SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Wenxuan Li,Peifeng Li,Feiqiang He,Xiaoping Zhang,Yuling Zhu,Jianhua Ding
In this study, a foam fractionation technique was developed for the separation and enrichment of the trace m-phenylenediamine (MPD) and o-phenylenediamine (OPD) in solution. Firstly, a self-designed foam fractionation device was assembled and built, followed by a comprehensive characterization on gas types, foam fractionation column parameters, and porous sieve plate material used in the apparatus. Subsequently, the most crucial parameters for the separation and enrichment, such as surfactant species, solution pH, electrolyte categories, and gas flow rate, were identified and optimized. The mechanisms of key processes during foam fractionation under the influence of these parameters were thoroughly discussed. Other influencing factors, such as surfactant concentration, foam collection time, and solution volume in the fractionation column, were optimized using response surface methodology (RSM). Under these optimal conditions, maximal enrichment ratios of 138.2 and 85.5 were achieved for MPD and OPD, respectively. Finally, foam fractionation coupled with high-performance liquid chromatography (HPLC) was employed to detect MPD and OPD in the solution. The results demonstrated limits of detection (LOD) of 1.5 × 10 −2 μg/L and 1.5 μg/L for MPD and OPD, with relative standard deviation (RSD) values of 4.1 % and 3.9 %. When testing various actual samples, the recoveries were in the range from 92.0 % or greater in all cases. The method exhibited advantages of high sensitivity, precision, and accuracy, attributed to the high enrichment efficiency of foam fractionation. In conclusion, the foam fractionation method established in this study offers simplicity in apparatus, operational convenience, environmental friendliness (minimized use of organic solvents), and high enrichment efficiency. It proves valuable for the quantitative analysis of trace amounts of MPD and OPD in solution, presenting a novel approach for the detection of trace organic compounds in solutions.
研究领域:
分析化学
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环境科学
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DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 28
·16515-16525
·
IF 3.119
Junya Cao,Fenggang Han,Liguo Wang,Xiaoyu Huang,Yan Cao,Peng He,Huanhuan Yang,Jiaqiang Chen,Huiquan Li
A series of Ru/g-C3N4 materials with highly dispersed Ru were firstly prepared by an ultrasonic impregnation method using carbon nitride as a support. The catalysts were characterized by various techniques including BET and elemental analysis, ICP-AES, XPS, XRD, CO2-TPD and TEM. The results demonstrated that Ru/g-C3N4 materials with a mesoporous structure and highly dispersed Ru were successfully prepared. The chemo-selective hydrogenation of p-phenylenediamine (PPDA) to 1,4-cyclohexanediamine (CHDA) over Ru/g-C3N4 as a model reaction was investigated in detail. PPDA conversion of 100% with a CHDA selectivity of more than 86% could be achieved under mild conditions. It can be inferred that the carbon nitride support possessed abundant basic sites and the Ru/g-C3N4-T catalysts provided suitable basicity for the aromatic ring hydrogenation. Compared to the N-free Ru/C catalyst, the involvement of nitrogen species in Ru/g-C3N4 remarkably improved the catalytic performance. In addition, the recyclability of the catalyst demonstrated that the aggregation of Ru nanoparticles was responsible for the decrease of the catalytic activity. Furthermore, this strategy also could be expanded to the selective hydrogenation of other aromatic diamines to alicyclic diamines.
研究领域:
催化
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化学工程
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材料科学
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DOI
PubMed
高影响因子
Advanced Optical Materials
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2024
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IF 8
Xipeng Dong,Wanqing Li,Xue Chen,Er Zhuo,Zizhuo Zhai,Hongxia Qi,Yu Kang,Pudun Zhang
O -phenylenediamine (OPD) is commonly used as a precursor in the preparation of red emissive carbon quantum dots (R-CQDs) due to the sp 2 hybridized structure. However, the low fluorescence quantum yield (QY) of the OPD-based R-CQDs limits its application. Although some efforts have been made, the improvement of QY is still limited. In this paper, a strategy is proposed to improve the QY of OPD-based R-CQDs by introducing ethylenediamine (EDA), which plays a key role as a nitrogen (N) dopant due to its high N content. The molar ratio of OPD to EDA (M OPD /M EDA ), the reaction time (t) and temperature (T), and the amount of concentrated H 2 SO 4 (V H2SO4 ), are optimized. The R-CQDs with QY as high as 32.65% and full width at half maximum (FWHM) emission as narrow as 25 nm are obtained via a hydrothermal procedure under the optimal experimental conditions (i.e., M OPD /M EDA = 1/3, t = 6 h, T = 180 °C and V H2SO4 = 4 mL). Such a QY is higher than most of the reported OPD-based R-CQDs. Besides, it is found that concentrated H 2 SO 4 acts as the catalyst in addition to protonation. The enhancement of QY is attributed to the increase of the aromatic N-containing heterocyclic structures (C═N) after the introduction of EDA and catalysis by H 2 SO 4 .
研究领域:
材料科学
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化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
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IF 8.2
Minghan Wu,Siqi Hao,Linfeng Qi,Yu Shi,Wei Yang,Jingjing Bao,Min Du,Zhengyu Mo,Licheng Sun
Thermogalvanic cells (TGCs) are at the forefront of effective thermoelectric conversion methods, but the practical utilization of their integrated devices is hindered by the suboptimal performance of N-type TGCs. Herein, a novel redox couple of Cu/Cu(en)22+ is proposed to construct a liquid-state N-type TGC. The electrochemical reaction involving the Cu electrode, ethylenediamine (en), and their chelated compound Cu(en)22+ exhibits a significant reaction entropy change, resulting in an enhanced temperature coefficient (α). We reveal that the α of the Cu/Cu(en)22+-based TGC reaches 1.64 mV K–1. Furthermore, by optimizing the concentrations of Cu2+, ethylenediamine, and (NH4)2SO4 in the electrolyte, both α and normalized power density can be significantly improved, achieving values of 2.12 mV K–1 and 676 μW m–2 K–2, respectively. Moreover, by constructing a P–N junction with P-type and N-type TGC, we achieve a high potential of 121 mV under a temperature gradient of 35 K. This work expands the available redox couple options for N-type TGCs and offers a new pathway for efficient thermoelectric conversion.
研究领域:
材料科学
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能源技术
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Qilin Xu,Huachun Fan,Hongmiao Yao,Duoheng Wang,Hangwei Yu,Bingbing Chen,Zhiqun Yu,Weike Su
Monoacylated symmetrical diamines are building blocks or intermediates of several well-established drugs. However, for the symmetrical diamines, the two amine groups located in a similar chemical environment make the selective monoacylation rather difficult and no kinetics study has ever been reported before. To comprehend this kind of reaction more deeply, a continuous flow microfluidic system was developed to evaluate the reaction kinetics of m -phenylenediamine and benzoic anhydride. At first, the reaction order of each reactant, pre-exponential factors and activation energies were determined in turn. The possible reaction mechanism was postulated from the reaction order. Then, a series of validation experiments were designed to show the accuracy and the applied range (concentration and temperature) of the kinetic model. Next, to obtain a controlled selectivity, the effects of initial concentration, reaction temperature and molar ratio on the selectivity were investigated through the model simulation. In the end, under the conditions optimized by the kinetic model, 96.9% selectivity and 92.5% yield were obtained in the microreactor.
研究领域:
有机化学
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药物化学
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化学工程
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DOI
高影响因子
COMPOSITE INTERFACES
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2019
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IF 2.025
Guiming Qi,Kun Qiao,Tingting Wang,Li Wang
Interfacial strength between fiber and matrix is an important factor affecting the mechanical properties of carbon fiber composites. Different daimines, ethylenediamine (EDA) and p-phenylenediamine (PPD), were grafted on carbon fiber to enhance interfacial strength of composites. Functional groups and chemical composition were tested by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Thermaogravimetric analysis and Roman spectroscopy. Scanning electron microscope was used to characterized surface morphology. Results revealed that EDA with flexible structure was more easily grafted onto surface. In contrast, PPD with rigid structure could improve the interfacial performance better. More importantly, carbon fiber grafted on both EDA and PPD had the highest wettability and interlaminar shear strength owing to the presence of sufficient functional groups on carbon fiber surface. Compared with untreated carbon fibers, the surface energy and the interlaminar shear strength of the grafted EDA and PPD carbon fibers increased by 38.57% (50.98 mN/m) and 44.81% (69.8 MPa) respectively. The investigation provides an approach to enhance the mechanical properties of fiber composites by controlling the structure of grafted components.
研究领域:
材料科学
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复合材料工程
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DOI
高影响因子
POLYMER SCIENCE SERIES B
·
2021
·Vol. 63
·期 3
·239-244
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IF 1.049
Huanhuan Zhu,Niu Mingkang,Feng Zhongtai,Li Chengjie,Li Yonghao,Jiao Qingze,Wang Shanshan,Feng Caihong,Zhao Yun,Lv Yuzhen
Abstract To obtain aromatic polyamides with reduced dielectric constant, a series of aromatic polyamide copolymers derived from the reaction between m -phenylenediamine to trans -1,2-cyclohexanediamine and isophthaloyl chloride were synthesized using the low-temperature solution polymerization in the presence of 2-methylpyridine. The influence of the content of trans -1,2-cyclohexanediamine on the structure and properties of aromatic copolyamides was evaluated. With increasing the content of trans -1,2-cyclohexanediamine, the inherent viscosities of copolymers decrease from 1.95 to 1.14 dL/g. The copolymer with 25 mol % of trans -1,2-cyclohexanediamine has a reduced dielectric constant ε r of 4.61 at 1 MHz, which is 26% lower than homopolyamide. Meanwhile, as-synthesized aromatic polyamides and copolyamides show good thermal stability and mechanical properties.
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
Minerals
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2018
·Vol. 8
·期 4
·149
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IF 1.835
Weiqing Wang,Jinyao Cong,Jie Deng,Xiaoqing Weng,Yiming Lin,Yang Huang,Tiefeng Peng
The effect of hydrofluoric acid (HF) pretreatment on flotation of feldspar and quartz using dodecylamine (DDA) as collector was investigated by micro-flotation, zeta potential, pyrene fluorescence spectroscopy, attenuated total reflection flourier transformed infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and bench scale flotation. The micro-flotation tests revealed that there was little difference in the flotation of feldspar and quartz at pH 2, using H2SO4as pH regulator. After HF pretreatment, the floatability of feldspar significantly increased while the floatability of quartz showed no change. HF pretreatment resulted in leaching of SiO2and enrichment of Na, K and Al on the feldspar surface. Consequently, the negative surface charge of feldspar increased at pH 2, which allowed for the flotation separation of the feasible minerals. This took place via an increased electrostatic adsorption between DDA and Na, K, Al on the feldspar surface, which effectively increased its hydrophobicity and as a result, improved the floatability of feldspar. An alternative process which exhibited effective separation of quartz and feldspar while recycling the tailwater from the flotation was proposed.Keywords:hydrofluoric acid;flotation;DDA;ATR-FTIR
研究领域:
矿物加工工程
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材料科学与工程
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DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2021
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IF 3.498
Zhi-Juan Zhang,Peng-Wei Li,Lu-Ping Liu,Li-Hua Ru,Han-Xiao Tang,Wei-Sheng Feng
The analysis of breath VOC biomarkers is an efficient method for the early diagnosis of lung cancer. In this work, the zirconium UiO-66 was post-synthetically modified by using methylamine (MA), ethylenediamine (ED) and N,N′ -dimethylethylenediamine (MMEN), respectively. The modified UiO-66 materials were thoroughly characterized, including PXRD , FTIR, TGA , physical adsorption at 77 K by nitrogen and photoluminescence analysis. The sensing properties of the modified UiO-66 materials toward the selected five potential breath VOC biomarkers were investigated. Results showed that after modification, the BET surface area and total pore volume all decreased, and followed the order: UiO-66 > UiO-66-MA > UiO-66-MMEN > UiO-66-ED. Furthermore, the N–H group was successfully grafted into the modified UiO-66 samples. In comparison with UiO-66, the fluorescence intensities of UiO-66-MA, UiO-66-ED and UiO-66-MMEN toward hexanal , styrene and isoprene all obviously increased, while the fluorescence intensities of the modified UiO-66 materials toward 1-propanol and ethylbenzene all decreased a lot, accompanied by the frequency shift. In addition, the LOD of hexanal on UiO-66-MA was calculated to be as low as 12 ppm, which was obviously lower than that of UiO-66 (31 ppm). The fluorescence quenching of hexanal was mainly due to the FRET mechanism. The results of this study would provide information for the development of early breath diagnosis of lung cancer.
研究领域:
医学
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材料科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2023
·Vol. 11
·期 12
·2770-2777
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IF 7
Shanhao Hao,Cheng Fu,Lin Zhou,Zhanghong Guo,Qijun Song
Iridium nanoparticles with an average size of 1.7 nm (Tar-IrNPs) were synthesized by the reduction of IrCl3 with NaBH4 in the presence of tartaric acid. As prepared Tar-IrNPs showed not only oxidase, peroxidase and catalase activities but also exhibited unprecedented laccase-like activity, which can catalyze the oxidation of the substrates o-phenylenediamine (OPD) and p-phenylenediamine (PPD) accompanied by significant color changes. The superb catalytic performance is evidenced by the fact that Tar-IrNPs can achieve better laccase-like activity with only 2.5% of the dosage of natural laccase. Furthermore, they also exhibited superior thermal stability and broader pH adaptability (2.0–11) over that of natural laccase. Tar-IrNPs can retain more than 60% of their initial activity at 90 °C, while the natural laccase has totally lost its activity at 70 °C. At a prolonged reaction time, the oxidation products of OPD and PPD can form precipitates due to oxidation induced polymerization. Thus Tar-IrNPs have been successfully used for the determination and degradation of PPD and OPD.
研究领域:
材料科学
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催化
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分析化学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
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2024
·Vol. 14
·期 49
·36273-36280
·
IF 3.9
Juan Hou,Qinqin Chen,Xiangzhi Meng,Huiling Liu,Wei Feng
Green fluorescent carbon dots (GCDs) were synthesized using o-phenylenediamine and ethylenediamine through a one-step hydrothermal method, thereby eliminating the need for further processing. The GCDs exhibited strong green fluorescence that was effectively quenched by Hg2+ and Fe3+, with minimal interference from other metal ions, anions, and small biological molecules. By optimizing the buffer solution, interference from Fe3+ was mitigated, which enhanced the robustness of the GCDs as a fluorescence probe for Hg2+ detection. The detection range for Hg2+ was 0–100 μM, with a detection limit of 300 nM. The quenching mechanism was thoroughly investigated, and the GCDs were successfully applied to detect Hg2+ in real water samples, yielding satisfactory results. This work highlights the potential of GCDs for practical environmental monitoring and water quality analysis.
研究领域:
材料科学
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环境科学
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分析化学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Meiqing Chen,Pingxiao Wu,Yajie Zhu,Shanshan Yang,Yonghong Lu,Zhang Lin
In order to enhance the visible light-driven photocatalytic H 2 production activity of CdZnS, an ethylenediamine-assisted hydrothermal pathway was used to synthesize CdxZn1-xS(en) with different Cd/Zn molar ratios . It was found out that the prepared Cd 0.5 Zn 0.5 S(en) possessed the highest photocatalytic H 2 production rate of 13539.0 μmol h −1 g −1 that was higher than that of CdZnS. The key to this achievement could be ascribed to the stacking faults formation, the optimum band gap with conduction band position and small crystallite size. Based on this, Cd 0.5 Zn 0.5 S(en) was modified by NiS for further improving the activity. The obtained Cd 0.5 Zn 0.5 S(en) NiS with NiS loading content of 0.25 wt% exhibited much higher photocatalytic H 2 production rate, reaching up to 38187.7 μmol h −1 g −1 that were among the highest efficiencies for semiconductor photocatalysts ever reported. It was confirmed that the nanosized NiS anchored on Cd 0.5 Zn 0.5 S(en) interface, acting as electron trapping sites, attributed to the spatial suppressions of electron-hole recombination. Meanwhile, the NiS loaded on the surface optimized the photogenerated electron transfer pathway between the semiconductor materials that gives rise to significantly enhanced photocatalytic activity . This study would put forward a facile method for developing high photocatalytic activity and low-cost catalytic material for H 2 production, which provide a new thought to address the global energy crisis and the environmental contamination.
研究领域:
材料科学
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能源化学
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环境科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）