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Su J.,Fujian Normal University | Huang H.-G.,Xiamen Zijin Mining and Metallurgy Technology Co. | Jin X.-Y.,Fujian Normal University | Lu X.-Q.,Washington State University | Chen Z.-L.,Fujian Normal University
Journal of Hazardous Materials | Year: 2011

In this study, organobentonites were prepared by modification of bentonite with various cationic surfactants, and were used to remove As(V) and As(III) from aqueous solution. The results showed that the adsorption capacities of bentonite modified with octadecyl benzyl dimethyl ammonium (SMB3) were 0.288mg/g for As(V) and 0.102mg/g for As(III), which were much higher compared to 0.043 and 0.036mg/g of un-modified bentonite (UB). The adsorption kinetics were fitted well with the pseudo-second-order model with rate constants of 46.7×10-3g/mgh for As(V) and 3.1×10-3g/mgh for As(III), respectively. The maximum adsorption capacity of As(V) derived from the Langmuir equation reached as high as 1.48mg/g, while the maximum adsorption capacity of As(III) was 0.82mg/g. The adsorption of As(V) and As(III) was strongly dependent on solution pH. Addition of anions did not impact on As(III) adsorption, while they clearly suppressed adsorption of As(V). In addition, this study also showed that desorbed rates were 74.61% for As(V) and 30.32% for As(III), respectively, after regeneration of SMB3 in 0.1M HCl solution. Furthermore, in order to interpret the proposed absorption mechanism, both SMB3 and UB were extensively characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses. © 2010 Elsevier B.V.

PubMed | University of Saskatchewan, Shanghai University, Xiamen Zijin Mining and Metallurgy Technology Co Ltd. and Xiamen University
Type: Journal Article | Journal: Inorganic chemistry | Year: 2015

The tailor effect of fluoride, exclusively as a terminal rather than a bridge, was applied successfully to design low-dimensional structures in the system of transition metal germanophosphates for the first time. Two series of new compounds with low-dimensional structures are reported herein. K[M(II)Ge(OH)2(H0.5PO4)2] (M = Fe, Co) possess flat layered structures built from single chains of edge-sharing M(II)O6 and GeO6 octahedra interconnected by HPO4 tetrahedra. Their fluorinated derivatives, K4[M(II)Ge2F2(OH)2(PO4)2(HPO4)2]2H2O (M = Fe, Co), exhibit band structures of two four-membered ring germanium phosphate single chains sandwiched by M(II)O6 octahedra via corner-sharing. Both of these structures contain anionic chains of the condensation of four-membered rings built from alternating GeO42 ( = F, OH) octahedra and PO4 tetrahedra via sharing common GeO42 ( = F, OH) octahedra, the topology of which is the same as that of the mineral krhnkite [Na2Cu(SO4)22H2O]. Note that the switch from the two-dimensional layered structure to the one-dimensional band structure was performed simply by the addition of a small amount of KF2H2O to the reaction mixture. This structural alteration arises from the incorporation of one terminal F atom to the coordination sphere of Ge, which breaks the linkage between the transition metal and germanium octahedra in the layer to form the band structure.

Hu X.,Xiamen University | Guo Y.,Xiamen University | Guo Y.,Xiamen Zijin Mining and Metallurgy Technology Co. | Wang L.,Xiamen University | And 3 more authors.
Journal of Supercritical Fluids | Year: 2011

A supercritical fluid-based method is proposed to produce coenzyme Q 10 (CoQ10) nanoparticles. First, CoQ10/ polyethylene glycol 6000 composite particles are prepared by a modified PGSS (particles from gas-saturated solutions) process with controlling the flow rate of the gas-saturated solution. Then, CoQ10 nanoparticles are obtained by dissolving the composite particles into water. The effect of experimental variables of the modified PGSS process, including pressure, temperature, flow rate of the gas-saturated solution, and mass fraction of CoQ10, on the CoQ10 particle size and particle size distribution was investigated. Results show that CoQ10 slurry product with a median diameter of 190 nm and yield of 89.8% can be prepared at an optimum condition (operating pressure of 25 MPa, operating temperature of 80 °C, gas-saturated solution flow rate of 1.02 mL/min, CoQ10 mass fraction of 40% and nozzle diameter of 100 μm) via the supercritical fluid-based method. © 2011 Elsevier B.V. All rights reserved.

Zhuang R.-C.,Xiamen University | Zhuang R.-C.,Xiamen Zijin Mining and Metallurgy Technology Co. | Yang J.,Xiamen University | Wang D.-Y.,IMDEA Madrid Institute for Advanced Studies | Huang Y.-X.,Xiamen University
RSC Advances | Year: 2015

Organic/inorganic intercalated dodecyl-ammonium dihydrogen-phosphate (C12ADP) has been prepared by a simple one-pot method. The incorporation of C12ADP into epoxy could improve the flame retardancy and toughness of the obtained C12ADP/EP composites, simultaneously, i.e. improved formed char quality, significantly reduced heat release rate and decreased total heat release, and enhanced impact toughness of EP composites as well. © 2015 The Royal Society of Chemistry.

Huang Y.-X.,Xiamen University | Liu B.,Xiamen University | Wen L.,Xiamen University | Zhang X.,Xiamen University | And 6 more authors.
Inorganic Chemistry | Year: 2013

Structural assembly from phosphate to germanophosphate by applying germanate as a binder has been achieved. Two isotypic porous compounds, K 3[MII 4(HPO4)2][Ge 2O(OH)(PO4)4]·xH2O (M II = Fe, Cd; x = 2 for Fe and 3 for Cd, denoted as KFeGePO-1 and KCdGePO-1, respectively), contain a known transition-metal phosphate (TMPO) layer, ∞2{[M2(HPO4)3] 2-}, which is built from chains of trans-edge-sharing MO6 octahedra bridged by MO5 trigonal bipyramids that were further linked and decorated by phosphate tetrahedra. The layers are bound by infinite chains of GeO5(OH) octahedra, resulting in a 3D open-framework structure with 1D 12-ring channels that are occupied by K+ ions and water molecules. The curvature of the TMPO layers and shape of the 12-ring windows can be tuned by the transition metals because of their Jahn-Teller effect. © 2013 American Chemical Society.

PubMed | University of Saskatchewan, Xiamen Zijin Mining and Metallurgy Technology Co Ltd and Xiamen University
Type: Journal Article | Journal: Inorganic chemistry | Year: 2016

Anhydrous compounds are crucially important for many technological applications, such as achieving high performance in lithium/sodium cells, but are often challenging to synthesize under hydrothermal conditions. Herein we report that a modified solvo-/hydro-fluorothermal method with fluoride-rich and water-deficient condition is highly effective for synthesizing anhydrous compounds by the replacement of hydroxyl groups and water molecules with fluorine. Two anhydrous phosphate germanium fluorides, namely, Na

Zhang N.,Xiamen Zijin Mining and Metallurgy Technology Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2011

A determination method of silicon dioxide in copper concentrate and lead concentrate by inductively coupled plasma atomic emission spectrometry (ICP-AES) was developed. The sample was melted at high temperature in corundum crucible using sodium peroxide as flux. The fusion cake was leached with hot water and acidified with hydrochloric acid. After matrix dilution, the internal standard element Au was added. The effects of matrix and instrumental fluctuation could be effectively eliminated using internal standard calibration method. The detection limit of silicon dioxide in this method was 0.0063 μg/mL, and the determination range (mass fraction) was 0.02%-10%. The proposed method had been applied to the determination of certified reference materials of copper concentrate and lead concentrate. The determination results were in good agreement with the certified values, and the RSD(n=5) was less than 3%.

Zhang N.,Xiamen Zijin Mining and Metallurgy Technology Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2010

The ore sample was treated by alkali fusion and acidification, and tungsten and molybdenum were then simultaneously determined by inductively coupled plasma atomic emission spectrometry(ICP-AES). The interference of matrix sodium introduced during sample fusion to testing elements was investigated. The results showed that the matrix effect was obvious, and it was aggravate with the increase of sodium concentration. The instrumental stability was then seriously reduced, influencing the accuracy of determination results. By selecting optimal excitation conditions and proper analytical lines, the interference of matrix elements(sodium, iron, calcium and aluminum) contained in sample or introduced in sample fusion process could be eliminated by dilution. The detection limits for tungsten and molybdenum were 0.010 μg/mL and 0.004 μg/mL, respectively. The limit of detection for tungsten and molybdenum were 0.03%-6% and 0.01%-6%, respectively. The proposed method was applied to the determination of ore standard sample, and the results were consistent with the certified values. The relative standard deviations(RSD) were 0.78%-2.7%.

Huang H.,Xiamen Zijin Mining and Metallurgy Technology Co.
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2015

Incorporating multi-functional nano-particles into natural fiber reinforced polymer composites can provide with the multi-functionality, making them possess sensor performance, which are capable of in-situ sensing the change of surrounding environment. However, it is realized by dispersing nano-particle into matrix, which normally leads to high viscosity of matrix, hindering its application and meanwhile high nano-particle loadings are needed to reach percolation threshold. Dip coating technology was used for the surface modification of sisal fibres (SF) with multi-walled carbon nanotubes (MWCNTs) dispersion as dye, the resulting MWCNTs modified sisal fibers (MWCNTs-SF) and their epoxy based composite (MWCNTs-SF/EP) sensors were prepared. A continuous and homogenous dispersed MWCNTs network coating forms on surface of MWCNTs-SF. The current versus voltage characteristic curve of MWCNTs-SF indicates the formation of ohmic contacts for MWCNTs-MWCNTs and MWCNTs-electrode. Both MWCNT-SF and MWCNTs-SF/EP are characterized by negative temperature coefficient thermistor. Under external strain-stress, the electrical resistance of MWCNTs-SF and MWCNTs-SF/EP exhibits nearly constant at very low strains, then increases linearly at intermediate strains, while an exponential correlation between electrical resistance and strain exists at higher strains. The different sensing characteristics for MWCNTs-SF and MWCNTs-SF/EP mostly relate to the MWCNTs network structure change during consolidation. The tensile strength of MWCNTs modified sisal fiber fabric reinforced epoxy based composite increases gradually from 37.6 MPa to 46.7 MPa with increasing surface modification time, elastic modulus also increases accordingly. ©, 2015, Beijing University of Aeronautics and Astronautics (BUAA). All right reserved.

Zhang J.,Leibniz Institute of Polymer Research | Zhang J.,Xi'an Jiaotong University | Zhuang R.,Xiamen Zijin Mining and Metallurgy Technology Co. | Liu J.,Leibniz Institute of Polymer Research | And 4 more authors.
Soft Materials | Year: 2014

Electrophoretic deposition (EPD) is used to deposit multiwalled carbon nanotube networks (CNTs) onto electrically insulating glass fiber surfaces. We found that the thin networks on a single glass fiber surface exhibit semiconducting properties. This enables us to realize a single CNT-glass fiber as a probe with novel multifunctional capabilities for in-situ monitoring of various chemical/physical transitions, particularly in the interphase region between polymer and glass fiber. Because of the intimate interaction between CNTs and polymers in the vicinity of a glass fiber, our CNT probe can rapidly sense the local changes of fundamental polymer properties, such as glass transition, reaction activation energy, cross-linking reaction, and crystallization. © Taylor & Francis Group, LLC.

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