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Yin Q.,East China Institute of Technology | Yin Q.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Chen Q.,East China Institute of Technology | Liu Y.,East China Institute of Technology | And 3 more authors.
International Journal of Electrochemical Science | Year: 2011

In this work, a novel and sensitive spectrometric method for determination of copper was developed with carbon nanotubes (CNTs) as a toner. The optimum operating conditions regarding kind of CNTs, concentration of reagents and pH were established. The enhancing mechanism of CNTs was also investigated. Comparative experiments prove that the application of carboxyl CNTs has the optimum hyperchromic effect: the absorbance of the complex was increased by nearly 100% through optimizing the technological parameters. The coloration system showed maximum absorbance at 578nm with a molar absorptivity value of 2.75×105 l mol-1 cm-1; the calibration graph was linear over the range 0.1-11.0μg/25.0ml and the limit of detection was 158ng/25ml. The enhancing mechanism of CNTs is that the copper-PF complex can be closely absorbed onto the sidewall of CNTs to form a novel and structural stable complex, which can reduce the adverse effects caused by the hydrolysis reaction of copper, and improve the sensitivity of the coloration system. © 2011 by ESG.


Yin Q.,East China Institute of Technology | Yin Q.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Chen R.,East China Institute of Technology | Liu Y.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology
International Journal of Electrochemical Science | Year: 2011

A novel and sensitive spectrometric method for determination of lead was developed with the application of carboxylic carbon nanotubes (CNTs) and cetyltrimethyl ammoniumbromide (CTMAB). The optimum operating conditions regarding pH, volume and addition order of reagents solution were established. The nature of the complex was also investigated. Comparative experiments proved that the application of carboxyl CNTs and CTMAB had the obvious hyperchromic effect: the absorbance of the complex was increased by nearly 90% through optimizing the technological parameters. The coloration system showed the maximum absorbance at 600.4nm with a molar absorptivity value of 0.70×10 5 L mol -1 cm -1; the calibration graph was linear over the range 0.5.11.0μg/25.0mL and the limit of detection was 17.8ng/mL. Moreover, the method is easy and direct to perform for the determination of lead. © 2011 by ESG.


Zhao J.,Qingdao Technological University | Zhao J.,Fudan University | Zhao J.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Yu H.,Qingdao Technological University | And 8 more authors.
Journal of Physical Chemistry C | Year: 2014

The production of effective loading and direct deposition of Pt nanoparticles on graphene is difficult because this intriguing carbon material has highly hydrophobic surface properties. In this work, Pt/graphene sheet (GS) composites were successfully synthesized via a simple, effective, and environmentally benign one-pot supercritical carbon dioxide deposition route using dimethyl (1,5-cyclooctadiene) platinum(II) (PtMe2COD) as a soluble organometallic precursor. The preparation process obviates the need for solvents, which are often volatile and toxic. No post-treatment processes such as washing and drying are needed. Transmission electron microscopy shows that ultrafine metal nanoparticles with an average size as small as ∼2 nm are densely and evenly decorated on the hydrophobic surfaces of GS at Pt loadings up to 80 wt %. Electrochemical studies reveal that the prepared Pt/GS composites possess notably higher catalytic activity and better stability toward methanol electrooxidation in comparison with Pt/multiwalled carbon nanotube and Pt/carbon black composites. The supercritical carbon dioxide deposition method could be easily extended to the fabrication of other graphene-based metal composites with desirable properties by selecting suitable organometallic precursors. © 2014 American Chemical Society.


Han Z.-X.,Huaihai Institute of Technology | Han Z.-X.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Han Z.-X.,Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection | Zhu Z.,Huaihai Institute of Technology | And 3 more authors.
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2014

Natural sepiolite was used as an adsorbent for the investigation of the adsorption kinetics, isotherms, thermodynamic parameters of an acid blue 25 (AB25), methylene blue (MB) from aqueous solution at various pHs, temperatures, the kinetics, and thermodynamics for the removal of the two dyes onto natural sepiolite have also been investigated. The adsorbed amounts of AB25 increased with decreasing pH and the optimum pH value for the AB25 and MB were found to be 3.0 and 9.0. respectively. The adsorption capacity of AB25 onto natural sepiolite increased with the increasing temperature, indicating that AB25 and MB dye adsorption on the natural sepiolite was an endothermic process, the second-order model is found to be more suitable to describe the adsorption kinetic data than the first-order model for natural sepiolite on the AB25 and MB and the adsorption process of AB25 and MB are showing pseudo-second-order kinetic behavior, respectively. The adsorption of AB25 and MB on natural sepiolite may be followed by an intraparticle diffusion up to 60 and 90 min, respectively, and the Langmuir equation represents the adsorption process better. The fit of the data for AB25 and MB adsorption onto natural sepiolite suggests that the D-R model gave slightly closer fittings than those of Langmuir and Freundlich models. The adsorption of AB25 on natural sepiolite has a low potential barrier, which is also indicates a physical adsorption. The negative values of G0 and positive H0 which has been obtained indicates that the MB adsorption process is a spontaneous and endothermic. Copyright © Taylor &Francis Group, LLC.


Han Z.X.,Huaihai Institute of Technology | Han Z.X.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Han Z.X.,Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection | Wu D.-D.,Huaihai Institute of Technology | And 3 more authors.
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2014

The anthropogenic release of carbon dioxide into the atmosphere leads to an increase in the CO2 partial pressure in the ocean, which may reach 950 ?atm by the end of the 21st century. An experiment was performed to test the effects of increased sea water concentrations of CO2 combined with heavy metals on mortality rates, metallothionein, immune funtion, and uptake kinetics of the bivalve Mytilus edulis L. As a result, the mortality rates of Mytilus edulis L fluctuated with pH variety in all heavy metals (Cd, Pb, Cu) test seawater treatments compared to control group. It was demonstrated that in vivo Cd-, Pb-, or Cu pretreatment under acidifications can alleviate metallothionein by in vitro Cd, Pb, and Cu in soft tissues and suggested that acidification can aggravate heavy metals pollution and toxicity for marine organisms. Moreover, the fraction of eosinophilic cells increased over the 21 days period for Cd exposure, then decreased with 28 and 35 days incubation, the fraction of eosinophilic cells increased similar with Cd exposure and pH 8.2. The fraction of eosinophilic cells significantly increased from 32% to 53% of the hemocyte population over the 35-day period for Pb exposure and pH8.2, the fraction of eosinophilic cells increased from 35% to 58% of the hemocyte population over the 35-day period for Pb exposure and pH 6.2. Phagocytosis levels declined with increasing exposure time for Cd alone and phagocytosis levels declined with decreasing pH (from 8.2 to 6.2) with Cd exposure on 35 days. Mytilus edulis L in Pb with reduced pH (6.2) treatments also decreased their phagocytosis levels on 35 days. Further, phagocytosis decreased bigger than that of Pb with pH 8.2. At steady state equilibrium, CF of 109Cd was significantly higher at pH 6.2 and pH 7.7 than at pH 8.2, the accumulation of 203Pb was significantly higher at the lowest pH 6.2 level than at the two exposure levels (pH 7.7 and pH 8.2). Similarly, the lower the seawater pH 6.2, the more 63Cu was accumulated in the hemolymph of Mytilus edulis L. The results indicate that future reductions in pH caused by increased CO2 concentrations in the sea may have an impact on Mytilus edulis L combined with heavy metals pollution. Copyright © Taylor & Francis Group, LLC.


Li Z.,Chongqing University of Arts and Sciences | Li Z.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Zhao H.,Chongqing University of Arts and Sciences
EPL | Year: 2015

We investigate the spatial Bloch-like oscillations in planar double-period silver waveguide arrays. Three types of oscillation modes are obtained in the sixth-generation double-period structure at different incident position, namely positive oscillation mode, negative oscillation mode and breathing-wave-like oscillation mode. The period of the three types of oscillation modes increases when the incident wavelength is redshifted, while the period of the up-oscillation and down-oscillation of the breathing-wave-like oscillation mode decreases and increases, respectively, in the gradient sixth-generation double-period system. © EPLA, 2015.


Zhao J.,Qingdao University of Science and Technology | Zhao J.,Hangzhou Normal University | Zhao J.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Zhang L.,Qingdao University of Science and Technology | And 11 more authors.
RSC Advances | Year: 2012

An effective, simple, low temperature and environmentally benign supercritical fluid (SCF) route is presented for preparing graphene-supported metal nanoparticles. With the assistance of supercritical carbon dioxide (SC CO 2), ultrafine PtRu nanoparticles with an average size of 2.87 nm were very uniformly distributed on the surfaces of functionalized graphene sheets (FGSs) by the reduction of a mixture of H 2PtCl 6 and RuCl 3 precursors. The catalytic property of the as-prepared composites for methanol oxidation was investigated by cyclic voltammetry and chronoamperometry. In comparison with their carbon black (Vulcan XC-72) counterparts, the PtRu/FGSs composites showed considerably improved catalytic activity and stability for methanol oxidation. The high surface area of graphene and even distribution of ultrafine bimetallic particles are vital for the superior electrocatalytic performance of the PtRu/FGSs composites. The findings suggest that highly efficient graphene-supported metallic electrocatalysts can be fabricated by the supercritical fluid method and graphene as a favorable electrocatalytic carrier, which has promising potential application in direct methanol fuel cells. © The Royal Society of Chemistry. 2012.


Ge Y.,Qufu Normal University | Ge Y.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Lu K.S.,Qufu Normal University | Su X.Y.,Qufu Normal University
Advanced Materials Research | Year: 2013

These stable self-assembled nanoparticles were characterized by dynamic light scattering, transmission electron microscopy, and atomic force microscopy, which demonstrated that the nanosystem consists of spherical particles with a smooth surface both in aqueous environment and in dried state. Toxicity measurements showed that the composition is nontoxic when tested either on cell cultures or in animal feeding experiments. To evaluate the potential of the nanosystem for intracellular drug delivery and gene, the nanoparticles were fluorescently labeled and folic acid was attached as a cancer cell-specific targeting moiety. The quantitative data obtained by digital processing of the intensity of green color of each pixel in the pictures inside the cell boundaries and total intensity of fluorescence inside the cells showed that "targeted" particles internalized into the cells significantly faster and the total accumulation of these particles was substantially higher in the cancer cells. © (2013) Trans Tech Publications, Switzerland.


Zhao X.Y.,Chongqing University of Arts and Sciences | Lei X.W.,Chongqing University of Arts and Sciences | Lei X.W.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology
Indian Journal of Physics | Year: 2012

Critical behavior of the two-dimensional fully frustrated XY model has been investigated with Monte Carlo methods. Based on the dynamic scaling ansatz of the magnetization for temperatures above the transition temperature, the correlating time, spatial correlation length has been extracted. Fitting the correlation length to the exponential singularity assumed for the Kosterlitz-Thouless (KT) transition, the transition temperature T KT and the static exponent m have been determined. The T KT = 0.45065(3) is one percent or two higher than that estimated from simulations in equilibrium. Moreover, the exponent m = 0.089(2) is smaller than the theoretical value 0.5. © 2012 IACS.


Yang G.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology | Yang G.,Qufu Normal University | Lu K.S.,Qufu Normal University | Su X.Y.,Chongqing Key Laboratory of Micro Nano Materials Engineering and Technology
Advanced Materials Research | Year: 2014

The present paper describes the preparation and characterization of novel biodegradable nanoparticles based on self-assembly of poly-γ-glutamic acid (γ-PGA). The nanosystems were stable inaqueous media at low pH conditions. Solubility of the systems was determined by turbidity measurements. Surface charge and mobility were measured electrophoretically. It was found that the size and size distribution of the nanosystems depends on the concentrations of γ-PGA solutions and their ratio as well as on the pH of the mixture and the order of addition. The average hydrodynamic diameters were between 150 and 330 nm. These biodegradable,self-assembling stable nanocomplexes might be useful for several biomedical applications. © (2014) Trans Tech Publications, Switzerland.

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