SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2019
·
IF 2.931
Xinchun Zhou,Jing Shi,Jing Zhang,Kang Zhao,Anping Deng,Jianguo Li
A novel, rapid and convenient competitive immunoassay for ultrasensitive detection of chloramphenicol residues in shrimp and honey was established combined with flow injection chemiluminescence. The carboxylic resin beads were used as solid phase carriers to load with more coating antigen due to their larger specific surface area and good biocompatibility. The surface of the silica dioxide nanoparticles was modified with aldehyde group to combine with more horseradish peroxidase and the chloramphenicol antibody. There was a competitive process between the chloramphenicol in solution and the immobilized coating antigen to combine with the limited binding site of antibody to form the immunocomplex. Silica dioxide nanoparticles played an important role in enhancing chemiluminescence signal, because the horseradish peroxidase on SiO 2 effectively catalyzed the system of luminol-PIP-H 2 O 2 . Under optimal conditions, the chemiluminescence intensity decreased linearly with the logarithm of the chloramphenicol concentration in the range of 0.0001 to 100 ng mL −1 and the detection limit (3σ) was 0.033 pg mL −1 . This immunosensor demonstrated acceptable stability, high specificity and reproducibility. The horseradish peroxidase-silica dioxide nanoparticle-chloramphenicol antibody complex successfully prepared in this article was firstly applied to the detection of chloramphenicol, and had extremely important meanings for the application of nanoparticles and enzymatic catalysis in the field of chemiluminescence.
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高影响因子
Polymers
·
2019
·Vol. 11
·期 9
·1483
·
IF 3.164
Nanjun Lai,Lei Tang,Na Jia,Dongyu Qiao,Jianlin Chen,Yong Wang,Xubin Zhao
To improve oil recovery significantly in low-mid permeability reservoirs, a novel modified nano-SiO2hyperbranched copolymer (HPBS), consisting of polyacrylamide as hydrophilic branched chains and modified nano-SiO2as the core, was synthesized via an in situ free radical polymerization reaction. The structure and properties of the hyperbranched copolymer were characterized through a range of experiments, which showed that HBPS copolymers have better stability and enhanced oil recovery (EOR) capacity and also smaller hydrodynamic radius in comparison with hydrolyzed polyacrylamide (HPAM). The flooding experiments indicated that when a 1000 mg/L HPBS solution was injected, the resistance factor (RF) and residual resistance factor (RRF) increased after the injection. Following a 98% water cut after preliminary water flooding, 0.3 pore volume (PV) and 1000 mg/L HPBS solution flooding and extended water flooding (EWF) can further increase the oil recovery by 18.74% in comparison with 8.12% oil recovery when using HPAM. In this study, one can recognize that polymer flooding would be applicable in low-mid permeability reservoirs.Keywords:modified nano-SiO2;hyperbranched copolymer;enhanced oil recovery;low-mid permeability reservoir
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SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Nianbing Zhong,Ming Chen,Haixing Chang,Tianheng Zhang,Zhengkun Wang,Xin Xin
We present a high-selectivity photochemical fiber-optic sensor in which a plastic optical fiber (POF), TiO 2 -based composite, and polymer membrane are coupled for detection of phenol concentrations in water. A thinned POF is coated with TiO 2 -based composite, which is composed of Er 3+ :YAlO 3 /SiO 2 /TiO 2 (EYST) and acts as the sensing region. The EYST coating shows good light-inducing capacity at the core–coating interface and high photocatalytic activity in the visible light region. The polymer membrane is synthesized using PEBA2533 doped with β-cyclodextrin and shows high phenol selectivity and permeability; thus, phenol molecules can freely permeate the membrane and are then transferred, become attached to the surface of TiO 2 nanoparticles, and are photocatalytically degraded. Photocatalytic degradation of phenol improves the refractive index (RI) and absorbance of the solution because of the photocatalytic byproducts; consequently, the transmitted output light intensity of the sensor changes, and the phenol concentration is accurately detected by measuring the change in the light intensity. Experimental results indicate that the prepared device detects phenol in water with high selectivity and pH independence; in phenol detection, the novel sensor shows a sensitivity of −0.195 × 10 −3 (mg/L) −1 and a low limit of detection of 40 μg/L.
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RESEARCH ON CHEMICAL INTERMEDIATES
·
2018
·Vol. 44
·期 10
·6369-6385
·
IF 1.674
Chen Zhangxu,Fu Ming-Lai,Huang Xiao-Dan,Yuan Baoling,Yang Jia-Cheng E.
To enhance photocatalytic activity spectra area of the TiO 2 based photocatalyst, and to separate and recycle photocatalyst easily, magnetic photocatalyst was prepared with β-NaYF 4 :Yb 3+ ,Tm 3+ , TiO 2 , Fe 3 O 4 as carriers, and tetraethyl orthosilicate as precursor. The magnetic infrared responsive photocatalysts were thoroughly characterized by field emission scanning electron microscopy, X-ray diffraction, a fluorescence spectrometer and UV–Vis–NIR diffuse reflectance spectroscopy. They showed that the composite of β-NaYF 4 :Yb 3+ ,Tm 3+ /TiO 2 /Fe 3 O 4 @SiO 2 (UCTFS) emits visible luminescence upon 980 nm excitation, and energy transfer from β-NaYF 4 :Yb 3+ ,Tm 3+ to TiO 2 was verified. The photocatalytic activities of the UCTFS were studied by orthogonal experiments for photodegradating methylene blue (MB). The degradation rate of MB can reach 86.69% under the optimal conditions. After the four recycles, the degradation rate remained 52.72%. It also showed that 50.27% of the degradation efficiency of phenol can be obtained under the same experimental parameters. These results suggest that magnetic UCTFS composite is stable and a magnetic NIR-driven photocatalyst for degradation of organic pollutants. Moreover, the NIR driven photocatalytic mechanism of this reported composite was proposed. The strategy suggested here may be indicated for the effective fabrication of magnetic NIR-driven photocatalyst for application in the water purification by full spectra of solar energy.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 29
·期 24
·20546-20553
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IF 2.324
Xin Miao,Zhang Liming,Chang Yi,Ren Luchao,Luo Xianfu,Zhou Hongqing
This present work aimed to attain a high-performance tape for LTCC application by using butyl benzyl phthalate as plasticizer in tape casting slurry of CaO–SiO 2 –B 2 O 3 glass–ceramics. The plasticizing mechanism of butyl benzyl phthalate in suspensions was demonstrated in depth. Dried droplets of binder were prepared to preliminarily judge the compatibility of binder and plasticizer, and the optimal additive amount was determined by rheological characteristic. In addition, a series of qualitative and quantitative methods were carried out to assess the tensile strength and elongation of green tapes, microwave properties and densification of sintered bodies. The experimental results revealed that when the addition of BBP was up to 45 wt%, tape casting slurries had the optimal fluidity and green tapes obtained the excellent performance with density at 1.65 g/cm 3 , tensile strength at 1.43 MPa and elongation at 13.4%. Meanwhile, sintered bodies fired at 850 °C achieved the highest density at 2.42 g/cm 3 with ε r = 5.94 and tanδ = 10 × 10 −4 at 10 GHz.
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RSC Advances
·
2018
·Vol. 8
·期 59
·34069-34077
·
IF 2.936
Minhua Zhang,Xuechao Tan,Tong Zhang,Zheng Han,Haoxi Jiang
A deactivation study on the ethanol/acetaldehyde conversion to 1,3-butadiene over a ZnO promoted ZrO2–SiO2 catalyst prepared by a sol–gel method was performed. The samples were characterized by N2 adsorption–desorption isotherms, scanning electron microscopy (SEM), NH3 temperature programmed desorption (NH3-TPD), X-ray powder diffraction characterization (XRD), thermogravimetric analyses (TGA), Fourier transform infrared resonance (FT-IR), 13C magic-angle spinning nuclear magnetic resonance (13C NMR) and X-ray photoelectron spectroscopy (XPS). The pore structure characteristics and surface acidity of Zn0.5–Zr–Si catalysts were largely decreased with time-on-stream and no crystal structure was formed in the used catalyst, indicating that the deactivation was caused by carbon deposition. Two main types of carbon deposition were formed, namely low-temperature carbon deposition with the oxidation temperature of around 400 °C and high-temperature carbon deposition with the oxidation temperature of 526 °C. The carbon species were mainly composed of graphitized carbon, amorphous carbon, carbon in C–O bonds and carbonyls. The deactivated catalyst could be regenerated by a simple oxidation process in air. Adding a certain amount of water into the feed had a positive effect on reducing the carbon deposition.
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高影响因子
MATERIALS & DESIGN
·
2018
·
IF 4.525
Xiaolei Li,Wei Wang,Qianli Li,Han Lin,Yue Xu,Lin Zhuang
Organosilane-functionalized carbon dots (SiCDs) immobilized silica composite nanoparticles (Fe 3 O 4 @SiO 2 @mSiO 2 -SiCDs) with dually emissive properties have been prepared by a modified sol-gel method. Such Fe 3 O 4 @SiO 2 @mSiO 2 -SiCDs nanoparticles solution exhibits blue light emission with a maximum wavelength of 470 nm at lower concentrations, and red-shifts to yellow-green light emission with maximum wavelength of 565 nm at higher concentrations, which is different with traditional carbon dots composite materials displaying strong emission only in the blue-light region. The SiCDs are immobilized in the outer mesoporous silica layer by covalent bonds via proper blending ration, which enables the nanoparticles solution to possess excellent fluorescence stability. The Fe 3 O 4 @SiO 2 @mSiO 2 -SiCDs nanoparticles show good stability, high surface area (483.19 m 2 /g), high saturation magnetization (22.1 emu/g) and low remanence (0.217 emu/g). When the concentration of nanoparticles solution is increased, the distance between the nanoparticles decreases and exhibits the concentration-mediated scattering phenomena, which result in the red-shift of fluorescent peaks. The specific structure of the Fe 3 O 4 @SiO 2 @mSiO 2 -SiCDs nanoparticles and the concentration-mediated scattering phenomena play key roles in the red-shift appearing.
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Inorganic Chemistry Frontiers
·
2018
·Vol. 5
·期 6
·1321-1328
·
IF 5.106
Wenting Li,Qi Liu,Rongrong Chen,Jing Yu,Hongsen Zhang,Jingyuan Liu,Rumin Li,Milin Zhang,Peili Liu,Jun Wang
Herein, we report on magnetic microspheres with numerous imine groups on the surface, which have great potential for U(VI) recovery in seawater. Hyperbranched polyethylenimine (HPEI) was covalently grafted onto the surface of the core–shell structured microspheres Fe3O4@SiO2. The microstructure and chemical composition of Fe3O4@SiO2-HPEI were comprehensively characterized. Consequently, the adsorption performance at low concentrations (3–30 μg L−1) under simulated seawater was investigated and the removal rate reached more than 90%. The superior performance of the Fe3O4@SiO2-HPEI is attributed to electrostatic force and chemical bonding (between amine/imine groups and U(VI)). We recommend, therefore, Fe3O4@SiO2-HPEI as a prospective alternative adsorbent in U(VI) recovery from seawater.
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ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Ebrahim Ataeivarjovi,Zhigang Tang,Jian Chen
In this present work, a novel approach has been proposed by which a solvent absorption and membrane desorption methods can significantly reduce the carbon dioxide (CO2) emission and energy consumption. In this method, the CO2 capture processing is based on the combination of membrane and physical solvent. Here, dimethyl carbonate and polydimethylsiloxane (PDMS)–SiO2 nanocomposite were used as the physical solvent and desorption membrane, respectively. However, the main focus of this research was on the CO2 desorption behavior of PDMS–SiO2 hybrid membrane. To do so, the influence of the operating conditions and membrane properties on the pervaporation process to capture CO2 have been investigated. The PDMS–SiO2 hybrid membrane containing 10 wt % SiO2 was the most effective membrane. Results revealed that increase in CO2 concentration from 1.5 to 3 wt % led to decrease in the selectivity from 94 to 47 and increase in flux from 1.7 to 5.38 (kg/m2·h). In addition, an increase in temperature increased the flux and reached the highest level (8.17 kg/m2·h) at 40 °C. However, the selectivity decreased to 36.13. It was found that the addition of SiO2 nanoparticles to the PDMS membrane not only enhanced the membrane performance but also decreased the energy consumption about 75% compared with gas stripping method and mass transfer about 49% compared with pure PDMS membrane. Finally, these results illustrated that such a novel technique used for pervaporation separation process is a green and promising alternative to separate CO2 from the physical solvent.
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ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Yiming Zhao,Lihua Zheng,Hao Wu,Huan Chen,Liwei Su,Lianbang Wang,Yuanhao Wang,Manman Ren
Tetravalent Si materials (SiO 2 and transition metal silicates) are receiving tremendous attentions for lithium storage, whereas a troublesome problem is how to improve the content of active Si. This work reports a novel method to boost their lithium storage capabilities by using highly-dispersed Co element in the form of nanofilm-like Co 2 SiO 4 /SiO 2 powder on the surface of reduced graphene oxide (RGO) that promotes the electronic diffusion and accommodates the volume changes. As a result, the Co 2 SiO 4 /SiO 2 /RGO exhibits over 20 times higher reversible capacity and better rate performance than the SiO 2 /RGO counterpart. In comparison, the Co 2 SiO 4 /SiO 2 /RGO shows the highest reversible capacity (1382 mAh g −1 at 500 mA g −1 ) and longest life span (500 cycles) in all known silicates-based materials and higher power/energy density than both of commercial graphite and Li 4 Ti 5 O 12 materials. Ex-situ X-ray photoelectron spectra and electrochemical tests at different voltage windows are conducted to illustrate the reason for the significantly improved performances. It demonstrates that tetravalent Si is gradually activated to lower-valence form by highly-dispersed Co generated with cycling. This observation provides new evidence for the electrochemical catalytic mechanism in transition metal silicates for lithium storage.
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Advanced Science
·
2019
·Vol. 6
·期 18
·1900943
·
IF 15.804
Pan Xue,Chuang Sun,Hongpeng Li,Jiajie Liang,Chao Lai
Lithium (Li) metal anodes have garnered increasing interest in recent years as its high theoretical capacity and low electrochemical potential promises a myriad of opportunities for various applications. However, one critical issue to overcome is the inhomogeneous deposition of Li + during the plating and stripping process. This inhomogeneous deposition could result in uncontrollable dendrite growth, further leading to poor coulombic efficiency, shorter lifecycles, and safety concerns due to internal short circuit and thermal runaways. To address these issues, a 3D porous core–shell fiber scaffold is presented, comprising of well-dispersed SiO 2 , TiO 2 , and carbon, as superlithiophilic host materials for lithium anodes. The amorphous SiO 2 and TiO 2 allow for controllable nucleation and deposition of metal Li inside the porous core–shell fiber even at ultrahigh current densities of 10 mA cm −2 . In addition, the interconnected conductive fiber with high porosity enables good electrical conductivity with fast ion transport and excellent mechanical strength to withstand massive Li loading during repeated cycles of stripping and plating. As a result, excellent cycling performance and high rate capability are observed in both symmetric cells and full cells, highlighting the feasibility of the proposed Li anode composite.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Dan-Lei Yang,Qian Sun,Yong-Hong Duan,Hao Niu,Rui-Li Wang,Dan Wang,Mei-Fang Zhu,Jie-Xin Wang
The size and structure of inorganic fillers have a significant effect on the mechanical properties of dental resin composites. In this work, we report the use of spray-drying for the efficient construction of SiO2 colloidal nanoparticle clusters (SCNCs) as novel dental fillers, yielding spherical and closely packed structures with diameters of 1–3 μm. The superior performance of the resin composites can be obtained by filling 70 wt % SCNCs assembled with 60 nm silica colloids as building blocks in the dental resin matrix. As compared to silica microparticles with a similar average size and primary monodispersed silica nanoparticles, SCNCs have a better strengthening effect on the mechanical properties of resin composites owing to their unique nano–micro secondary structures. This spray-drying strategy enables the construction of multicomponent fillers. This is very promising for the development of multifunctional high-performance restorative resin composites.
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危险品化学品经营许可证（带存储）