COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2018
·
IF 2.829
Jinqiong Xu,Tingting Chen,Xiujuan Qiao,Qinglin Sheng,Tianli Yue,Jianbin Zheng
A novel non-enzymatic electrochemical sensor based on gold nanoparticles/nicke hydroxide nanosheet (AuNPs/Ni(OH) 2 NS) nanocomposite was successfully fabricated and further used for glucose sensing. The morphology and composition of AuNPs/Ni(OH) 2 NS were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The electrochemical properties were evaluated through cyclic voltammetry and amperometric methods. The AuNPs/Ni(OH) 2 NS/GCE exhibited wide linear range (0.002–6.0 mM), a low detection limit (0.66 μM) and good reproducibility and stability. The sensor was successfully employed for glucose detection in food samples for which the sensor displayed high performance with excellent reproducibility and recovery in complex food materials.
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ANALYTICAL CHEMISTRY
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2018
·
IF 6.042
Fato Tano Patrice,Kaipei Qiu,Li-Jun Zhao,Essy Kouadio Fodjo,Da-Wei Li,Yi-Tao Long
Inspired by the addition-elimination catalytic mechanism of natural pyrroloquinoline quinone (PQQ) containing proteins, PQQ-modified hybrid nanomaterials have been increasingly developed recently as biomimetic heterogeneous electrocatalysts. However, up until now, no existing electrochemical approach was able to assess the intrinsic catalytic activity of PQQ sites, impeding the design of efficient PQQ-based electrocatalysts. Herein, in this work, we introduced a new method to calculate the turnover frequency (TOF) of any individual PQQ functional group for electrocatalytic oxidation of tris(2-carboxyethyl)phosphine (TCEP), through the study of single PQQ-decorated carbon nanotube (CNT) collisions at a carbon fiber ultramicroelectrode by chronoamperometry. The core advantage of this approach is being able to resolve the number of PQQ catalytic sites grafted on each individual CNT, so that the charge of any CNT collision event can be accurately translated into the intrinsic activity of the respective PQQ functional groups. The resulting collision-induced current responses clearly showed that the functionalization of CNTs with PQQ could indeed enhance its catalytic performance by 3 times, reaching a TOF value of 133 s–1 at 1.0 V vs Ag/AgCl. Such a single CNT collision technique, which is proposed for the first time in this work, can open up a new avenue for studying the intrinsic (electro)catalytic performance at a molecular level.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
·
IF 6.735
Fei Zhang,Jun Hou,Lingzhan Miao,Juan Chen,Yi Xu,Guoxiang You,Songqi Liu,Jingjie Ma
Pesticide contaminants, such as chlorpyrifos (CP) and its more toxic metabolite 3,5,6-trichloro-2-pyridinol (TCP) in farmland drainage have attracted extensive concerns around the world, and are in urgent need of treatment. In this work, three groups of anaerobic reactors packed with zero valent iron (mono-ZVI system), ZVI coupled with anaerobic sludge (coupled system) and anaerobic sludge (mono-cell system) were continuously operated to investigate their performances on CP, TCP and chemical oxygen demand (COD) removal, as well as the reaction mechanisms of ZVI coupling with anaerobic microorganisms. Results showed that the removal efficiencies of CP and COD in coupled system were both around 95%. The corresponding results were 80% and 82% in mono-cell system, and the unstable values in mono-ZVI system were around 86% and 70%. The TCP residual concentration was the lowest in coupled system. The results of X-ray photoelectron spectrometer (XPS) and the photo images of ZVI at the end of reaction implied that the presence of sludge and the interaction between microorganisms and ZVI protected iron shavings from excessive corrosion. Moreover, the addition of ZVI promoted the electron transfer in the anaerobic system, which was proved by the higher value of electron transport system (ETS) activity and Cytochrome C (Cyt C ) content of sludge with 250 mg (g h) −1 and 20.71 nmol L −1 in coupled system, compared to 200 mg (g h) −1 and 17.56 nmol L −1 in mono-cell system. The improvement of extracellular polymeric substances (EPS) and anaerobic sludge granulation in the coupled system were on account of the existence of ZVI. It was obvious that the key enzymes and microbial species functioned in COD, CP and TCP degradation were enriched in coupled system.
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JOURNAL OF MATERIALS SCIENCE
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2018
·Vol. 53
·期 21
·15118-15129
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IF 2.993
Liu Hao,Xu Jü,Liu Guanxi,Wang Meiri,Li Jing,Liu Yuanyuan,Cui Hongtao
Herein, a facile sol–gel strategy for building the ordered interpenetrating network of Ni(OH) 2 and reduced graphene oxide (rGO) was proposed. In this strategy, rGO nanosheets were homogeneously fixed inside composite utilizing the pores of Ni(OH) 2 gel as template, forming rGO-interpenetrated gel network. It was found that the rGO nanosheets could effectively reduce the internal resistant of composites and provide mechanical support for the gel network of Ni(OH) 2 . Therefore, the composite presented high electrochemical performance, especially high-rate performance, due to the interpenetrating of rGO nanosheets plus the supplementary role of acetylene black. It had high specific capacitance of 2163 F g −1 at low current density of 2.9 A g −1 and 733 F g −1 at high current density of 86.8 A g −1 .
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Chemical Engineering and Processing-Process Intensification
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2018
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IF 2.826
Yanyan Guo,Chengna Dai,Zhigang Lei
A series of Pd-La/SiO 2 /cordierite (cordierite = COR) and Pd-Zn/SiO 2 /COR bimetallic monolithic catalysts were prepared, characterized, and tested for the hydrogenation of 2-ethylanthraquinone (eAQ) as the key step of anthraquinone method for production of H 2 O 2 . It was found that the metal particle size is remarkably dependent on the Pd/M (M = La, and Zn) mass ratio of bimetallic monolithic catalysts. By virtue of its small metal particle size and the strong interaction, the 0.8% Pd-0.4% La/SiO 2 /COR monolithic catalyst presents the highest H 2 O 2 yield (7.7 g L −1 ) and selectivity toward active quinones (95%), which is attributed to the addition of La leading to the synergistic effect between Pd and La. Moreover, the density functional theory (DFT) calculations for the adsorption of eAQ over the surface of Pd-La/SiO 2 /COR and Pd-Zn/SiO 2 /COR bimetallic monolithic catalysts have been conducted to further understand the mechanism of molecule–surface interactions between eAQ and the PdM(1 1 1) or Pd(1 1 1) surfaces. Detailed studies showed that the high catalytic activity of Pd-La/SiO 2 /COR bimetallic monolithic catalyst is attributed to the stronger adsorption between Pd 3 La 1 (1 1 1) and the carbonyl group of eAQ.
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Pharmaceutics
·
2019
·Vol. 11
·期 5
·214
·
IF 4.773
Qing Min,Xiaofeng Yu,Jiaoyan Liu,Jiliang Wu,Ying Wan
Chitosan(CH)-poly(dioxanone) (CH-PDO) copolymers containing varied amounts of PDO and having free amino groups at their CH backbone were synthesized using a group protection method. The selected CH-PDO with soluble characteristics in aqueous media was used together with hyaluronic acid (HA) to prepare HA/CH-PDO polyelectrolyte complex nanoparticles (NPs) via an ionotropic gelation technique, and such a type of HA/CH-PDO NPs was employed as a carrier for delivering bone morphogenetic protein-2 (BMP-2). The optimal BMP-2-encapsulated HA/CH-PDO NPs with high encapsulation efficiency were embedded into CH/glycerophosphate composite solutions to form different hydrogels in order to achieve long-term BMP-2 release. The formulated gels were found to be injectable at room temperature and had its thermosensitive phase transition near physiological temperature and pH. They also showed abilities to administer the release of BMP-2 in approximately linear manners for a few weeks while effectively preserving the bioactivity of the encapsulated BMP-2. In view of their fully biocompatible and biodegradable components, the presently developed gel systems have promising potential for translation to the clinic use in bone repair and regeneration where the sustained and controlled stimuli from active signaling molecules and the stable biomechanical framework for housing the recruited cells are often concurrently needed.Keywords:chitosan;hyaluronic acid;nanoparticles;hydrogel;bone morphogenetic protein-2
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高影响因子
JOURNAL OF LUMINESCENCE
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2018
·
IF 2.732
YaoYao Qu,Guojuan Ren,Liying Yu,Baoya Zhu,Fang Chai,Lihua Chen
Herein, the fluorescent carbon dots (CDs) has been synthesized by hydrothermal method by using ethylene diamine tetraacetic acid (EDTA) as a raw materials. The prepared CDs exhibited bright blue fluorscence excited by 340 nm with the quantum yield as high as 52%. The CDs possess special fluorescence responses to 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP), and the slump of fluorescence was demonstrated by CDs solution in the case of 2-nitrophenol and 4-nitrophenol existence. The detection limit of 2-NP and 4-NP was calculated at 77 nM and 60 nM, respectively. Meanwhile, the color response to 2-NP and 4-NP can be observed from achromatic solution to yellow by naked eye. All in all, the obtained CDs can be applied as fluorescence and colorimetric probe in environmental protection.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
·
IF 6.735
Kiran Gupta,Jiang-Bo Huo,Jia-Cheng E. Yang,Ming-Lai Fu,Baoling Yuan,Zhangxu Chen
We introduced (MoS 4 ) 2− moiety into the lamellar layers of Ca 0.66 Al 0.34 (OH) 2 (NO 3 ) 0.34 ⋅yH 2 O to fabricate Ca 0.66 Al 0.34 (OH) 2 (MoS 4 ) 0.17 ⋅yH 2 O (CA-MoS 4 ⋅LDH), a stable and efficient adsorbent for removal of two envoy Fluoroquinolones (FQs), Ciprofloxacin (CIP) and Ofloxacin (OFL), from contaminated aquatic sources. Various characterization tools, such as X-ray diffraction (XRD), Scanning electron microscopy, Energy dispersive X-ray spectrometer, transmission electron microscopy , X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and Thermogravimetric analyses etc. were applied to confirm structural and compositional changes during the synthesis and adsorption properties of CA-MoS 4 ⋅LDH. The efficiency of adsorbent was investigated by evaluating different parameters including contact time, pH of solution, initial concentration of pollutant, and effect of temperature. By using CA-MoS 4 ⋅LDH as adsorbent, we found more efficient removal of CIP than that of OFL due to the steric hindrance. The highest uptake of 707.20 mg/g and 476.74 mg/g of CIP and OFL, respectively, was found at pH of 6 with improved kinetics and easily reusability for these representative antibiotics models so far. Removal kinetics of both FQs were found to better follow the pseudo-second-order kinetic model than the pseudo-first-order. The Langmuir adsorption isotherm was employed to understand the removal process, suggesting monolayer chemisorption mechanism. The adsorbate-adsorbent interaction revealed remarkable features originate from the combination of weak hydrogen bond interaction between thio group and NH 2 + group of antibiotic and electrostatic interaction between positive LDH layer and COO − group of antibiotic as well, and anion exchange mechanisms, which were also confirmed by XRD, FTIR, XPS and Raman spectrum etc. obtained after adsorption. It is proposed that all (MoS 4 ) 2− moiety offers stability to the CA-MoS 4 ⋅LDH structure to avoid its solubility under ambient environments.
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ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
·
2015
·Vol. 641
·期 11
·1953-1958
·
IF 1.16
Yunsheng Liu,Dajiang Mei,Jingli Xu,Yuandong Wu
Sodium magnesium selenite NaMg 2 (OH)(SeO 3 ) 2 and rubidium zinc selenite RbZn 2 (OH)(SeO 3 ) 2 were prepared by hydrothermal reactions. The crystal structures of the title compounds were determined by single-crystal X-ray diffraction. NaMg 2 (OH)(SeO 3 ) 2 crystallizes in the orthorhombic space group Pnma (no. 62) with lattice parameters a = 13.1919(10), b = 6.0415(4), c = 8.2182(6) Å, and Z = 4 and RbZn 2 (OH)(SeO 3 ) 2 crystallizes in the triclinic space group P (no. 2) with lattice parameters a = 4.8698(5), b = 7.3446(8), c = 11.7796(12) Å, α = 82.554(3), β = 78.456(2), γ = 71.603(3)°,and Z = 2. The structure of NaMg 2 (OH)(SeO 3 ) 2 is a three-dimensional framework consisting of edge-sharing MgO 6 octahedra and trigonal pyramidal SeO 3 2– groups, whereas the structure of RbZn 2 (OH)(SeO 3 ) 2 is a two-dimensional layers structure consisting of corner-sharing [Zn 2 O 7 ] dimers linked by trigonal pyramidal SeO 3 2– groups. The compounds were characterized by the solid state UV/Vis/NIR diffuse reflectance, and FT-IR spectroscopy.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 132
·期 29
·
IF 1.768
Lei Wang,Wen Huang,Shijie Wang,Yuezhi Cui,Pengfei Yang,Xiaodeng Yang,Jonathan V. M. Weaver
pH-Responsive amphiphilic branched copolymers were prepared from poly(ethylene glycol) methyl ether methacrylate (PEGMA), 2-(diethylamino)ethyl methacrylate (DEAEMA), 2-( tert -butylamino)ethyl methacrylate ( t BAEMA), and ethylene glycol dimethacrylate (EGDMA) utilizing a thiol-modified free radical polymerization. The molecular structures of copolymers were confirmed by proton nuclear magnetic resonance spectroscopy ( 1 H NMR) and triple-detection gel permeation chromatography (tri-GPC). The aqueous solution behaviors of the obtained copolymers were investigated by dynamic light scattering (DLS). The DLS data showed that about 16 nm polymer particles comprising of hydrophobic poly( tert -butylamino)ethyl methacrylate (P t BAEMA) and poly(diethylaminoethyl methacrylate (PDEAEMA) core, hydrophilic PEGMA corona were formed above pH 8. With the decrease of pH from 8 to 6, a dramatic increase in the hydrodynamic radius of polymer particles from 16 nm to 130 nm was observed resulting from the protonation of the PDEAEMA segment. Moreover, in vitro drug release behaviors of the resulting polymer assemblies at different pH values were also investigated to evaluate their potential as sustained release drug carriers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42183.
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ACS Applied Materials & Interfaces
·
2014
·
IF 5.9
Zhi Chen,Zanyong Zhuang,Qing Cao,Xiaohong Pan,Xiong Guan,Zhang Lin
The mechanism of the interaction between nano-Mg(OH)2 adsorbent and uranyl in water was studied. At trace levels, the uranyl is adsorbed as a monolayer on nano-Mg(OH)2, and occupied a small proportion of the adsorption sites. As the uranyl concentration crosses over a threshold, continuous increase of adsorption capacity takes place. It indicates that, by taking the pre-adsorbed uranyl as the nucleation centers, the additional uranyl crystallizes and forms U-rich nanocrystals well-scattered on the surface of nano-Mg(OH)2. A strategy of inducing fast crystal growth of nano-Mg(OH)2 to micrometer-sized Na2Mg(CO3)2 enables the desorption and enrichment of uranyl. The recycling and reuse of nano-Mg(OH)2 can be achieved simultaneously. The finding in this work provides fundamental understanding of the efficient usage of nano-Mg(OH)2 in practical applications.
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高影响因子
Catalysis Science & Technology
·
2013
·Vol. 4
·期 3
·773-779
·
IF 3.753
Qinzhuo Zhou,Bo-Geng Li,Suyun Jie,Na Zheng
A series of phosphine-containing cobalt complexes [CoCl2(PRPh2)2, R = Ph (1), Cy (2), nPr (3), Et (4), Me (5), H (6)] has been used for the highly active and stereospecific polymerization of 1,3-butadiene upon activation with ethylaluminum sesquichloride (EASC). The high catalytic activities and polybutadienes with high cis-1,4 selectivity were obtained in the solution polymerization in toluene. The conversion of butadiene and the microstructure and molecular weight of the resulting polymers were affected by reaction parameters and the R group on the phosphine ligand. The dispersion medium was also a sensitive factor for the current catalytic systems, influencing the catalytic activity and properties of products. In comparison with the solution polymerization in toluene, the heterogeneous polymerization in isooctane yielded slightly lower catalytic activity, cis-1,4 content and molecular weight under similar reaction conditions.
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