Journal of Flow Chemistry
·
2018
·Vol. 8
·期 3
·139-146
·
IF 1.658
Liu Yang,Zeng Changfeng,Wang Chongqing,Zhang Lixiong
We design a new continuous diazotization microreaction process in which concentrated acid and sodium nitrite solutions are used. We form oil in water (O/W) microdroplets by mixing amine with sodium nitrite aqueous solution, which react with mineral acid to make the diazotization. In this way, the formed particles are dispersed in the aqueous phase, which can flow with the main stream, and consequently are consumed. Then the fluid can smoothly flow without clogging in the microchannels and we can achieve continuous operation. We use aniline, o-methylaniline, m-methylaniline, and o-ethylaniline as the raw materials, 6 M HCl and 6.5 M H 2 SO 4 as the acid as well as sodium nitrite to demonstrate the feasibility. The resulting diazonium salts are converted to iodo-substitute aromatic compounds to measure the yield. The results show that, SIMM-V2 micromixer is efficient to form the emulsion. Mixing the microdroplets with acid in a co-axial flow way can prevent clogging. In hydrochloric acid medium, high reaction yield can be obtained when the reaction temperature is 4 °C and the residence time is 13–15 s. In sulfuric acid medium, high conversion of aromatic amine of up to 99% and yield of approximately 90% can be achieved at the reaction temperature of 9 °C and the residence time of 14–16 s. This process provides efficient continuous diazotization reactions using concentrated acid and sodium nitrite solutions, minimizing the production of waste water.
研究领域:
化学工程
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有机合成
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2013
·
IF 2.112
Chang Peng,Yuzi Xiong,Zhibo Liu,Fan Zhang,Encai Ou,Jiangtao Qian,Yuanqin Xiong,Weijian Xu
An efficient and convenient method is applied to introduce varieties of simple functionalities onto the graphene surface for the bulk preparation, which begins with pristine graphite that does not require initial oxidative damage of the graphene basal planes. Diazonium compounds functionalized reaction is demonstrated and it successfully prevented the aggregation of graphene for which providing solubility in high polar organic media or even in volatile solvents such as ethanol and acetone. This approach is complemented by the phenyl carboxylic diazonium salt functionalized graphene (PCFG) attachment of a symmetrically substituted zinc phthalocyanine (PCFG-Pc) using the amide reaction, which is used for the covalent introduction of a complex phthalocyanine molecule.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Linjie You,Weiguo Chen,Dongming Qi,Zhihua Cui,Sateesh Bandaru
Cotton fabrics, as both a polysaccharide and a high-molecular-weight polymer, are typically dyed with reactive dyes, which require a high amount of salt and produce significant colored effluent, increasing treatment complexity. This paper presents a novel and revolutionary reactive dyeing technique based on diazo pre-activation and coupling coloration of cotton fibers, which is distinct from conventional reactive dyeing methods. It demonstrates a room-temperature, salt-free reactive dyeing method to address problems like high energy consumption, significant salt usage, wastewater treatment challenges, the long duration from dye preparation to application, and the difficulty of recycling cotton fibers in reactive dyeing processes. This method combines dye preparation and dyeing by amination, diazotization, and coupling. It produces salt-free, room-temperature dyeing in <4 h, which is substantially less time than a standard reactive dyeing procedure that requires both dye synthesis and application. Furthermore, cotton fabrics can be endowed with bright, deep, and diverse colors, achieving superior colorfastness with ratings of 3–4 or more and K / S values exceeding 12. Moreover, dyed cotton fabrics can be easily decolorized by alkaline washing, producing alkaline washed cotton (AWC), while preserving their good whiteness and recyclable nature.
研究领域:
纺织科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2023
·
IF 3.6
Wen Li,Hexiang Wang,Yuan Zhang,Limin Zhao,Pengfeng Guo,Hua Cao,Xiang Liu
Pyridinium 1,4-zwitterionic thiolates were regarded as powerful and versatile building blocks to prepare nitrogen- and sulfur-containing heterocycles. Herein, we reported a copper-catalyzed formal [4 + 1] annulation of pyridinium 1,4-zwitterionic thiolates and diazo compounds without any additives to access a library of trifunctionalized indolizines in good yields. Besides, isoquinolinium 1,4-zwitterionic thiolates and imidazolium 1,4-zwitterionic thiolates were also applied to this formal [4 + 1] annulation reaction. Of particular note is that various functional groups such as −CO2R, −CO2NR2, −CF3, −CN, and −(O)P(OR)2 could be easily introduced into cycloaddition products indolizines by this strategy.
研究领域:
有机化学
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合成化学
✓ 已验证
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2020
·
IF 4.006
Xiaoying Guo,Xinyu Wang,Dongwei Huang,Jinjie Zhang,Dalun Xu,Wenge Yang,Qijie Hu,Zhongxiang Fang,Tao Huang
A new analytical method was developed to determine total purine content in fish meat. The analysis principle is that total purine extracted from fish meat are turned into uric acid by diazotization reaction and xanthine oxidase reaction. Then, the content of uric acid is measured by surface-enhanced Raman spectroscopy (SERS). The results showed that the optimal conditions for the diazotization reaction were at 60 °C for 40 min, using 0.16 M HCl, and 3.00 g/L NaNO 2 . The optimal xanthine oxidase reaction conditions were using 100 U/L xanthine oxidase, conducting at 30 °C and pH 7.0 for 40 min. The calibration curve established at the characteristic Raman peak of 631 cm −1 had a good linear relationship (R 2 = 0.9864). The recovery rate was between 101.7% and 105.0%. Therefore, the total purine content in the fish meat can be quantitatively determined with this new method.
研究领域:
分析化学
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食品科学
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生物化学
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产品关联
DOI
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2017
·Vol. 28
·期 8
·1475-1482
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IF 1.198
Xu Zhiqun,Wu Qiao,Duan Yunjian,Yang Meixia,Ou Minrui,Xu Xiaoping
Bisphenol A (BPA) is an industrial material which can lead to endocrine disorders. In this work, a simple and sensitive spectrophotometric method for determination of BPA using diazotization-coupling reaction was presented. To achieve the best performance of the developed method, the experimental parameters were optimized in terms of reagent concentration, reaction time, pH, and temperature. Under the optimal conditions, the absorbance increased linearly with the increasing concentration of BPA in the range of 0.16-10.4 µg mL-1 with the correlation coefficient of 0.9991 and the detection limit of 0.05 µg mL-1. Results achieved with the spectrophotometric method were compared with those obtained using high performance liquid chromatography (HPLC) method. The proposed method was successfully applied to determine BPA in milk and water bottle samples and satisfactory results were obtained, which make it very suitable for routine analysis of BPA in quality control laboratories.
研究领域:
分析化学
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环境科学
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食品安全
✓ 已验证
产品关联
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2018
·
IF 2.826
Fajun Wang,Jinpei Huang,Jianhong Xu
Azo dye is a kind of synthetic dye containing azo group (Ar-N=N-Ar). In this paper, an efficient process intensification for the continuous synthesis of azo dye is developed by using a microreactor system. Firstly, the reaction conditions of azo-coupling reaction were optimized and a microreactor was utilized as the mixing and reacting unit. 1- (4- sulfonicphenyl) -3- methyl -5- pyrazolone was the coupling component and aniline was the diazo component. The results show that the yield of azo-coupling reaction was higher than 96% under optimized condition. Then, the reaction conditions of diazotization were optimized by orthogonal experiments in a microreactor system. Combined with the optimization of azo-coupling reaction conditions, the optimal conditions of continuous-flow synthesis of azo dyes in microreactoras were determined. Then, four model azo dyes were synthesized by the continuous method in microreactors. The yields of No. 1, No. 2 and No. 4 azo dyes were above 96% and the yield of No. 3 azo dye was above 90%. Finally, the commercial azo dyes were synthesized continuously in microreactors and the yields were above 94%. The continuous-flow synthesis of azo dyes in a microreactor system has great potential in industrial applications.
研究领域:
化学工程
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染料化学
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过程强化
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2025
·
IF 3.5
Lei Li,Xinyu Ye,Huaixi Liu,Rongwen Lu,Bingtao Tang,Shufen Zhang
Integrating the diazotization and coupling reactions in solid–liquid heterogeneous systems to achieve large-scale, multistep continuous flow synthesis of water-soluble azo dyes remains a significant challenge. During the diazotization process of water-soluble azo dyes, considerable diazonium salt may precipitate, posing potential safety risks. In this study, we established a continuous dynamic tubular reaction system to achieve the multistep continuous heterogeneous synthesis of C.I. Reactive Red 195, a representative water-soluble azo dye. The optimal conditions for continuous diazotization and coupling reactions were determined, achieving a high throughput of 120 L/h and a yield of up to 736 kg/day. The purity of the synthesized dye increased by 20% compared to the commercial C.I. Reactive Red 195, with the K/S value rising from 19.07 to 22.16, indicating enhanced dyeing performance. Density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations show that 2-naphthylamine-1,5-disulfonic acid diazonium salt (NADA-DS) spontaneously aggregates into stable clusters due to dispersion forces, which leads to precipitation. Furthermore, the thermal stability, impact sensitivity, explosive propagation, and decomposition activation energy of NADA-DS were investigated. The severity and possibility of thermal runaway during the continuous diazotization process are classified as level 1. The risk matrix indicates that the continuous diazotization process risk is acceptable, with the Stoessel criticality diagram categorizing the hazard level as grade 1, signifying a low level of risk. This study promotes safer, more efficient, and sustainable production of water-soluble azo dyes.
研究领域:
化学工程
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材料科学
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安全科学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2024
·Vol. 15
·期 8
·775-782
·
IF 4.1
Zixuan Zhu,Xinyi Pan,Yaning He
Diazonium chemistry serves as a versatile and facile approach for surface modification. In this work, we propose a strategy of one-step photo-induced modification of carbon nanotubes (CNTs) with polymeric diazonium salts. The PEGylation process was conducted with diazonium-terminated poly(ethylene glycol) (mPEG-N2+) or PEG-based block polymeric diazonium salts (PEG-b-PSN2+) under irradiation with 275 nm ultraviolet light. The covalent functionalization of PEG-CNTs was verified by transmission electron microscopy, thermogravimetric analysis and Fourier-transform infrared spectroscopy. A thorough investigation involving the impact of varied functionalities of PEG-based polymeric diazonium salts on the PEGylation rate as well as polymer content is presented. It was concluded that the block copolymer with moderate functionality showed great potential in this strategy. On the other hand, hydrophobic modification with PS-based block polymeric diazonium salts (PS-b-PSN2+) was also carried out successfully. Herein, we present a novel strategy for the preparation of CNT–polymer composites in a one-step route, notable for its universality in both aqueous and organic solutions.
研究领域:
材料科学
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化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Biosensors-Basel
·
2021
·Vol. 11
·期 8
·280
·
IF 5.519
Mengzhu Wang,Peng Liu,Hengjia Zhu,Bangxiang Liu,Xiangheng Niu
Due to the great threat posed by excessive nitrite in food and drinking water to human health, it calls for developing reliable, convenient, and low-cost methods for nitrite detection. Herein, we string nanozyme catalysis and diazotization together and develop a ratiometric colorimetric approach for sensing nitrite in food. First, hollow MnFeO (a mixture of Mn and Fe oxides with different oxidation states) derived from a Mn-Fe Prussian blue analogue is explored as an oxidase mimic with high efficiency in catalyzing the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation to blue TMBox, presenting a notable signal at 652 nm. Then, nitrite is able to trigger the diazotization of the product TMBox, not only decreasing the signal at 652 nm but also producing a new signal at 445 nm. Thus, the analyte-induced reverse changes of the two signals enable us to establish a ratiometric colorimetric assay for nitrite analysis. According to the above strategy, facile determination of nitrite in the range of 3.3–133.3 μM with good specificity was realized, providing a detection limit down to 0.2 μM. Compared with conventional single-signal analysis, our dual-signal ratiometric colorimetric mode was demonstrated to offer higher sensitivity, a lower detection limit, and better anti-interference ability against external detection environments. Practical applications of the approach in examining nitrite in food matrices were also verified.Keywords:nitrite;ratiometric colorimetric detection;nanozyme catalysis;diazotization reaction;food analysis
研究领域:
分析化学
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食品科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MEASUREMENT
·
2025
·
IF 5.6
Jintao Liang,Zhenshun Wei,Qing Huang,Jianlu Liang,XiuChuan Zhao,Zhide Zhou,Guiyin Li
Tea polyphenols are a general term for the total phenolic compounds in tea. Tea polyphenols play a crucial role in the quality of tea. Rapid detection of tea polyphenols is essential for tea harvesting and breeding. In this paper, a rapid method for the detection of tea polyphenols is presented based on diazotization coupling (DC) reaction and flow batch analysis system (FBAS). The tea polyphenols detection based on DC reaction can avoid interference from non-phenolic substances and improve detection accuracy. Meanwhile, FBAS for sample injection can shorten the analysis time, reduce the reagent consumption and improve the sensitivity. Experimental results demonstrate that absorbance values exhibit linearity with gallic acid concentrations in the range of 5 to 60 μg/mL, with a linear equation of y = 0.0279x + 0.0613 (R 2 = 0.9993) and a limit of detection (LOD) of 0.215 μg/mL (S/N=3). The method was applied to the detection of tea polyphenols in tea samples, with relative standard deviations (RSD) ranging from 0.326% to 0.659%. The DC-FBAS method has a high potential application with the requirements of portable, cost-effective, and highly precise on-site tea polyphenols detection.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Flow Chemistry
·
2021
·Vol. 11
·期 4
·843-853
·
IF 2.786
Jiang Xinxiang,Li Guangxiao,Liu Saier,Song Yang,Su Yuanhai
The process characteristics of two main steps in the preparation of 4-nitrobiphenyl (4-NBP) from 4-nitroaniline (PNA) were clearly revealed by applying two continuous-flow microreactors. The first step was the synthesis of 4-nitrobenzene diazonium tetrafluoroborate (4-NBDT) through the diazotization reaction. The reaction temperature, the residence time, and the molar ratio of different reactants were investigated to achieve optimal reaction conditions with the highest yield of 4-NBDT. Notably, the yield of 4-NBDT reached 97% at 25 °C only in 2.3 s with the optimal molar ratio of HBF 4 , NaNO 2 and PNA (i.e., 2.72:1.05:1). The second step was the Suzuki-Miyaura cross-coupling reaction, in which HNO 3 was used to transform the reaction system into a homogeneous state. The effects of mixing performance, the molar percentage of Pd(OAc) 2 to 4-NBDT, the reaction temperature and the residence time on the Suzuki-Miyaura cross-coupling reaction were investigated systematically. With the molar percentage of Pd(OAc) 2 to 4-NBDT of 1 mol%, the yield of 4-nitrobiphenyl (4-NBP) was optimized to 99% in just 13 min at 25 °C. This study demonstrated the excellent potential of utilizing the continuous-flow microreactor for the diazotization and the following Suzuki-Miyaura cross-coupling reaction.
研究领域:
有机化学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）