CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 35
·期 2
·251-255
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IF 1.071
He Qian,Zhang Ying,Xiao Huajian,He Xiaohui,Zhou Xiantai,Ji Hongbing
A facile co-precipitation method was developed to prepare the novel metalloporphyrins-Ba 2+ composites with ca. 3 μm diameter and olive-like morphology. Olefins epoxidation reactions were employed to investigate their catalytic performance. Compared with the free metalloporphyrins, the composites exhibited not only the improved stability and recyclability, but also the enhanced catalytic activity. Such catalytic behaviors could be related to the unique structure of the composites, e.g., the strong interaction between R-SO 3 - and Ba 2+ ions and the uniform distribution of metalloporphyrins on the catalyst surface, respectively. Furthermore, the composites showed good compatibility with a wide range of substrates. The well-designed composites are expected to be efficient catalysts, alternative to many sophisticated-synthesized metalloporphrins-based materials, in the industrially important reactions.
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FIBERS AND POLYMERS
·
2019
·Vol. 20
·期 2
·280-292
·
IF 1.439
Shi Wenying,Li Hongbin,Du Qiyun,Wang Shuo,Zhang Haixia,Qin Xiaohong
Carboxylated multi-walled carbon nanotubes (cMWCNTs) were incorporated in membrane matrix during the drywet spinning process to improve membrane performance. Membrane surface composition and morphology were examined by means of FTIR and SEM. The effects of cMWCNTs content on membrane surface hydrophilicity, separation performance and dye adsorption properties were well investigated and characterized through WCA examination, the cross-flow filtration measurement and the adsorption experiment. The surface hydrophilicity, the water permeability, solute rejection and dye adsorption properties of the cMWNTs-incorporated hollow fiber membranes have been all improved. When cMWNTs content was 0.3 wt%, the cMWNTs-incorporated hollow fiber membrane obtained the obvious enhanced pure water flux (137.2 L·m -2 ·h -1 , at 0.1 MPa) which was 1.5 times as high as that of the original PSF hollow fiber membrane. The prepared cMWCNTs-incorporated membranes are expected to be used in the treatment of textile dyeing wastewater or employed as the supports of the composite membranes.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2019
·Vol. 411
·期 12
·2531-2543
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IF 3.286
Liu Haijian,Jia Lu,Wang Yixuan,Wang Mengyao,Gao Zideng,Ren Xueqin
In this work, a novel ratiometric fluorescent sensor, based on carbon dots (CDs) and gold nanoclusters (AuNCs), is developed for highly sensitive and selective visual colorimetric detection of Cu 2+ and alkaline phosphatase (ALP). The ratiometric fluorescent sensor was synthesized by covalently linking 11-mercaptoundecanoic acid (11-MUA)–stabilized AuNCs to the surface of amino-functionalized CD/SiO 2 nanoparticles. The red fluorescence of the AuNCs can be quenched by Cu 2+ owing to coordination between Cu 2+ and 11-MUA; however, the blue emission of the CDs was insensitive to Cu 2+ owing to the protective silica shell. The quenching of the AuNCs’ fluorescence returned when PPi was added because of the higher affinity between Cu 2+ and PPi than that between Cu 2+ and 11-MUA. In the presence of ALP, PPi was catalytically hydrolyzed into phosphate (Pi), which showed a much weaker affinity for Cu 2+ . Thus, Cu 2+ ions were released, and the fluorescence of the AuNCs was quenched once more. Based on this principle, Cu 2+ and ALP could be simultaneously detected. The developed ratiometric fluorescent sensor could detect Cu 2+ over a range from 0.025 to 4 μM with a detection limit of 0.013 μM and ALP over a range from 0.12 to 15 U/L with a detection limit of 0.05 U/L. The present method was successfully applied for the detection of Cu 2+ and ALP in real water samples and in human serum samples, respectively. This ratiometric fluorescent approach may provide a highly sensitive and accurate platform for visual Cu 2+ and ALP sensing in environmental monitoring and medical diagnosis.
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高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
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2019
·Vol. 56
·期 3
·1095-1103
·
IF 1.85
Zhang Baodong,Huang Chongxing,Zhang Linyun,Wang Jian,Huang Xingqiang,Zhao Yuan,Liu Ying,Li Cuicui
In this study, fresh mangos were packed using a custom-made antimicrobial film coated with sustained-release chlorine dioxide microcapsules. We then compared physical and chemical indexes, such as weight loss rate, firmness, chromatic aberrations, soluble solids, vitamin C, titratable acid, and other nutritional indicators, to examine changes in the mango and film during storage. Our findings revealed that control mango showed loss of edible value and commercial value after 21 days of storage, and the chlorine dioxide microcapsule antibacterial film group still retains food value and commercial value. Cross-sectional scanning electron microscopy images of the used film showed that the polylactic acid film was smooth and flat, whereas cross-sections of the antimicrobial film showed that the film was covered with voids due to deliberate release of chlorine dioxide gas during the packaging process. Thus, the antibacterial film exhibited erosion and degradation. These findings provided important insights into the use of antimicrobial films for the packaging of fruits during storage, which is essential for promoting the application of solid chlorine dioxide antimicrobial film in packaging preservation.
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JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 5
·4180-4191
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IF 2.993
Chen Peng,Yang Chao,He Zi,Guo Kunkun
A facile one-pot aqueous route is firstly proposed to fabricate the precursor of sulfonated graphene/N-doped mesoporous carbons composite (SG/NMC). SG/NMC for supercapacitor applications is subsequently obtained by thermal pyrolysis of this precursor. The obtained SG/NMC possesses the ordered mesostructures with both lattice unit parameter about 14.3 nm and much wider distributions of pore sizes, as well as delivers a specific surface area high up to 1039.65 m 2 g −1 . Likewise, SG/NMC exhibits a high specific capacitance about 304.2 F g −1 at 1.0 A g −1 , which is much higher than ordered mesoporous carbons (OMC, 128.9 F g −1 ) and N-doped mesoporous carbons (NMC, 223.3 F g −1 ). Moreover, the resultant carbon displays a capacitance of 209.2 F g −1 at a current density even up to 50 A g −1 and the capacity can be retained above 93% after 5000 cycles at 10 A g −1 . The strategy demonstrated here is therefore expected to open up new routes to fabricate graphene and mesoporous carbons composites in aqueous solutions for supercapacitor applications.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2018
·Vol. 34
·期 6
·1051-1057
·
IF 1.248
Dong Yanying,Yu Ping,Sun Qilong,Lu Yang,Tan Zhenjiang,Yu Xiaopeng
Effective molecularly imprinted membranes(MIMs) were developed as an efficient adsorbent for the selective removal of p -hydroxybenzoic acid( p -HB) from acetylsalicylic acid(ASA, aspirin). The MIMs were grafted successfully from poly(vinylidene fluoride) microfiltration membranes via reversible addition-fragmentation chain transfer(RAFT) polymerization. The graft copolymerization of acrylic acid(AA) in the presence of template p -hydroxybenzoic acid led to molecularly imprinted polymer(MIP) film coated membranes. The obtained MIMs were characterized by scanning electron microscopy(SEM), Fourier transform infrared spectrophotometer(FTIR) and Raman spectra, and batch mode adsorption studies were carried out to investigate the specific adsorption equilibrium, kinetics and selective recognition properties of different MIMs. The kinetic properties of the MIMs could be well described by the pseudo-second-order rate equation. Selective permeation experiments were performed to evaluate the permeation selectivity of the p -HB imprinted membranes. The observed performances of the MIMs are applicable to the further purification of aspirin.
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Nature Communications
·
2018
·Vol. 9
·期 1
·1-8
·
IF 12.353
Wang Huidong,Shi Yu,Wang Lu,Liu Shuai,Wu Shuwen,Yang Yihua,Feyereisen René,Wu Yidong
The cotton bollworm Helicoverpa armigera , is one of the world’s major pest of agriculture, feeding on over 300 hosts in 68 plant families. Resistance cases to most insecticide classes have been reported for this insect. Management of this pest in agroecosystems relies on a better understanding of how it copes with phytochemical or synthetic toxins. We have used genome editing to knock out a cluster of nine P450 genes and show that this significantly reduces the survival rate of the insect when exposed to two classes of host plant chemicals and two classes of insecticides. Functional expression of all members of this gene cluster identified the P450 enzymes capable of metabolism of these xenobiotics. The CRISPR-Cas9-based reverse genetics approach in conjunction with in vitro metabolism can rapidly identify the contributions of insect P450s in xenobiotic detoxification and serve to identify candidate genes for insecticide resistance.
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International Journal of Intelligent Robotics and Applications
·
2018
·Vol. 2
·期 4
·445-453
·
IF 0
Liu Yanting,Liu Yang,Shen Yajing
The bottom-up organization of noble metal nanostructures with nanometer-scale precision is an important goal in nanotechnology. Owing to their unique localized surface plasmon resonance, well-defined metal nanostructures arrays could be used to develop applications in nano-photonics, nano-plasmonics, and nano-electronics. This article proposes an alternative pathway of a controllable approach to assemble and weld together the gold nanostructures. As a typical plasmonic nanostructure, the gold nanorods (Au NRs) was synthesized by the classical seed-mediated growth method. Based on the recognition of biomolecules through complementary DNA hybridization, we used DNA origami strategy for controllable assembly of Au NRs. Rectangular DNA origami as a template can induce the geometrically assembled of Au NRs. We designed and fabricated tip-to-tip Au NRs dimers on the DNA templates. Then,the follow-up formation of nanojunctions between assembled tip-to-tip Au NRs dimers Au NRs was conducted by irradiating infrared femtosecond pulses laser. The ability to coupling plasmonic nanostructures by assembly and nano-welding could be fundamental to developing novel optical properties and ensuring materials.
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JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 5
·4115-4123
·
IF 2.993
Zhou Xiang,Zhu Ying,Ke Xiang,Zhang Kaili
In this study, we use simultaneous differential scanning calorimetry and thermogravimetric analysis to analyze the solid-state reaction characteristics of Al/Fe 2 O 3 nanothermites before n -Al melts. Different experimental setups for thermal analysis are compared, and the heat-release characteristics are studied on Al/Fe 2 O 3 nanothermites in the form of powder and pellet, respectively. It is found that protection provided by mere argon flow is far from enough for thermal analysis of Al/Fe 2 O 3 nanothermites. The experimental setup must be free of oxygen; otherwise, the determined exothermic peak is mostly the oxidation of n -Al by the residue oxygen molecules in the furnace body, due to the high reactivity and moderate accessibility of free oxygen molecules. Under proper experimental setup, it is found that besides the redox reaction between n -Al and n -Fe 2 O 3 , intermetallic reaction also occurs to form Fe 4 Al 13 . Moreover, the intermetallic reaction is more noticeable for nanothermite pellet than for nanothermite powder, and the eutectic reaction of Fe 4 Al 13 and n -Al leads to melting peaks below 655 °C. The results indicate that instrument configuration and sample status affect the testing results to a large extent, and one should be prudent to derive reaction characteristics of nanothermites.
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SN Applied Sciences
·
2018
·Vol. 1
·期 1
·1-11
·
IF 0
Huang Yangfan,Zhu Jiameng,Liu Huie,Wang Zhenyou,Zhang Xiuxia
The graphene oxide (GO) and modified carbon nanotubes (MCNTs) were dispersed in water and mixed with toluene to form homogeneous emulsion, then the porous graphene–carbon nanotubes composites (MCG) were prepared through hydrothermal reaction. The adsorption mechanism of MCG was investigated by adsorption methylene blue. The morphology of MCG was analyzed by scanning electron microscope and transmission electron microscopy. It was found that MCG had rich micropore structures and MCNTs were interlaced on graphene sheets. The pore size of MCG can be effectively controlled by changing the volume ratio of toluene to the GO/MCNTs solution in the emulsion. MCG was characterized by X-ray diffractometer, Raman spectrometer, X ray photoelectric instrument and other analytical instruments. It was found that MCG had more oxygen functional groups. The experimental results show that kinetics can be well-described by pseudo-second-order model. The smaller the pore size, the higher the equilibrium adsorption capacity and the slower the adsorption rate. The adsorption thermodynamic parameters show that the adsorption process is spontaneous and belongs to physical adsorption, and high temperature is beneficial to adsorption. The fitting results of MCG-5 equilibrium adsorption data are matched with the Langmuir model and the saturated adsorption capacity is 232 mg g −1 . After five cycles of adsorption–desorption operation, the adsorption capacity of MCG-5 decreases slightly.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 13
·12113-12121
·
IF 2.195
Ruan Xuejun,Ren Xin,Zhou Wenting,Xu Xi,Wang Xin,Wang Manyu,Yan Ying,Yao Zheng,Shi Wen,Yu Wenqi
The effect of various proportions of SiO 2 and Cr 2 O 3 doping on the micro-characteristics and the electrical properties of the ZnO varistors were investigated. As the SiO 2 /Cr 2 O 3 ratio increased, the voltage gradient increased and then decreased, the nonlinear coefficient α increased, while the leakage current showed the opposite trend, meanwhile the residual voltage ratio was almost stable. When the SiO 2 /Cr 2 O 3 ratio was 1.7 mol% vs. 0.6 mol%, the ZnO varistors sintered at 1155 °C exhibited excellent comprehensive electrical properties with voltage gradient of 329.9 V/mm, nonlinear coefficient of 65.1, leakage current of 0 µA, residual voltage ratio of 1.663, and aging starting power of 0.72 W. The varistors were in good condition after being struck 18 times of 250 A square wave energy pulse impact, showing a great potential in the industrial application of power distribution systems.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-11
·
IF 5.479
Huang Dong-Lan,Wang Jian,Cheng Fan,Ali Atif,Guo Hui-Shi,Ying Xiao,Si Li-Ping,Liu Hai-Yang
Graphene oxide (GO) was modified with the cobalt(II) and zinc(II) complexes (CoTFPP and ZnTFPP) of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin in order to improve the electrocatalytic activity of GO towards catechol (CC) and hydroquinone (HQ). It is found that the CoTFPP-modified GO on a glassy carbon electrode (GCE) displays the highest electrocatalytic activity. The response to CC (at 0.14 V vs. SCE) is linear in the 1–220 μM concentration range. The response to HQ (at 0.04 V vs. SCE) extends from 1 μM to 200 μM. The sensitivity and detection limits are 10.40 μA∙μM −1 ∙cm −2 and 0.17 μM for CC, and 8.40 μA∙μM −1 ∙cm −2 and 0.21 μM for HQ. Experimental results indicate that the Co(II) and Zn(II) ions in the porphyrins positively affect the electron transfer rate in the hybrid materials. The GCE modified with CoTFPP/GO was successfully applied to the simultaneous determination of CC and HQ in spiked samples of tap and lake water.
Schematic presentation of a voltammetric method for simultaneous determination of catechol (CC) and hydroquinone (HQ). It is based on the use of a cobalt (II) fluoroporphyrin (CoTFPP) functionalized graphene oxide (GO) hybrid.
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