FUEL
·
2021
·
IF 6.609
Ya-Qi Shan,Lin-Xin Yin,Oraléou Sangué Djandja,Zhi-Cong Wang,Pei-Gao Duan
Ru supported on activated carbon (C), Al 2 O 3 , CeO 2 , MgO, TiO 2 , and ZrO 2 were prepared and employed to boost supercritical water gasification (SCWG) of microalgae hydrothermal liquefaction (HTL) downstream water at 600 °C for 1 h. Effects of catalysts, water density, and Ru/C loading on total organic carbon (TOC) reduction, carbon gasification efficiency (CGE), and gas yield were examined. All the Ru catalysts showed a positive effect on TOC reduction and converted organics in the HTL downstream water to fuel gas, with H 2 and CH 4 as the two most abundant component. With the addition of Ru/C, almost complete removal of TOC, the highest CGE, and H 2 yield were achieved due to its largest metal dispersion. With the addition of Ru/C, increasing water density and catalyst loading favored TOC reduction and CGE increase as well as the total gas yield. The highest H 2 content of 50% and yield of 2.62 mmol/g (aq.) were obtained at the highest catalyst loading of 12.0 mg (Ru/C) /mL (aq.) . This study suggested that SCWG with the addition of Ru/C was a promising strategy to produce fuel gas rich in H 2 , from the organics in the microalgae HTL downstream water.
✓ 已验证
产品关联
DOI
高影响因子
SN Applied Sciences
·
2021
·Vol. 3
·期 3
·1-9
·
IF 0
Ma Yinzheng,Wen Yingying,Chen Jinping,Zhang Yunxia,Zhang Haiying,Sui Jinlei,Yi Guohui,He Xiaowen
A rapid and sensitive headspace gas chromatography-mass spectrometry (HS-GC–MS) method was established for the determination of benzyl isothiocyanate (BITC) in the peel, pulp, and seeds of Carica papaya Linn. Tween 80 solution with a concentration of 0.002% ( w/v ) was chosen as a headspace medium for solving the poor solubility of BITC in water without using organic solvents and ensuring high headspace efficiencies. Extraction parameters had been evaluated and optimized by using an orthogonal design with an OA 9 (3 4 ) table. Optimal headspace conditions were obtained when vials were equilibrated at 80 °C for 20 min at a stirring speed of 375 rpm. The calibration curve obtained by using GC–MS was linear in a concentration range of 10–320 ng/mL. The recoveries of peel, pulp, and seeds ranged from 97.3 to 100.6% with RSDs less than 3.0%. The method is simple, rapid, sensitive, and environmentally friendly. It is suitable for analyzing BITC in papaya fruit and is expected to have important application potential in the extraction of water-insoluble volatile components in foods, plants, medicines, and other samples.
✓ 已验证
产品关联
DOI
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 17
·7594-7601
·
IF 3.591
Yongrui He,Meiling Qi
This work presents a novel strategy for the construction of a capillary column with high resolving performance and inertness for gas chromatographic (GC) analysis by combining the proposed surface modification with a selective stationary phase. Through the modified biphasic sol–gel reaction inside a capillary GC column, porous modification was made on the capillary surface (PM capillary) prior to coating with a stationary phase. Herein, we designed and synthesized a new triptycene-based stationary phase (TPPG) for the study. Using the proposed strategy, the PM-TPPG column was fabricated with a column efficiency of 4950 plates per m determined by n-dodecane at 120 °C and then investigated for its separation performance, inertness, repeatability, loadability and thermal stability. As demonstrated, the PM-TPPG column showed distinct advantages in these aspects over two reference columns (TPPG column and commercial PEG column). Particularly, the PM-TPPG column well resolved all the components in the Grob mixture and exhibited distinctly improved peak shapes for carboxylic acids and heterocyclic bases. Moreover, it exhibited excellent repeatability and reproducibility and higher column loadability than the two reference columns. Its applications to purity monitoring of chemical products demonstrate its good potential for practical GC analysis.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Zixing Guo,Wenji Zheng,Xiaoming Yan,Yan Dai,Xuehua Ruan,Xiaochen Yang,Xiangcun Li,Ning Zhang,Gaohong He
Cage-type MOFs based Mixed-matrix membranes (MMMs) hardly exhibit screening effect of gas molecules due to the flexible aperture. Regulation of nanocages of MOFs by Ionic Liquid (IL) has been proved to be effective. Therefore, in this work, an IL adsorption/infiltration two-step strategy is proposed to confine IL into the nanocages of MOFs, achieving fine tuning of effective cage size for screening gas pair with similar size. [Bmim][PF 6 ] are first adsorbed on the outer-surface of ZIF-8, then through heat treatment, the aperture of ZIF-8 is dilated, and the bigger [Bmim][PF 6 ] molecules infiltrate through the dilated aperture into the nanocage driven by thermodynamics and differential concentration. When the temperature is down to room temperature, the aperture is narrowed to 3.4 Å, thus [Bmim][PF6] are confined into nanocages, which are confirmed by PXRD , TGA and FT-IR characteristics. By controlling IL content in the cage, the effective cage size of ZIF-8 is tuned to specific slope among dynamic diameters of CO 2 over N 2 , which is perfectly reflected in the CO 2 /N 2 separation. Compared with ZIF-8/Pebax MMMs, the IL@ZIF-8/Pebax MMMs exhibit improved CO 2 /N 2 selectivity but decreased CO 2 permeability, demonstrating effectiveness of cage size adjustment. Furthermore, with the IL molecules inside ZIF-8 cage increasing, the CO 2 /N 2 selectivity of the MMMs continues to rise, indicating cage size screening effect of ZIF-8 by IL infiltration . Especially, the IL 8 @ZIF-8/Pebax MMMs exhibit the best gas separation performances with CO 2 permeability of 117 Barrer and CO 2 /N 2 selectivity of 84.5, beyond the 2008 Robinson upper bound. The proposed strategy provides an effective but facile way to confine IL into the cages of MOFs to precisely screen gas pairs with similar size and can be easily expanded to other IL and MOFs system.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Chanchal Kumar Kundu,Xin Wang,Mohammad Ziaur Rahman,Lei Song,Yuan Hu
A DOPO-based phosphorus compound (DOPA) was synthesized and applied onto the pure and chitosan (CS) modified polyamide 66 (PA66) fabric surfaces via a simple pad-dry-cure method to improve the flame retardant properties of the same. The pure and chitosan modified fabric samples treated with DOPA at different content % degraded in a different way as the char residue formation and releasing of volatile and non-volatile gas species were dissimilar which were evident from the thermogravimatric and thermogravimetric-gas chromatography-mass spectroscopy (TG-GC-MS) test analysis. Obtained results also showed that no dripping occurred in the vertical burning test and a sharp increase in limiting oxygen index (LOI) values was noticed for all the treated fabric samples. CS modified PA66 fabric sample treated with a 10 wt % of DOPA exhibited a greater reduction in pHRR by 40% and showed superior flame retardant performance compared to the only DOPA treated pure fabric sample. The superb flame retardant properties of CS modified fabrics were due to the co-presence of DOPA and CS; where a synchronized gas phase and a condensed phase flame retardant mechanism was realized as DOPA showed a quenching effect in a gas phase mechanism and simultaneously, catalyzed the charring of CS in a condensed phase activity which was also justified from the TG-GC-MS analysis, TGA and FTIR analysis of char residues. However, this kind of facile application showed poor wash durability and deteriorated the physical properties of the fabric materials specifically treated with a higher DOPA content.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2020
·Vol. 43
·期 7
·1306-1315
·
IF 2.878
Le Song,Canping Pan,Juan Yang,Sujia Zeng,Yongtao Han
A rapid and effective method was developed for the analysis of 39 pesticide residues in porcine meat with dual-layer multiplug filtration cleanup and gas chromatography-tandem mass spectrometry detection. The cleanup process was performed with columns packed with two layers, namely multiwalled carbon nanotubes, C18 and anhydrous magnesium sulfate (MgSO 4 ) as top layer, while mixture of florisil and MgSO 4 as bottom layer. A single-layer method was tested in parallel, with columns packed with the same amount of absorbents. Extraction conditions and filtration cleanup process were optimized to obtain satisfied method performance. Method linearity was calculated with coefficients of determination more than 0.995. The limits of quantitation were verified with acceptable accuracy at the lowest spiked concentration of 0.01 mg/kg (except pyrimethanil). The recoveries at three fortified levels (0.01, 0.05, and 0.1 mg/kg) in five replicates were between 74 and 118% (except pyrimethanil) with relative standard deviations range from 1 to 16%. The matrix effects were in the range of 1.01 to 2.84. This new method was applied for the analysis of multipesticide residues in market samples of porcine meat. This study showed the dual-layer multiplug filtration cleanup demonstrated better performance than that with the single-layer columns in cleanup of porcine meat.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Bing Liu,Xiaochen Xu,Yuan Xue,Lifen Liu,Fenglin Yang
An integrated method of simultaneous desulfurization and denitrification from flue gas by catalytic ozonation combined with NH 3 /(NH 4 ) 2 S 2 O 8 absorption was developed for the first time. It consisted of two parts: (1) the catalytic ozonation of NO over FeO x /SAPO-34 to study the effects of the various influencing factors, and (2) the absorption–oxidation of NO x and SO 2 induced by ozone combined with a NH 3 /(NH 4 ) 2 S 2 O 8 solution in a bubble column reactor. In Part 1, results showed that under the optimal condition of a molar ratio of 0.5 for O 3 /NO, a residence time of 3 s, a water vapor volume fraction of 4%, a NO initial concentration of 536 mg/m 3 , and a SO 2 initial concentration of 343 mg/m 3 , the oxidation rate of NO was 55%. The characterizations of poisoned catalyst are briefly discussed. In Part 2, as the gas passed sequentially through the ozonizing reactor and the absorber (NH 3 /(NH 4 ) 2 S 2 O 8 solution of 0.8% ammonia and 0.2 mol/L (NH 4 ) 2 S 2 O 8 ), a NO conversion rate of approximately 92.6% and SO 2 conversion rate of 100% were obtained. The pH of the NH 3 /(NH 4 ) 2 S 2 O 8 solution had a significant impact on the NO conversion. According to the analysis of the composition of products under different pHs, a mechanism of desulfurization and denitrification based on NH 3 /(NH 4 ) 2 S 2 O 8 solutions was proposed. The reaction product as a compound fertilizer contained up to 24.5% nitrogen.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
J.L. Wang,Y.J. Guo,G.D. Long,Y.L. Tang,Q.B. Tang,X.T. Zu,J.Y. Ma,B. Du,H. Torun,Y.Q. Fu
Surface acoustic wave (SAW)-based formaldehyde gas sensor using bi-layer nanofilms of bacterial cellulose (BC) and polyethyleneimine (PEI) was developed on an ST-cut quartz substrate using sol-gel and spin coating processes. BC nanofilms significantly improve the sensitivity of PEI films to formaldehyde gas, and reduces response and recovery times. The BC films have superfine filamentary and fibrous network structures, which provide a large number of attachment sites for the PEI particles. Measurement results obtained using in situ diffuse reflectance Fourier transform infrared spectroscopy showed that the primary amino groups of PEI strongly adsorb formaldehyde molecules through nucleophilic reactions, thus resulting in a negative frequency shift of the SAW sensor due to the mass loading effect. In addition, experimental results showed that the frequency shifts of the SAW devices are determined by thickness of PEI film, concentration of formaldehyde and relative humidity. The PEI/BC sensor coated with three layers of PEI as the sensing layer showed the optimal sensing performance, which had a frequency shift of 35.6 kHz for 10 ppm formaldehyde gas, measured at room temperature and 30 % RH. The sensor also showed good selectivity and stability, with a low limit of detection down to 100 ppb.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Energy & Environmental Science
·
2019
·Vol. 12
·期 3
·1046-1054
·
IF 33.25
Siwu Li,Yuan Liu,Junwen Zhou,Shanshan Hong,Yu Dong,Jiaming Wang,Xing Gao,Pengfei Qi,Yuzhen Han,Bo Wang
Li–CO2 batteries have been developed in recent years, aiming to utilize CO2, a major cause of the greenhouse effect, as an effective energy storage medium. However, current Li–CO2 batteries still suffer from low energy efficiency, poor rate capability and short cycle life, demanding the design of more efficient CO2 cathodes. Herein, we synthesized ultrafine MnO nanoparticles dispersed in a graphene-interconnected N-doped 3D carbon framework, MnO@NC-G, by pyrolyzing a composite of a GO-wrapped metal–organic framework (MOF) containing Mn(II) active sites as the cathode material for Li–CO2 batteries. This material can enable low voltage hysteresis (0.88 V at 50 mA g−1), high rate capability (up to 1 A g−1) and long cycle life (more than 200 cycles) in cells. By comparing MnO@NC-G with four other Mn(II)-based cathodes, MnO@NC, parent Mn-MOF, MnO@KB and bulk MnO, we propose three key aspects for designing CO2 cathodes: (1) dispersed catalytic species, (2) fast electron transport, and (3) a robust interconnected network. We also found that the performance of a cycled MnO@NC-G cathode can be replenished simply by replacing the anode, indicating that the cell cycle life can be further extended with effective anode protection. Our findings here provide useful guidelines for improving the performance of Li–CO2 batteries, thus shedding light on the development of practical Li battery systems based on gaseous cathodes.
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 11
·1299-1311
·
IF 4.76
Shuangshuang Hou,Shumaila Razzaque,Bien Tan
The structural characteristics of hyper-cross-linked polymers (HCPs) make them interesting for a wide variety of applications. To form knitted HCPs various synthesis approaches including solvent knitting, a knitting method using formaldehyde dimethyl acetal (FDA) as an external cross-linker and the Scholl coupling reaction have been used. However, a systematic study of these strategies has not been explored. Here HCPs have been made using facile synthesis methodologies and characterized to reveal resulting Brunauer–Emmett–Teller (BET) surface areas up to 2278 m2 g−1 and 2064 m2 g−1 with CO2 adsorption capacities of 20.89 wt% and 18.95 wt% (at 273.15 K/1.00 bar), respectively. Detailed information is also given with respect to distinctions in textural properties, gas uptake performances and optical properties. More importantly, our comparative studies have revealed the significance and efficiency of solvent knitting when used to fabricate HCP materials with good porosities and gas uptake abilities. Among these approaches, the knitting method with FDA as an external cross-linker is the most time-efficient technique, whereas the Scholl coupling reaction has advantages for the production of fluorescent polymers. Based on the proposed mechanisms, changes in structural features can also be rationally explained.
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Haili Yu,Faqin Dong,Bowen Li,Frank S. Riehle
Rapid, reliable, and highly selective detection of SO 2 and its derivatives has an especially important practical significance in terms of environmental monitoring and human health. In this study, we describe a novel Co 2+ triggered radical reaction pathway for visual colorimetric detection of SO 2 and SO 3 2− . The reaction between Co 2+ and SO 2 or SO 3 2− with the assistance of dissolved oxygen produces highly active sulfate radical, leading to the oxidation of o-phenylenediamine (OPD). The oxidation products containing 2,3-dinitro-phenazinemethane, OPD dimer, and OPD trimer show strong UV–vis absorption. Consequently, SO 2 and SO 3 2− are quantitatively determined using the Co 2+ -OPD colorimetric detection system. This colorimetric assay exhibits a 60–650 μM and 30–70 ppm linear ranges for detection of SO 3 2− and SO 2 , respectively. The corresponding limit of detection is calculated to be 4.07 μM and 1.26 ppm for SO 3 2− and SO 2 . What is more, a distinct color change can be found at a SO 3 2− concentration of 50 μM by the naked-eye observation. The specific radical detection guarantees that the present colorimetric assay has a good anti-interference ability over common inorganic ions and gases.
✓ 已验证
产品关联
DOI
高影响因子
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
·
2019
·
IF 3.176
Wen Cui,Xiaoli Kang,Xiaoying Zhang,Zhou Zheng,Xudong Cui
Recently, Metal-organic framework (MOF) has attracted general attention as self-sacrificial template to produce metal oxide semiconductor (MOS) for gas sensing. In this work, we fabricated a porous cubic microstructure of Co 3 O 4 through the facile pyrolysis of ZIF-67. The obtained Co 3 O 4 sustained a similar cubic morphology with ZIF-67 template, but much improved pore structure was achieved. Moreover, we attempted to modify the Co 3 O 4 with Au nanoparticles . Through a facile post-synthesis adsorption & pyrolysis, the Au nanoparticles with an average size of 15–20 nm were evenly dispersed on the surface of Co 3 O 4 . Then the obtained samples were investigated for acetone gas-sensing. Results showed that both Co 3 O 4 and its Au doped structure could be used for acetone detection, while due to the existence of metal-semiconductor heterojunction and the catalysis and spillover functions of Au nanoparticles, the prepared Au/Co 3 O 4 composite showed much improved acetone response and much shortened response-recovery time than that of the bare Co 3 O 4 structure.
✓ 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）