Chemistry-An Asian Journal
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2015
·Vol. 10
·期 12
·2725-2732
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IF 4.587
Shi Huang,Xiujuan Qi,Wenquan Zhang,Tianlin Liu,Qinghua Zhang
Graphical Rocket man : New [imidazolyl−amine−BH 2 ]-cation-based hypergolic ionic liquids exhibit hypergolic properties upon contact with an oxidizer. Of the new ionic liquids, seven dicyanamide-based ionic liquids are water-stable and have ID<50 ms. Compared to traditional hypergolic ionic liquids, they exhibited shorter ID times and higher densities, thus suggesting their potential application in liquid bipropellant fuels or formulations. The application of hypergolic ionic liquids as propellant fuels is a newly emerging area in the fields of chemistry and propulsion science. Herein, a new class of [imidazolyl−amine−BH 2 ] + -cation-based ionic liquids, which included fuel-rich anions, such as dicyanamide (N(CN) 2 − ) and cyanoborohydride (BH 3 CN − ) anions, were synthesized and characterized. As expected, all of the ionic liquids exhibited spontaneous combustion upon contact with the oxidizer 100 % HNO 3 . The densities of these ionic liquids varied from 0.99–1.12 g cm −3 , and the heats of formation, predicted based on Gaussian 09 calculations, were between −707.7 and 241.8 kJ mol −1 . Among them, the salt of compound 5 , that is, (1-allyl-1H-imidazole-3-yl)−(trimethylamine)−dihydroboronium dicyanamide, exhibited the lowest viscosity (168 MPa s), good thermal properties ( T g <−70 °C, T d >130 °C), and the shortest ignition-delay time (18 ms) with 100 % HNO 3 . These ionic fuels, as “green” replacements for toxic hydrazine-derivatives, may have potential applications as bipropellant formulations.
研究领域:
化学
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推进科学
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产品关联
DOI
PubMed
高影响因子
TALANTA
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2014
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IF 3.511
Jiang Liu,Han Song,Jie Liu,Yuan Liu,Le Li,Hui Tang,Yingchun Li
In this study, a rapid and accurate determination strategy was established for simultaneous measurement of melamine (MLM) and dicyandiamide (DCD) directly in powdered milk by coupling molecularly imprinted solid-phase extraction (MISPE) with high performance liquid chromatography (HPLC). A novel double-template technique was adopted for preparing SPE packing agent and the obtained double-templated (MLM and DCD) molecularly imprinted polymers (MD-MIPs) was characterized by Fourier-transform infrared spectroscopy and scanning electron microscope (SEM). The molecular recognition ability and the binding capability of the as-prepared polymers towards MLM and DCD were evaluated via static and dynamic binding tests, and it was found that the MD-MIPs showed better affinity and selectivity for both templates compared with single-templated MIPs and non-imprinted polymers (NIPs). An approach based on MISPE and HPLC was then developed and optimized to detect MLM and DCD in powdered milk. The detection limit of the method ( S / N =3) were 0.13 μg/g for MLM and 0.07 μg/g for DCD, and the relative standard deviation (RSD) of intra-day and inter-day determination for MLM was 3.3% and 4.7%, and 3.5% and 5.9% for DCD. The recoveries in MLM and DCD analysis at three spiked levels were 93.1–100.1% and 75.7–82.5%, respectively, with all RSD less than 5.2%.
研究领域:
分析化学
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食品安全
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DOI
高影响因子
IONICS
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2024
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IF 2.4
Zhang Jingchun,Wang Qiqi,Chen Haoyuan,Zhang Yilin,Deng Yupei,Wang Ying,Zhao Huimin,Zhu Yu,Wang Guowei,Zhuang Linghua
It is found that ester introduction into imidazolium or pyridinium cations can significantly improve the biodegradability property of ionic liquids and also influence the viscosity and the toxicity of ionic liquids. Ionic liquids based on dicyanamide anion reveal good electrochemical properties. Four chloride and dicyanamide ionic liquids with ester groups were prepared, and the effect of anion and cation structure of ionic liquids on electrical conductivity/electrochemical stability window was discussed from experimental studies and density functional theory (DFT) simulations. The introduction of the ester group in imidazolium cation decreased the refractive index and electrical conductivity, while increasing the electrochemical stability window of ionic liquids. The refractive index, electrical conductivity, and electrochemical stability window values decreased with the increase of the alkyl chain length of the ester group from ethyl to butyl. The refractive index values of chloride imidazolium ionic liquids were higher than those of dicyanamide ionic liquids, while the electrical conductivity and electrochemical stability window values of dicyanamide ionic liquids were much higher than those of chloride ionic liquids. DFT simulations revealed that ester introduction in imidazolium cation decreased the average hydrogen bond length and increased the cation–anion interaction. The average hydrogen bond length of chloride and dicyanamide ionic liquids increased with the increase of the alkyl chain length of the ester group from ethyl to butyl, while the absolute interaction energy (Δ E ) of chlorine and dicyanamide ionic liquids decreased with the increase of the alkyl chain length of the ester group from ethyl to butyl. DFT simulations demonstrated that ionic liquid structure (ester chain length and anion) was closely related to the electrical conductivity and electrochemical stability window properties of ionic liquids. These results will shed light on the design and optimization of functional ionic liquids as electrolytes for renewable energy and energy storage applications.
研究领域:
材料科学
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理论化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2016
·Vol. 134
·期 8
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IF 1.866
Defa Hou,Hanbing Ma,Xiuyun Li,Jie He,Huiwei Liao
A novel easily curing system of 2,2- bis (4-cyanatophenyl) propane(BACY) was prepared by employing 4,4′-(Hexafluoroisopropylidene) Diphenol (BPAF) as modifier. The curing efficiency of BPAF was evaluated by means of differential scanning calorimetry (DSC) and Fourier translation infrared spectroscopy analysis (FTIR). It was found that the exothermic peak temperature ( T p ) was 168 °C when the content of BPAF/BACY was 15/85 by weight, while the temperature of BACY was 215 °C under the same conditions when trace of cobalt(III) acetylacetonate(CoAt(III)) was added. Besides, BPAF/BACY system owned outstanding properties including excellent curing characteristics, high shear strength, remarkable dielectric properties and high thermal stability in contrast to BACY, 4,4′-(1-methylethylidene) bisphenol(BPA)/BACY, and nonylphenol(NoP)/BACY systems. Moreover, the properties of cured BPAF/BACY modified by different proportions of BPAF were studied in detail. It was shown that moderate BPAF was conducive to most properties of polycyanurate, and the optimal proportion of BPAF/BACY was 15/85 by weight. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44518.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
Journal of Food Measurement and Characterization
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2024
·Vol. 18
·期 3
·2420-2427
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IF 2.9
Chen Fazheng,Jiang Zhiyong,Yang Shiyou
In the present work, the surface of glassy carbon electrode (GCE) was modified with graphitic carbon nitride (g-C 3 N 4 ) prepared from the freeze-dried dicyandiamide. The physiochemical properties and electrocatalytic ability of the g-C 3 N 4 nanosheets have been well investigated. Differential pulse voltammetry (DPV) method was employed to determine bisphenol A (BPA) using the modified GCE. To obtain the conditions for maximum DPV response, the effects of experimental parameters, such as the solution pH and nano-sized modifier concentration, were investigated and optimized. The proposed BPA sensing assay indicated a linear range of 0.01 to 75.0 µM under optimal conditions, with a detection limit of 9.0 nM. The anti-interference investigations revealed that the presence of various organic and inorganic species did not hinder the accurate measuring of BPA. In addition, the presented modified electrode exhibited satisfactory results in terms of stability and reproducibility. The obtained results also confirm the efficacy of the g-C 3 N 4 nanocatalyst for determination of BPA in different real samples (drinking water, milk and orange juice) with satisfactory recovery values (95.6–104.0%). The suggested assay provides a powerful sensing platform for the fast and sensitive analysis of BPA in food samples.
研究领域:
分析化学
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材料科学
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电化学
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食品安全
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环境监测
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DOI
高影响因子
ENVIRONMENTAL POLLUTION
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2022
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IF 9.988
Andong Wang,Dongsheng Zou,Zhihong Xu,Bin Chen,Xiaopeng Zhang,Falin Chen,Manyun Zhang
Repeated and high-dose carbendazim applications have caused serious soil carbendazim contamination, and eco-friendly and economical approaches have been suggested to promote carbendazim removal in agricultural soil . Spent mushroom substrate (SMS) is a special recycled resource after harvesting mushrooms and can be utilized in contaminated soil amendment. The SMS application into agricultural soil might increase antibiotic resistance gene abundances, and the health risks of SMS application might be reduced with reasonable management to adjust the related electron transport of soil nitrification or denitrification. In this study, the SMS and nitrification inhibitor dicyandiamide were used to remediate agricultural soil contaminated with the carbendazim, and the carbendazim contents, soil microbial biomass, activities and community and human disease genes were determined. Compared to the control treatment, the combined applications of SMS and dicyandiamide significantly decreased soil carbendazim content by 38.14% but significantly enhanced soil β -glucosidase, chitinase, arylsulfatase, urease and electron transfer system activities. The relative abundances of Proteobacteria and Actinobacteria were increased by 11.0% and 8.2% with the SMS application, respectively. The carbendazim residues were negatively correlated with the soil pH, electron transfer system activities and relative abundances of Proteobacteria and Actinobacteria. The relative abundances of human disease genes were also dramatically increased with the SMS application, but compared to the SMS alone, extra dicyandiamide application significantly reduced the relative abundances of human disease genes in soils. The SMS applications into fungicide-contaminated soils could generate double-edged sword effects of facilitating fungicide dissipation but leading to potential health risk increase, while applying the dicyandiamide with SMS might be an effective strategy to decrease the negative effect of health risk.
研究领域:
环境科学
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土壤学
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微生物学
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生态毒理学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2023
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IF 8.7
Yan Wang,Xinlin Zhao,Negar Omidvar,Mengting Liu,Dongsheng Zou,Manyun Zhang
Fungicides and nitrogen (N) fertilizers are essential to maintain plant yield in current intensive agriculture. Percarbamide is a novel type of N fertilizer with strong oxidizing property, and the nitrification inhibitor is widely used in agricultural production. It may be feasible to apply percarbamide and nitrification inhibitor as N management to promote fungicide dissipations in soil-plant system. This study quantified the effects of percarbamide and nitrification inhibitor dicyandiamide (DCD) and 3, 4-dimethylpyrazole phosphate (DMPP) on carbendazim residues, and microbial communities of soil-plant systems, and relationships among carbendazim residues, soil and endophytic microbial communities and plant yields were also comprehensively quantified. Compared with the control, the percarbamide significantly reduced soil carbendazim residues by 29.4% but enhanced the lettuce yield by 28.0%. Soil carbendazim residues were significantly and negatively correlated with the soil total N and NO 3 − -N contents. Soil microbial community structures and co-occurrence networks were more sensitive to N management than their endophytic counterparts. In comparison to the percarbamide alone, the DCD significantly increased the nodes of soil fungal community co-occurrence network which were positively correlated with the plant yield. The DCD outweighed DMPP in increasing the lettuce yield and soil fungal community stability and reshaping soil bacterial community structure. Our study suggested that soil microbial communities were more sensitive to percarbamide and nitrification inhibitor applications than their endophytic counterparts under fungicide pressure and that the DCD outweighed DMPP in reshaping microbial communities. The integrated applications of percarbamide and nitrification inhibitors were promising soil N management strategies to promote fungicide removal and stimulate microbial community in the soil-plant systems.
研究领域:
农业科学
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土壤学
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微生物学
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环境科学
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植物科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）