Arabian Journal of Chemistry
·
2023
·
IF 6
Bocong Li,Guoqiang Xiang,Gao Huang,Xiuming Jiang,Lijun He
A rapid, green synthesis strategy assisted by a self-exothermic reaction was designed to prepare highly luminescent carbon dots (CDs) from Ganpu tea infusion (G-CDs) within 5 min using H 2 O 2 and diethylenetriamine (DETA) as the exothermic reactants. G-CDs were successfully obtained through a self-exothermic reaction The prepared G-CDs exhibited clear excitation-dependent characteristics and displayed a strong ultraviolet fluorescence emission (385 nm) at the excitation wavelength of 320 nm. The fluorescence of G-CDs was quantitatively quenched by para -nitrophenol (p-NP) with a concentration range of 0.05–50 µM through inner filter effect (IFE). Since p-NP is one of the hydrolysates of the substrate pNPG under the action of Beta-glucosidase (β-Glu), a new fluorescence assay was developed for the indirect determination of β-Glu activity. The detection limits of G-CDs based fluorescence assays are 14.6 nM for p-NP and 0.074 U·L -1 for β-Glu activity, respectively. The developed fluorescence assays were successfully applied to the detection of p-NP in water and human urine samples and β-Glu activity in fruit samples with satisfactory results.
研究领域:
分析化学
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生物化学
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DOI
高影响因子
Journal of Applied Biomaterials & Functional Materials
·
2020
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IF 2
Xue Xia,Rui Shi,Jinhui Huang,Yubao Li,Yi Zuo,Jidong Li
The aim of the current study is to alleviate the adverse effect of the strongly exothermic polymerization of polymethyl methacrylate (PMMA) bone cement in clinical applications. In this study, paraffin/poly(methyl methacrylate–methylene bisacrylamide) (paraffin/P(MMA-MBA)) phase change microcapsules (MPn; n = 1, 2) were developed via the emulsion polymerization method. The reduction of the maximum temperature of polymerization (Tmax) and physicochemical properties were evaluated after doping commercial PMMA cement with MPn in specific proportions (10%, 20%, and 30%). The results reveal that the MPn-doped PMMA exhibited an effective reduction in Tmax, which can help alleviate the adverse effect of the strong exothermic reactions during PMMA setting. After doping with the MPn, the mechanical properties of the PMMA cement decrease and the values are close to that of body cancellous bone. The Tmax of the cement doped with 20 wt% MP1 is 37.6°C, which is close to body temperature. Significantly, the setting and compressive properties of the optimized group can still adhere to clinical requirements. The MPn doping PMMA technique holds much promise in clinical practice.
研究领域:
材料科学
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生物医学工程
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DOI
PubMed
高影响因子
LUMINESCENCE
·
2021
·Vol. 37
·期 1
·118-126
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IF 2.464
Ke Su,Guoqiang Xiang,Xinrong Jin,Xin Wang,Xiuming Jiang,Lijun He,Wenjie Zhao,Yaming Sun,Chen Cui
Locust powder was converted into water-soluble fluorescent nitrogen-doped carbon dots (N-CDs) with gram-scale yield through a self-exothermic reaction between nitric acid and diethylenetriamine (DETA) within 10 min. The morphology, elemental information, and optical properties of the N-CDs were characterized using high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared, ultraviolet–visible and fluorescence spectroscopy. Spectroscopic investigation indicated that the fluorescence emission behaviour of N-CDs is excitation wavelength dependent, with the strongest emission peak at 470 nm using a 390 nm excitation wavelength. The strong absorption peak of sunset yellow (SY) at 482 nm overlaps substantially with the blue emission peak (470 nm) of N-CDs. This enables the fluorescence emission of N-CDs to be obviously quenched by SY through the inner filter effect. There was a good linear relationship between the fluorescence quenching degree and the concentrations of SY within the range 0.5–40 μM. The detection limit of developed fluorescence assay for SY is 28 nM, and the relative standard deviation is 2.3% (c = 10 μM). The N-CDs derived from locusts by the self-exothermic reaction are highly selective and sensitive fluorescent probes for SY, which were applied to the fluorescence sensing of SY in different food samples with satisfactory results.
研究领域:
材料科学
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分析化学
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食品科学
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DOI
PubMed
高影响因子
FUEL
·
2019
·
IF 5.128
Min Zhong,Yuanyuan Guo,Jungang Wang,Congbiao Chen,Zhancheng Ma,Litao Jia,Bo Hou,Debao Li
The development of alternative to silicon carbide (SiC) holds great promise in energy and environmental related catalysis because the harsh preparation process and high cost limit its large-scale application. In this work, the core-shell structured ZnAl 2 O 4 @Al ceramic-metal composites (Zn-Al-T) are prepared from low cost metallic Al powder by a facile and environment-friendly approach to replace silicon carbide for Co-based Fischer-Tropsch synthesis (FTS, a typical strong exothermic heterogeneous catalytic reaction). The composition, thermal conductivity, surface chemical properties and pore configuration of the ZnAl 2 O 4 @Al composites can be easily modulated by controlling the calcination condition. Among Zn-Al-T composites, the Zn-Al-650 and Zn-Al-750 samples demonstrate optimum coupling of physicochemical properties, i.e., robust chemical stability, meso -macropore structure (wide mesopore and high macroporosity) and high thermal conductivity. Thus, the excellent FT performance (low CH 4 selectivity and high selectivity to C 5+ ) was obtained on the Co/Zn-Al-650 and Co/Zn-Al-750 catalysts. The heat transfer experiments were conducted on a special tubular fixed-bed reactor (I.D. = 22 mm) under near-industrial conditions. At similar reaction rates, the effective radial thermal conductivity coefficient (k eaff ) in the Co/Zn-Al-650 catalyst bed is 3–4 times and 1–2 times that in the Co/Al 2 O 3 and Co/SiC catalyst beds respectively, resulting in a more uniform temperature distribution in Co/Zn-Al-650 catalyst bed. In addition, the ZnAl 2 O 4 @Al composite has wide application prospect in strong exothermic/endothermic catalytic system owing to its high thermal conductivity, adjustable physico-chemical properties, facile preparation method and low cost.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2025
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IF 7.7
Xiaotong Li,Yisong Wang,Jiamai Ren,Zeliu Li,Fenglin Zhang,Xinpu Zhang,Wei Peng
Infrared (IR) thermal imaging offers a reliable technique in the field of gas detection, it can convert the invisible IR radiation into a visible IR image based on the temperature difference between the target and the background or the parts of the target, and its gas selectivity mainly depends on the spectral absorption properties of the target gas in IR spectrum . Unfortunately, owing to weak absorption in the IR region , the precise selective detection of hydrogen can therefore be quite challenging by using traditional IR detection methods. To address the limitations of IR thermal imaging technology in hydrogen detection and enhance its hydrogen selectivity, a novel catalytic IR thermal imaging-based hydrogen monitoring platform is proposed and demonstrated. To achieve specific hydrogen selection, a hydrogen-sensitive highly-exothermic mesoporous material , Pt-WO 3 , is designed and prepared, which can be used as highly-active catalysts to specifically activate exothermic reaction between hydrogen and oxygen at room temperature, and a common IR camera can become a hydrogen-selective gas detection device by adding a Pt-WO 3 -based window plate, the IR radiation changes on Pt-WO 3 -based window plate surface caused by exothermic reaction can be rapidly and accurately recognized by using IR camera. Additionally, real-time image processing can be used to create high-resolution IR images from original low-resolution IR images and can promote to further improve the detection accuracy. Through analyzing the performance, it can be concluded that the hydrogen detection platform assembled with a higher Pt-WO 3 mass or density window plate is more sensitive to hydrogen. When the hydrogen concentration rises to 1.6 % and a 2.0 mg and 3 mm coating diameter Pt-WO 3 -coated window plate is selected as a hydrogen selective element, the maximum surface temperature of the hydrogen selective window plate reaches 100.76℃ (which contains the ambient background temperature component), however, this is accompanied by a longer response and recovery time. While a 0.5 mg and 4 mm coating diameter Pt-WO 3 -coated window plate is selected as a hydrogen selective element, and hydrogen concentration is 0.5 %, the response and recovery time of this catalytic IR hydrogen detection system is 17 s and 24 s at room temperature. Experimental results indicate that this catalytic IR thermal imaging-based hydrogen detection scheme has the potential to offer a novel solution in the field of gas monitoring.
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高影响因子
Inorganic Chemistry Frontiers
·
2021
·Vol. 8
·期 7
·1747-1761
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IF 6.569
Keding Li,Yuqing Lei,Jun Liao,Yong Zhang
MXene-supported CuO nanocomposites (MCNs) were synthesized through an ice-crystal templating method without using any chemical modifiers. Nano-sized CuO particles were uniformly and stably attached to the surface of MXene nanosheets. The catalysis of the MCNs in ammonium perchlorate (AP) decomposition was studied and the results indicated that the MCNs as catalysts (2 wt%) could significantly decrease the high temperature decomposition (HTD) temperature of AP from 425.0 °C (pure AP) to 324.9 °C (AP with MCNs-3) and increase the exothermic heat from 295.2 J g−1 (pure AP) to 1272.9 J g−1 (AP with MCNs-3). With the increase of the mass ratio, the decomposition temperature decreased at first and then increased. When the ratio of MCNs-3 was 4 wt%, the HTD temperature of AP was reduced by as much as 114.4 °C and the exothermic heat was remarkably increased to 1360.6 J g−1. The high catalytic activity of MCNs-3 for AP thermal decomposition might be owing to the synergistic effect between MXene nanosheets and CuO nanoparticles. In other words, the results proved that the MXene in combination with CuO could be an effective way to enhance the catalytic performance of CuO in AP decomposition, which has potential application value in AP-based composite solid propellants.
研究领域:
材料科学
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化学工程
·
推进剂技术
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2019
·Vol. 93
·期 1
·111-122
·
IF 1.986
Wang Yinfeng,Li Zhi,Huber Lukas,Wu Xiaoxu,Huang Siqi,Zhang Yan,Huang Rui,Liu Qiong
Reducing organic groups on hydrophobic silica aerogels (SA) is worth exploring for lowering their thermal hazard risk. In this work, we used dimethyldichlorosilane (DMDCS) to modify silica alcogels, investigated the effects of DMDCS concentration and focused on the thermal hazard assessment of the DMDCS modified SA (DSA). It was turned out that the DSA had less −CH 3 content in spite of the thermal stability close to the trimethylchlorosilane modified SA (TSA), about 240 °C. The kinetics study suggested the apparent activation energy ( E a ) could be divided into two segments, corresponding to the two processes in the pyrolysis. The positive enthalpy and entropy changes indicated that the thermal oxidation of the DSA was an exothermic reaction, which could not occur without external energy supply. The average E a of the DSA was far larger than that of the TSA and the gross calorific value of the DSA decreased by about 12% compared with that of the TSA. All these results drew a conclusion that the DMDCS modified SA reduced the thermal hazard to some degree, which provided one possible solution to further lower the thermal hazard of hydrophobic SA.
研究领域:
材料科学
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化学工程
·
热物理
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Feixiang Bian,Jiage Yu,Wenlong Song,Hui Huang,Chu Liang,Yongping Gan,Yang Xia,Jun Zhang,Xinping He,Wenkui Zhang
Si/graphene composites have attracted great attention for application as anode materials of Li-ion batteries owing to their superior capacity and cycle stability. Magnesiothermic reduction of silica is a quite scalable and cost-effective method to synthesize Si/graphene composite. However, this remains a considerable challenge because the intense heat accumulation during the violent exothermic reaction makes it difficult to remain the desired nanostructure of the silica precursor and results in severe aggregation of silicon grains. Herein, we offer a mild and scalable route to efficiently convert silica into morphology-controlled Si nanoparticles by magnesium hydride (MgH 2 ) reduction at a low temperature. The Si nanoparticles that are produced from silica template structure are fine and narrowly distributed, showing the ability to preserve morphology characteristics. The as-synthesized Si/rGO composite exhibits outstanding electrochemical properties , delivering a superior rate capability (513 mA h g −1 at 5 A g −1 ) and a high reversible capacity of 894 mA h g −1 over 100 cycles at 0.2 A g −1 . We believe MgH 2 reduction of silica demonstrates its great potential in fabricating Si based anode materials.
研究领域:
材料科学
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纳米技术
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电化学
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能源存储
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无机合成
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锂离子电池
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纳米材料
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Lijia Qiu,Xufang Zong,Rongfang Yuan,Beihai Zhou,Huilun Chen,Jia Zhang
In this study, graphene-like biochar (IZBC) was prepared by pyrolysis of wheat straw in the presence of catalyst and activator. The formation of graphene in IZBC could be divided into three stages: shell core generation, carburization, and carbon precipitation. When the pyrolysis temperatures were in the ranges of 500–600 ℃, 600–700 ℃, 700–800 ℃ and 800–900 ℃, 17%, 32%, 13% and 38% of graphene were produced, respectively. The contribution ratios of graphene by FeCl 3 , ZnCl 2 and HCl were 64%, 23% and 13%, respectively. Moreover, IZBC was filled with porous wavy three-dimensional graphene nanosheets that enabled self-aggregation to be effectively prevented, which was superior to the striped two-dimensional structure. The adsorption of IZBC for dimethoate was a spontaneous exothermic reaction with the adsorption capacity of 980 μmol/g, which was consistent with the pseudo-second-order and intraparticle diffusion models. The adsorption was inhibited by coexisting cations, anions, and humic acid in water. Dimethoate was adsorbed on graphene through embedded separation, with pore filling, cation- π and electrostatic attraction as the key driving forces. In addition, the adsorbed saturated IZBC could be effectively regenerated for many times by 2 mol/L HCl solution.
研究领域:
环境科学
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材料科学
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化学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2023
·
IF 3.8
Jinpei Huang,Xingwei Lu,Xuejing Zhang,Yiqiang Jin,Yifeng Zhou
1-Oxa-2-azaspiro [2.5] octane, as one of N-H oxaziridines , is a selective electrophilic aminating agent for N-, S-, C-, and O-nucleophiles. It has the features of stereoselectivity and the absence of formation of strongly acidic or basic byproducts, leading to considerable interest in the development of organic synthetic methods. Currently, the economically feasible route of production of 1-oxa-2-azaspiro [2.5] octane is the reaction of cyclohexanone with ammonia and sodium hypochlorite. However, due to strong exothermic reactions, massive gas release and heterogeneous reaction, the controllability, efficiency and safety of the reaction are in great difficulty using batch technology. In this paper, a microreaction system containing predispersion, reaction and phase separation was introduced into the preparation of 1-oxa-2-azaspiro [2.5] octane. The research results showed that precise control of the process including droplet dispersion, temperature control, reaction time control and fast continuous phase separation, was the key to process intensification. Under optimal conditions, the concentration of 1-oxa-2-azaspiro [2.5] octane in product obtained by microreaciton system (∼2.0 mol·L −1 ) was much higher than that obtained by batch technology (0.2–0.4 mol·L −1 ), which demonstrated that the continuous-flow synthesis would be a more efficient substitute for batch synthesis. Meanwhile, the results of the derivation experiments also showed that the aminating agent solution with higher concentration was more advantageous in the applications.
研究领域:
有机化学
·
化学工程
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合成化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）