
L. Zhang,W.D. Yu,X.H. Pan,J.J. Fang,M. Hua,F.M. Chen,J.C. Jiang
The exothermic oxidation of 3-methylpyridine with hydrogen peroxide was analyzed by Reaction Calorimeter (RC1e) in semi-batch operation. Heat releasing rate and heat conversion were studied at different operating conditions, such as reaction temperature, feeding rate, the amount of catalyst and so on. The thermal hazard assessment of the oxidation was derived from the calorimetric data, such as adiabatic temperature rise (ΔT ad ) and the maximum temperature of synthesis reaction (MTSR) in out of control conditions. Along with thermal decomposition of the product, the possibility of secondary decomposition under runaway conditions was analyzed by time to maximum rate (TMR ad ). Also, risk matrix was used to assess the risk of the reaction. Results indicated that with the increase of the reaction temperature, the reaction heat release rate increased, while reaction time and exotherm decreased. With the increase of feeding time, heat releasing rate decreased, but reaction time and exotherm increased. With the amount of the catalyst increased, heat releasing rate increased, reaction time decreased and exothermic heat increased. The risk matrix showed that when the reaction temperature was 70 °C, feeding time was 1 h, and the amount of catalyst was 10 g and 15 g, respectively, the reaction risk was high and must be reduced.
研究领域:
化学工程
·
安全科学
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产品关联
DOI
高影响因子
TALANTA
·
2023
·
IF 6.1
Yatian Cao,Xiaolong Gong,Le Li,Huihui Li,Xuanming Zhang,Dong-Yu Guo,Fuxiang Wang,Qinhe Pan
Bacillus anthracis spores can make humans infected with vicious anthrax, so it is significant to detect their biomarker 2,6-pyridinedicarboxylic acid (DPA). The development of dual-modal methods for DPA detection that are more flexible in practical applications remains a challenge. Herein, colorimetric xylenol orange (XO) was modified on fluorescent CdTe quantum dots (QDs) for dual-modal detection of DPA through competitive coordination. After the binding of XO on CdTe QDs via coordination with Cd 2+ , CdTe QDs displayed quenched red fluorescence and the bound XO was presented as red color. The competitive coordination of DPA with Cd 2+ made XO released from CdTe QDs, causing the enhanced red fluorescence of CdTe QDs and the yellow color of free XO. On this basis, DPA was rapidly (1 min) quantified through fluorescent and colorimetric modes within the ranges of 0.1–5 μM and 0.5–40 μM, respectively. The detection limits for DPA were calculated as low as 42 nM and 240 nM, respectively assigned to fluorescent and colorimetric modes. The level of urinary DPA was further measured. Satisfactory relative standard deviations (fluorescent mode: 0.1%–10.2%, colorimetric mode: 0.8%–1.8%) and spiked recoveries (fluorescent mode: 100.0%–115.0%, colorimetric mode: 86.0%–96.6%) were obtained.
研究领域:
生物化学
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分析化学
·
医学诊断
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2017
·Vol. 83
·期 2
·467-477
·
IF 1.575
Fu Likang,Zhang Libo,Wang Shixing,Zhang Gengwei,Peng Jinhui
A new adsorbent was synthesized via functionalizing nano-silica with 4-(aminomethyl) pyridine for selective recovery of gold. The adsorbent was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and transmission electron microscopy, and BET (surface area and porosimetry analyzer). The results indicated that the maximum adsorption capacity of Au(III) was 55.5 mg/g at pH 4.0 and room temperature. The adsorption reaction was fairly rapid and reached equilibrium within 30 min. The adsorption processes of Au(III) were fitted well to the Langmuir isotherm model and adsorption kinetics of Au(III) followed the pseudo-second-order rate equation. The adsorption mechanism lies on the chelation and ion exchange between gold ions and amines/hydroxyl groups. The adsorbent had good reusability after five cycles. Moreover, 4-(aminomethyl) pyridine-Silica nanoparticles has a good selectivity in the adsorption of Au(III) from the coexisting ions. Therefore, 4-(aminomethyl) pyridine functionalized nano-silica could be of great potential as new adsorbent for the selective recovery of Au(III) from industrial effluents and waste e-products. Graphical
研究领域:
环境化学
·
材料科学
·
冶金工程
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污染控制
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资源回收
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DOI
高影响因子
危险品化学品经营许可证（带存储）