MICROCHEMICAL JOURNAL
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2019
·
IF 3.206
Yinhui Yi,Lirong Liu,Wei Zeng,Baohe Lv,Gangbing Zhu
Being awfully harmful to the environment and human health, the sensitive and selective determination of p-dihydroxybenzene (p-DHB) in environmental water is of great significance. However, the similar structures and properties of p-DHB with catechol (CC; one p-DHB isomer) make the selective and reliable determination of p-DHB from CC in environmental waters being still a formidable challenge. In this manuscript, by preparing CC stabilized silicon quantum dots (C-SiQDs) via a simple hydrothermal process and using C-SiQDs simultaneously as a catalyst and fluorescence indicator, a novel nanosensing platform was successfully developed to selectively and sensitively detect p-DHB with double signals: fluorescence and colorimetric. For detecting p-DHB, C-SiQDs could catalyze the oxidation of p-DHB to form benzoquinone (BQ), an intermediate, which lead to the color change from pale yellow to dark brown and the efficient quenching the fluorescence of C-SiQDs. While for CC in samples, it could not contact C-SiQDs surface due to the great steric hindrance effect from CC on quantum dots surface, thus restricting the oxidation of CC and production of BQ, and leading that the obtained C-SiQDs have no response towards CC. Meanwhile, the developed nanosensor could also avoid various other possible interferences. Under optimized conditions, wide linear ranges (from 0.01 μM to 50.0 μM) and low detection limits (4.0 nM) were obtained for p-DHB. The simple and reliable C-SiQDs-based double signals proposal demonstrated to be potentially applicable for the highly selective and sensitive detection of trace p-DHB in various environmental water samples.
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CHEMICAL ENGINEERING JOURNAL
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2019
·
IF 8.355
Mei Xiang,Dongfang Wu
A detailed investigation was carried out to develop novel pore- and morphology-controllable ETS-10 zeolite. The XRD , N 2 adsorption/desorption, SEM, TEM and 29 Si NMR MAS results proved that a series of hierarchical ETS-10 zeolites was successfully synthesized and more importantly, their morphologies and pore sizes can be freely confined in the desired range under the mesoporogen, morphology- and structure-directing actions of different additives. What's more, the close relationship between various additives and raw materials especially titanium source was discussed, which played an active part in morphology change and hierarchical pores formation. This can be ascribed to the special reducibility of inorganic Ti source, system liquidity and pH, and the enhanced inorganic species dissolution. Finally, the synthesized hierarchical ETS-10 materials were used as heterogeneous catalysts for different biomass-derivatives hydrogenation. Remarkably catalytic performance can be attributed to the unique TiO 6 octahedra carrying two negative charges that strengthens the interaction with active metal species, and thus improves their dispersion. Moreover, the inherent strong Lewis basicity and moderate Lewis acidity favor the oriented conversion of reactants. The controllably hierarchical structure and morphology benefit exposure of more highly dispersed active sites and prolong the catalyst life circle. Especially, an analogous molecular-recognition pattern was found by using sodium lignosulphonate, which is identified as the leading role in noticeably enhancing the catalytic activity and selectivity of the correspondingly ETS-10-based catalyst.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 3
·1-9
·
IF 5.479
Ma Yujun,Yu Ying,Lin Bixia,Zhang Li,Cao Yujuan,Guo Manli
Copper nanoclusters (CuNCs) were synthesized starting from glutathione and copper(II) nitrate. They show blue fluorescence peaking at 432 nm when excited at 334 nm. In the presence of o -phenylenediamine (OPD), the blue fluorescence is decreased, but a yellow fluorescence appears with a peak at 557 nm. UV-visible absorptiometry, fluorometry and fluorescence lifetime measurements were used to show that OPD is oxidized by the small fraction of copper(II) ions present in the CuNCs to form the oxidized form of o -phenylenediamine (oxOPD) which displays weak yellow fluorescence, while the blue fluorescence decreases. The ratio of fluorescences at 557 and 432 nm increases linearly in the 0.15 to 110 μg·L −1 OPD concentration range, and the detection limit is 93 ng·L −1 . Compared to the method based on the use of dissolved Cu(II), the employment of CuNCs reduces the detection limit by a factor of 40. The method was applied to the determination of OPD in spiked environmental water and industrial wastewater samples. Recoveries ranged from 96.8 to 100.3%.
Schematic presentation of a ratiometric fluorometric method for detection of o-phenylenediamine (OPD) based on copper nanoclusters (CuNCs). OPD is oxidized by Cu 2+ present in CuNCs to form the oxidized form of o -phenylenediamine (oxOPD). FRET occurred between oxOPD and CuNCs, and the F 557 /F 432 value is amplified.
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高影响因子
FUEL PROCESSING TECHNOLOGY
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2019
·
IF 4.507
Tao Xie,Jing-Pei Cao,Chen Zhu,Xiao-Yan Zhao,Ming Zhao,Yun-Peng Zhao,Xian-Yong Wei
Selectively cleaving the C O bonds in lignin to produce aromatic products are challenging problems. Currently, catalytic hydrogenolysis of C O bonds in lignin requires harsh conditions. Herein, selectively cleaving C O bond of benzyl phenyl ether (BPE) was studied over Pd/AC, Ru/AC and Ni/AC. Among these catalysts, Pd/AC efficiently cleaved C O bond in BPE under super mild conditions (25 °C, 2 h and 0.1 MPa H 2 ). The products were toluene and phenol without hydrogenation of the aromatic ring . The main competitive step of hydrogenolysis and hydrogenation is sensitive to reaction temperature over Pd catalyst. A mild temperature is preferred for hydrogenolysis, since the H species nearby the oxygen atom are more strongly adsorbed than nearby the benzene rings . With the different H-donor solvents, the highest conversion of BPE was obtained in isopropanol. Based on the experiments, the reactions occurred via cleavage of the C aliphatic -O bond in BPE and the synergetic effects between the H from absorbed H 2 on the surface of the Pd and the intermediates radicals of benzyl and phenoxy should be the key points to such an optimum result.
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SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2019
·Vol. 26
·期 1
·261-269
·
IF 0.705
Xiazhi Zhou,Wei Zhou,Dianchun Ju,Yinxian Peng,Lei Zhou,Sheng Tang,Jing Wang
In this work, hierarchical porous resins (PRs) are fabricated and applied as novel adsorbent for removal of oily substance. The oil/water (o/w) high internal phase emulsions (HIPEs), stabilized by phenolic resin precursor and tween 80, were used as the template for simultaneous polymerization of aqueous phase, methenamine, sodium persulfate and liquid paraffin. Subsequently, dopamine hydrochloride, 1-dodecanethiol and Fe 3 O 4 particles are grafted onto the interface of PRs via adhesion of dopamine and Markel addition reaction between quinone groups on dopamine and sulfhydryl groups on 1-dodecanethiol. The as-prepared composites possessed hydrophobicity and magnetic property (HPRs). The physical and chemical properties, morphology and adsorption properties of HPRs are characterized by XRD, FT-IR, TGA, SEM, N 2 adsorption-desorption isotherms. The as-synthesized HPRs composites had a typical hierarchical porous structure, and the resulted macropores with a well-defined open-cell and interconnecting pore throat structure could be controlled via the composition of the aqueous phase of emulsion. The hierarchical porous structure of HPRs contained macropores ranging from 0.3 μm to 4 μm and mesopores of 11.26 nm. HPRs have rough and hydrophobic surface (water contact angle of 130 ∘ ) with specific surface area of 15.06 m 2 /g and pore volume of 0.0349 cm 3 /g. The oil adsorption rate and the oil retention rate for toluene are 11.765 g/g and 86.43%, respectively. The oil adsorption rate in the first minute can reach more than 80% of the highest oil adsorption rate. The oil adsorption rate of HPRs after three recycling experiments can still reach 87.32%of the first-time oil adsorption rate.
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POLYMER COMPOSITES
·
2019
·Vol. 40
·期 11
·4248-4256
·
IF 2.268
Shuai Zhao,Jian Cui,Guangfa Zhang,Ailin Gao,Yehai Yan
Phenolic resin (PR) grafted graphene (G-PR), synthesized from the versatile graphene modification platform 2-(3, 4-dihydroxyphenyl) pyrrolidine grafted pristine graphene (G-OH), is used to develop high-performance phenolic composites. Benefiting from good properties of G-PR, uniform dispersion of G-PR and strong PR/G-PR interfacial interaction, G-PR shows obvious advantages as a filler in improving mechanical, electrical, and thermal properties of PR over pristine graphene (pG) and graphene oxide (GO) derivatives. For PR/G-PR composites, the maximum tensile strength attains 51.4 MPa at 0.5 wt% graphene content. Electrical and thermal conductivities reach to 10 −3 S·cm −1 and 0.374 W·m −1 ·k −1 at 5 wt% graphene content, respectively. The decomposition temperature and residue at 800°C separately increase by 61°C and 3.5 wt% at 1 wt% graphene content. In a word, this contribution provides an alternative avenue for preparing high-performance and multifunctional PR/graphene composites, avoiding the high risk and serious pollution of graphene oxide (GO) avenue.
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ANALYTICA CHIMICA ACTA
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2019
·
IF 5.256
Chuyi Ni,Junlong Huang,Xintong Xie,Yueru Shi,Juan Zheng,Gangfeng Ouyang
Ordered mesoporous carbons (OMCs) are a kind of remarkable adsorbents in environment area due to high surface area, controllable pore size and superior stability. However, the inherent hydrophobicity and strong π-π interaction make OMCs have an advantage for the adsorption of nonpolar pollutants, leading to great demands for the development of new-type OMCs with outstanding adsorption efficiencies towards polar pollutants. The zirconium and nitrogen co-doped ordered mesoporous carbon (Zr/N-OMC) was obtained by directly carbonizing the composites of phenolic resin and UiO-66-NH 2 , with uniform mesopore structure, large surface area (583 m 2 g −1 ) and widely dispersed heteroatoms . Due to these prominent properties, the Zr/N-OMC was fabricated as high-performance solid phase microextraction coating. The results proved that the doping zirconium and nitrogen could act as active sites to interact with polar pollutants, resulting in fast adsorption rate and enhanced adsorption capacity. Therefore, the high-performance Zr/N-OMC-coated fiber was coupled with gas chromatography-mass spectrometry to establish sensitive analytical method for the detection of trace phenols from real water samples. This work would open up a new avenue for simple and efficient modification of OMC with enhanced adsorption performance to expand applications.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 8
·B562
·
IF 3.12
Long Wu,Heng Yan,Jing Wang,Guojiao Liu,Weihong Xie
Based on tyrosinase modified Au-Pt@SiO2/Au-graphene (APS/Au-GN) electrode, a highly sensitive biosensor was developed for the direct electrochemical detection of bisphenol A (BPA) in food matrices. In this work, Au-graphene (Au-GN), Au-Pt@SiO2 nanocomposites (APS NPs) and tyrosinase (Tyr) were subsequently cast on glass carbon electrode (GCE) via the electrostatic interaction and Van der Waals force. The self-assembled APS NPs and Tyr were decorated on Au-GN forming a new hierarchical three dimensional nanostructure. Due to the dense Au/Pt dots distributed on silica nanoparticles, APS NPs could behave excellent catalytic activity and stability. In this regard, BPA could be sensitively detected by square wave voltammetry (SWV) and differential pulse voltammetry (DPV) with well-defined oxidation peaks at 480 mV and 660 mV, respectively. Under the optimal conditions, SWV detection behaved good analytical performance toward BPA with a wide linear response ranging from 0.01 mg L−1 to10 mg L−1. The detection limit of APS/Au-GN/GCE for BPA was 1.80 μg L−1 (S/N = 3). Moreover, the method showed good reproducibility in practical samples with recoveries from 87.4% to 110.7%, suggesting its potential application in food analysis and safety verification.
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Foods
·
2019
·Vol. 8
·期 8
·308
·
IF 3.011
Huali Chen,Gengsheng Xiao,Yujuan Xu,Yuanshan Yu,Jijun Wu,Bo Zou
The aim of this study was to evaluate the effect of high hydrostatic pressure (HHP) and co-fermentation byLactobacillus rhamnosusandGluconacetobacter xylinuson the quality of yacon-litchi-longan (YLL) juice. The carbohydrates, organic acids, free amino acids (FAAs), and volatile compounds in YLL juice were analyzed. Thermal processing (TP) increased the content of total carbohydrates, organic acids and FAAs, and destroyed the aroma components, whereas HHP treatment had a negligible effect. Carbohydrate content was lower, and content of lactic acid, acetic acid, and exopolysaccharide (EPS) were higher in co-fermented juice than in unfermented juice. Furthermore, the content of bitter FAAs in fermented TP and HHP-treated YLL juices decreased by 88.7% and 86.9%, respectively. Co-fermentation also increased ketones and the sum of individual volatile constituents, and improved the overall flavor of juice. Taken together, HHP treatment prior to co-fermentation can be used to improve the quality of YLL juice, especially the flavor thereof.Keywords:high hydrostatic pressure;Lactobacillus rhamnosus;Gluconacetobacter xylinus;free amino acids;volatile flavor compounds
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Weixue Wang,Qiaobin Gong,Zhe Chen,Weidong Devin Wang,Qiang Huang,Shuang Song,Jianrong Chen,Xiangke Wang
Phenolic contaminants existed widely in ecological environment. Due to the various structure and functional groups, the interaction behavior of phenolic organic compounds with adsorbent was complex and changeable. Therefore, the exploration of adsorption and competition about phenolic compounds on solid-liquid interface in aqueous solution is of great significance. Herein, through a simple sugar-blowing route and post-oxidation modification, a free-standing, large-scale nanoporous three-dimensional graphene oxide (3D GO) was achieved. The synthesized 3D GO possessed hierarchical interconnected porous structure and abundant active sites, which showed excellent removal performance for many phenolic compounds. The maximum adsorption capacity ( q max ) was 135.6 mg/g, 191.3 mg/g, 237.7 mg/g, 398.6 mg/g, 420.9 mg/g and 585.8 mg/g for phenol, 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP), bisphenol-A (BPA) and 2,4,6-trichlorophenol (TCP) at 25 °C respectively. The competitive adsorption between BPA and TCP on 3D GO was also explored. Batch adsorption experiments and characterization revealed that the outstanding performance benefited from various factors, including structural advantage, electrostatic interaction, π-π interaction, hydrophobic effect, hydrogen bond, the synergy of heteroatom and the new active sites of preferential adsorbed organics. The cost-effective and highly active 3D GO adsorbent showed great promising in environmental field, and supplied insight to understand the underlying behavior of phenolic compounds on the solid-liquid interface.
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Soft Matter
·
2019
·Vol. 15
·期 31
·6411-6417
·
IF 3.399
Xun Tong,Yuan Qiu,Xiaoyu Zhao,Bijin Xiong,Rongzhen Liao,Haiyan Peng,Yonggui Liao,Xiaolin Xie
Photoresponsive supramolecular gels have aroused continuous attention because of their extensive applications; however, most studies utilize UV light, which inevitably brings about some health and environmental issues. The halogen bond is an important driving force for constructing supramolecules due to its high directionality, tunable strength, good hydrophobicity, and large size of the halogen atoms. Yet, it still remains a formidable challenge to utilize halogen bonds as a driving force to fabricate a visible light responsive gel. In this work, to fabricate such a gel, azopyridine-containing Azopy-Cn (n = 8, 10, 12) was selected as a halogen bond acceptor, while 1,2-bis(2,3,5,6-tetrafluoro-4-iodophenyl)diazene (BTFIPD) was chosen as both the halogen bond donor and visible light responsive moiety. The visible light response of BTFIPD resulted from the significant separation of n–π* energy levels between trans and cis isomers due to the introduction of an electron-withdrawing group (fluorine) to azobenzene at the ortho-position. Interestingly, the gel exhibited a good gel-to-sol transition behavior upon green light irradiation. At the same time, the morphologies varied from uniform narrow flakes to broad sheets with increasing illumination time. We provide an environmentally-friendly visible light-triggered method to regulate the phase transition of supramolecular materials in applications ranging from energy conversion to information storage.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Mingzhu Yu,Lina Wu,Jiaona Miao,Wei Wei,Anran Liu,Songqin Liu
We developed a new electrochemical sensor based on TiO 2 and polypyrrole (PPy) molecularly imprinted polymer (MIP) nanocomposites for the high selective detection of p-nonylphenol in food samples, which is considered as a kind of endocrine disrupting chemical and harmful to human health. With p-nonylphenol as template molecules, the molecularly imprinted polymer was synthesized by the chemical oxidative polymerization of pyrrole and deposited on the surface of TiO 2 nanoparticles to form partially encapsulated PPy@TiO 2 nanocomposites, denoted as NP-PPy@TiO 2 MIP. p-Nonylphenol was bound in the PPy matrix through hydrogen bond and π-π interaction between p-nonylphenol and PPy skeleton. NP-PPy@TiO 2 MIP nanocomposites were modified onto glassy carbon electrode (GCE) and p-nonylphenol molecules were excluded from PPy layers by potentiostatic sweeping at the potential of 1.3 V. The as-prepared electrochemical sensor obtained a large amount of micro cavities in PPy layer which could specially recognize and combine target molecules p-nonylphenol. After special adsorption of p-nonylphenol from samples, p-nonylphenol embedded in the PPy layer exhibited a strong differential pulse voltammetry (DPV) response at 0.56 V, which can be used for the detection of p-nonylphenol with a linearly proportional concentration range of 1.0 × 10 −8 to 8 × 10 −5 mol/L and a detection limit of 3.91 × 10 −9 mol/L. The good stability, reproducibility and specificity of the resulting MIP electrochemical sensor are demonstrated. It might open a new window for investigation of selectively electrochemical sensing of small organic molecules from their analogues with the molecular imprinting technique.
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高影响因子
危险品化学品经营许可证（带存储）