CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Luyan Yao,Changming Ke,Jinhua Zhang,Yuanbing Li,Bingqiang Han,Jingran Wang
Ti–Si–Fe alloys extracted from high-titanium blast furnace slag were utilized to replace part of the silicon powders, and then nitride/oxynitride bonded SiC ceramics were prepared by reactive sintering in graphite bed. Ti–Si–Fe alloys could react with CO/N 2 at a low temperature (1200 °C), and the addition of Ti–Si–Fe alloys could reduce the nitriding temperature of Si. Density functional theory calculations suggested that Ti–Si–Fe alloys enhanced reaction activity via weakening the strength of C O and N N bonds. The regional equilibrium phase diagrams of Si–C–N–O and Ti–Si–C–N–O under CO/N 2 atmosphere were calculated by thermodynamics. The change of whiskers morphology was observed by scanning electron microscope. Furthermore, the bulk density, the cold modulus of rupture, and the cold compressive strength improved with Ti–Si–Fe alloys content. The results showed that the addition of Ti–Si–Fe alloys not only significantly promoted nitriding of Si and formation of Si 3 N 4 whiskers, but also improved the mechanical properties of the samples.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Kezhuo Li,Jin Luo,Longhao Dong,Gaoqian Yuan,Wen Lei,Quanli Jia,Haijun Zhang,Shaowei Zhang
Porous ceramics have attracted extensive attention because of their high porosity, low thermal conductivity , large specific surface area and good corrosion resistance . In this work, TiN porous ceramics with high porosity are successfully prepared via the combination of freeze-drying and in-situ nitridation reaction method using Ti powder and chitosan as raw materials. The influence of the solid content of Ti powder, the concentration of chitosan/acetic acid solution and the nitridation temperature on the morphologies and physical properties of as-prepared TiN porous ceramics are fully investigated. The sample with high porosity of 92.8% and low bulk density of 0.27 g/cm 3 can be obtained through optimal parameters (the solid content of Ti powder is 9.6 wt%, the concentration of chitosan/acetic acid solution is 5 wt%, and the nitridation temperature is 1473 K). Particular emphasize is that the as-prepared TiN porous ceramics can be used as sulfur host material for lithium-sulfur batteries (LSBs). Good rate performance and cycle stability of TiN/S electrodes are achieved by electrochemical performance tests. The initial discharge capacity of TiN/S electrodes is 778 mAh g −1 at 0.5C, and the capacity retention rate is 94% after 200 cycles.
研究领域:
材料科学
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电化学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Guangchao Xing,Chengji Deng,Jun Ding,Hongxi Zhu,Chao Yu
AlN-SiC porous composite ceramics were fabricated by heat-treating Al 4 SiC 4 porous ceramic green body prepared using the foaming method under flowing nitrogen. The porous structure could provide increased nitrogen diffusion channels, leading to a decrease in N 2 diffusion resistance and an increasing degree of nitridation. The micro-morphology of AlN was in the form of particles or whiskers and influenced by heating temperature and time parameters. AlN has good dispersibility with SiC particles, resulting in local homogeneous chemical composition of prepared AlN-SiC composite ceramics. Furthermore, the potential reaction mechanism responsible for the synthesis of AlN-SiC porous composite ceramics during the nitridation was revealed. This simple approach may be used for large-scale synthesis of AlN-SiC porous composite ceramics.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
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
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
·
染料化学
·
过程强化
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产品关联
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2020
·
IF 3.562
Yongxiang Zheng,Chengji Deng,Jun Ding,Hongxi Zhu,Chao Yu
An innovative approach was developed for the fabrication of AlN-Al 2 O 3 porous ceramic by heat-treating Al 4 O 4 C porous ceramic under a flowing nitrogen atmosphere. The effects of sintering temperature on phase and microstructural evolution changes were investigated. The results indicated that phase evolution of the nitridation of Al 4 O 4 C porous ceramics was significantly different from dense Al 4 O 4 C ceramics. AlN-Al 2 O 3 porous ceramic produced using this new method had a homogeneous local chemical composition with the two phases tightly combined in the composite material. Possible reaction mechanisms for the fabrication of AlN-Al 2 O 3 porous ceramic are discussed by considering reactions at the initial and later stages during the nitridation process.
研究领域:
材料科学
·
陶瓷工程
✓ 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
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产品关联
DOI
高影响因子
Biosensors-Basel
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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
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环境科学
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产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2012
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IF 2.769
Bo Jin,Juan Shen,Rufang Peng,Yuanjie Shu,Bisheng Tan,Shijin Chu,Haishan Dong
A new energetic polymer, polyvinyl acetate azide (PVAA), was synthesized via a two-step process involving initial chloroacetylation and subsequent azidation of poly(vinyl alcohol) and was characterized by elemental analysis , UV–Vis, ATR–FTIR, 1 H and 13 C NMR techniques. The glass-transition temperature of PVAA was evaluated by DSC method and the thermal stability of PVAA was tested by DTA and TGA methods. The results indicate that PVAA shows single glass-transition temperature at 24.60 °C and exhibits good resistance to thermal decomposition up to 200 °C. Moreover, the sensitivity properties of PVAA were measured with the national military standard methods and the compatibilities of PVAA with the energetic components of TNT-based melt cast explosives were studied by using the non-isothermal DSC method. The results indicate that PVAA is an insensitive energetic polymer and can be safely used in melt cast explosives.
研究领域:
材料科学
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化学工程
✓ 已验证
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
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Qiang Zhi,Bo Wang,Shan Zhao,Zhao Zhang,Yu-Chen Deng,Bao-Qiang Hou,Nan-Long Zhang,Jian-Feng Yang
Si 3 N 4 ceramic with ultrafine fibrous grains are expected to exhibit remarkable mechanical properties . In this work, highly porous Si 3 N 4 ceramic monoliths composed of ultrafine fibrous grains were developed via a novel vapor-solid carbothermal reduction nitridation (V-S CRN) reaction between SiO vapor and green bodies comprised of carbon nanotubes (CNTs), α-Si 3 N 4 diluents and Y 2 O 3 in a N 2 atmosphere. The unique fibrous grains-interconnected structure was developed through in-situ formation of Si 3 N 4 and following liquid phase sintering . The porous Si 3 N 4 monoliths with porosity of 61–78% was developed by controlling the contents of α-Si 3 N 4 diluents and densities of the CNT green bodies. With increasing of the α-Si 3 N 4 contents, Si 3 N 4 fibrous grains with an aspect ratio of approximate or higher than 20 could be achieved, and the grains were gradually refined. For the samples with 40 wt% α-Si 3 N 4 , the minimum mean grain diameter and pore size of 164 nm and 0.79 μm were achieved, respectively, and the resultant porous Si 3 N 4 monolith exhibited a flexural strength of as high as 73–102 MPa with the porosity of 61–73%, which is much higher than that of the reported in literature. The improvement of mechanical strength could be attributed to the densely interconnected bird's nests structure formed by the ultrafine fibrous grains. The effects of the α-Si 3 N 4 diluents on the resulting porous Si 3 N 4 monolith via this method were analyzed.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Wenhui Li,Yingxin Chen,Xin Li,Yi Zhong,Pei Xu,Yuanjie Teng
Synthetic antioxidants serve as essential protectors against oxidation and deterioration of edible oils, however, prudent evaluation is necessary regarding potential health risks associated with excessive intake. The direct adsorption of antioxidants onto conventional surface-enhanced Raman scattering (SERS) substrates is challenging due to the presence of phenolic hydroxyl groups in their molecular structures, resulting in weak Raman scattering signals and rendering direct SERS detection difficult. In this study, a diazo derivatization reaction was employed to enhance SERS signals by converting antioxidant molecules into azo derivatives, enabling the amplification of the weak Raman scattering signals through the strong vibrational modes induced by the N = N double bond. The resulting diazo derivatives were characterized using UV–visible absorption and infrared spectroscopy, confirming the occurrence of diazo derivatization of the antioxidants. The proposed method successfully achieved the rapid detection of three commonly used synthetic antioxidants, namely butylated hydroxyanisole (BHA), tert -butylhydroquinone (TBHQ), and propyl gallate (PG) on interfacial self-assembled gold nanoparticles. Furthermore, rapid predictions of BHA, PG, and TBHQ within the concentration range of 1 × 10 −6 to 2 × 10 −3 mol/L were achieved by integrating a convolutional neural network model. The predictive range of this model surpassed the traditional quantitative method of manually selecting characteristic peaks, with linear coefficients (R 2 ) of 0.9992, 0.9997, and 0.9997, respectively. The recovery of antioxidants in real soybean oil samples ranged from 73.0 % to 126.4 %. Based on diazo derivatization, the proposed SERS method eliminates the need for complex substrates and enables the analysis and determination of synthetic antioxidants in edible oils within 20 min, providing a convenient analytical approach for quality control in the food industry.
研究领域:
分析化学
·
食品科学
·
生物医学工程
✓ 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）