Sorption Behavior and Mechanism of Indium（ Ⅲ ） onto Amino Methylene Phosphonic Acid Resin

The sorption behavior of amino methylene phosphonic acid resin (APAR) for In(III) was investigated. Experimental results show that In(III) adsorbed on APAR can be eluted with 2mol·L⁻¹ HCl. The apparent rate constant is k₂₉₈=1.50×10⁻⁵s⁻¹. The sorption behavior of APAR for In(III) obeys the Freundlich isotherm. The thermodynamic parameters of sorption, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of sorption (APAR) for In(III) are 24.1kJ·mol⁻¹, −35.1kJ·mol⁻¹ and 200J·mol⁻¹·K⁻¹, respectively. The coordination molar ratio of the functional group of APAR to In(III) is 2∶1. The sorption mechanism of APAR for In(III) was examined by IR spectrometry. XIONG Chun-hua: Born in 1959 0 This project was supported by Foundation of Zhejiang Provincial Education Bureau(No.20010677) and Lishui Science and Technology Bureau(No.2001012).     

Adsorption of Macroporous Phosphonic Acid Resin for Nickel

1Introduction Thesynthesischaracterizationandadsorptionproper tyofpolymericmaterialshavebeenresearchedinrecent years[110].Macroporousphosphonicacidresin[11](PAR)isanovelpolymericmaterialwhichcontainsafunctional groupof[PO(OH)2].Ithasalotofadvantagessuchas…     

Adsorption of D113 resin for dysprosium(III)

The adsorption behavior and mechanism of D113 resin for Dy(III) was investigated by using the method of resin adsorption. Experimental results show that the optimum medium pH of adsorption of D113 resin for Dy³⁺ is pH=6.00 in the HAc-NaAc medium. The static adsorption capacity of D113 resin for Dy³⁺ is 292.7 mg·g⁻¹. The optimum eluant is 0.5 mol·L⁻¹ HCl. The adsorption rate constant is k ₂₉₈=6.8×10⁻⁶s⁻¹. The apparent activation energy of D113 resin for Dy(III) is 14.79 kJ·mol⁻¹. The adsorption behavior of D113 resin for Dy(III) obeys the Freundlich isotherm. The adsorption parameters of thermodynamic are ΔH=14.48 kJ·mol⁻¹, ΔS=54.69 J·mol⁻¹·K⁻¹, ΔG=−1.82 kJ·mol⁻¹.The adsorption mechanism of D113 resin for Dy³⁺ was confirmed by chemical analysis and IR spectra. Funded by the Natural Science Foundation of Zhejiang Province (No.201027), Foundation of Zhejiang Provincial Education Bureau (No.20040551) and Zhoushan Science Technology Bureau (No.04114)     

Study on method and mechanism for simultaneous desulfurization and denitrification of flue gas based on the TiO2 photocatalysis

Based on the TiO₂ photocatalysis mechanism, a new method of simultaneous desulfurization and denitrification from flue gas was proposed. Preparation of TiO₂ photocatalyst, design of photocatalysis reactor and influencing factors for simultaneous removal of SO₂ and NO, and removal mechanism of SO₂ and NO were studied. After the optimal values of concentration of O₂ in flue gas, the relative humidity of flue gas and the irradiation time in the photocatalysis reactor were used, the efficiencies of removal for SO₂ and NO can be achieved above 98% and about 67%, respectively. According to the results of removal products analysis, the removal mechanism of SO₂ and NO based on TiO₂ photocatlysis can be put forward, namely, SO₂ was oxidized to SO₃ partly, the bulk of NO was oxidized to NO₂, and both were removed by resorbing finally.     

Nanocomposite films of V<Subscript>2</Subscript>O<Subscript>5</Subscript>−MoO<Subscript>3</Subscript> xerogel with poly ethylene oxide intercalation

Poly ethylene oxide (PEO)_x−V₂O₅−V₂O₅−MoO₃ (x=0, 0.5, 1) films were prepared by the sol-gel method. The synthesis and structure of the films were investigated by XRD, TG-DTA, FTIR, etc. The results show that V₂O₅−MoO₃ xerogel has a layered structure and its interlayer space increased from 1.3181 nm at x=0 to 1. 7898 nm at x=1 after the nanocomposite films were dried, and PEO in the interlayer changes the interface structure by forming hydrogen bonds with V=0 bands. CV measurement indicates that the intercalation of PEO improves insertion/extration properties of Li⁺ ions in the interlayer. ZHENG Jin-xia: Born in 1976 Funded by the National Natural Science Foundation of China (No. 50172036) and Natural Science Foundation of Hubei Province(No. 2001ABB083)     

The Thermal Decomposition Kinetics of Polysiloxane/Polymethylacrylate IPNs Materials

1Introduction Recently,anincreasingattentionhasbeenpaidtopolysiloxanebecausepolysiloxaneisthermallyresistantpolymerinhightemperaturewiththermalenduranceinoxidativeatmosphereupto300℃andmoreininertat mosphere.Thermoanalyticaltechniques,suchasthermo gravimetric(TG),differentialthermolgravimetric(DTG),anddifferentialscanningcalorimetry(DSC)havewidelybeenusedtocharacterizepolymericmaterials.Qingzeng Zhu[1]investigatedthethermaldecompositionofsilazanepolymerswiththermogravimetrymethodandindicat…     

Mechanism of flue gas simultaneous desulfurization and denitrification using the highly reactive absorbent

Using slurry mixed by fly ash and alkaline material, removal of SO2 in industrial waste gas had been reported in the 1970s, which was named the wet scrubbing[1]. Sincethen, there have been many reports about flue gas desulfurization using the reactive ab- sorbent prepared with flying ash. There are four kinds as follows: (1) Using slurry of fly ash as absorbent[2―4], which mainly utilize the property of fly ash for desulphurization, but the removal efficiency is not high. (2) Using fly ash a…     

Influence of thickness on the properties of solution-derived LiMn<Subscript>2</Subscript>O<Subscript>4</Subscript> thin films

LiMn₂O₄ thin films of different thickness were derived from solution deposition and heat treated by rapid thermal annealing. The phase identification and surface morphology were studied by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the films were examined by galvanostatic charge-discharge experiments and electrochemical impedance spectroscopy. LiMn₂O₄ thin films of different thickness derived from solution deposition and rapid thermal annealing are homogeneous and crack free with the grain size between 20 nm and 50 nm. The specific capacity of these films is between 42 and 47 μAh·cm²·μm⁻¹. The capacity decreases with the increase of discharge current density. The capacity loss per cycle increases from 0.012% to 0.16% after being cycled 50 times as the film thickness increases from 0.18 μm to 1.04 μm. The lithium diffusion coefficients of these films are in the same order of 10⁻¹¹ cm²·s⁻¹.     

Effect of Fe(III) impurity on the electrochemical performance of LiFePO<Subscript>4</Subscript> prepared by hydrothermal process

Lithium iron phosphate (LiFePO₄) was synthesized from LiOH, FeSO₄ and H₃PO₄ by a hydrothermal process at 180°C. The samples were characterized by X-ray diffraction, scanning electron microscopy and chemical analysis. Electrochemical performance of the samples was tested in terms of charge-discharge capacity and cycling behavior. The results indicated that Fe(III) impurity had obviously effect on the electrochemical properties of LiFePO₄, and the formation of Fe³⁺ was caused by the oxidation of Fe²⁺ in the dissolving and feeding processes accompanying the increase of pH value. It was found that the precipitation separation was effective in decreasing the content of Fe³⁺ in the solution of FeSO₄ and the sealed feeding was useful in preventing the conversion of Fe²⁺ to Fe³⁺. When the content of Fe³⁺ < 0.5 wt%, the hydrothermally synthesized LiFePO₄ calcined at 750°C with sucrose as carbon source exhibited an initial discharge capacity of 154.9 mAh·g⁻¹ at the rate of 0.1 C (1 C = 150 mA·g⁻¹) and the cycling retention rate could reach 98% after 50 cycles at room temperature.     

Chemical reaction of in-situ processing of NiAl/Al2O3 composite by using thermite reaction

NiAl/Al₂O₃ composite were synthesized by thermite reaction of nickel oxide and aluminum powder mixtures. The phase, the microstructure of the composite, as well as the thermite reaction mechanism, were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) combined with differential scanning calorimetry (DSC). The experimental results show that the thermite reaction leads to the interpenetrating network structure of NiAl/Al₂O₃ at 1223K for 60 min and the chemical reaction apparent activation energy is E_ap=166.960±13.496 kJ·mol⁻¹ in the NiO/Al system. Funded by the Younger Teacher Foundation of High School of Anhui Province (No. 2003jq158)     

Structure and dielectric properties of ZnO and Nb<Subscript>2</Subscript>O<Subscript>5</Subscript> doped BaO-TiO<Subscript>2</Subscript> system microwave ceramics

The microwave dielectric properties and microstructure of BaTi4.3ZnyO9.6＋y ＋0.02 mol% SnO2＋0.01 mol% MnCO3＋x mol% Nb2O5（x=0-0.05, y=0-0.08） system ceramics were studied as a function of the amount of ZnO and Nb2O5 doped. Addition of （y=0-0.05） ZnO and （x=0-0.025） Nb2O5 enhanced the reactivity and decreased the sintering temperature effectively. It also increased the dielectric constant ε r and quality factor Q（=1/tan 8） of the system due to the substitution of Ti^4＋ ions with incorporating Zn^2＋and Nb^5＋ ions, which was analyzed by the reaction ZnO＋Nb2O5＋ 3 TiTxTi →ZnTi＋ 2NbTi＋3TiO2. When the system doped with （y=0.05） ZnO and （x=0.025） Nb205 were sintered at 1 160 ℃ for 6 h, the εr. Qf0 value and rfwere 36.5, 42 000 GHz, and＋1.8 ppm/℃, respectively, at 5 GHz.     

Effect of matrix composition on physical properties of Al<Subscript>3</Subscript>CON in-situ reaction reinforced corundum composite

60% white corundum used for aggregate, 5% aluminium powder for fixed additions and 35% various additives for matrix were prepared for specimens 1#,2#,3#. They were mixed uniformly with the suitable resin as a binder and pressed under pressure of 315 ton forging press, then dried at 200℃ for 24 h. Effects of various additives on 1500 ℃×2 h creep properties of Al3CON reinforced corundum composite were researched. The experimenal results show that creep coefficients of specimens 1#,2#,3# at 1500 ℃×2 h are 1.4×10^- 4, -9.4×10^-4, -22.6×10^-4, respectively. Crushing strength of the slide plate added with suitable additive A after fired at 1500 ℃ ×3 h reaches to 225 MPa, the creep rate is positive all the time from 0% to 0.014% at 1500 ℃ for 2 h. The microstructure result analysis shows that reinforced phases of Al3CON fiber composite have been formed after fired with Al powder in coke at high temperatures for specimen 1#, and the strength of the composite is increased. The hot modulus of rupture is up to 59 MPa at 1400 ℃ and the RUL is obviously higher than that at 1700 ℃. Its service life is two times as that of Al2O3-C slide plate when used in the process of pouring steel. The mechanism of creep rate resistance of the composites can be discovered by means of SEM and EDAX analysis. It is concluded that the active Al3CON and Al2O3 multiphases that were formed by N2 in gas, C, Al and Al2O3 inside the matrix of the composites during in-situ reaction,which gives the composites outstanding creep rate resistance for the dense zone resuiting from Al3CON oxidation that inhibits contraction at the high temperature. Besides, the matrix will turn into the multiphase with high refractoriness, N content and its Al3CON reinforced fiber will further increase accordingly. In addition, Al3CON formed by Al2O3 and C, Al in the matrix with N2 in gas will inhibit the creep rate and also greatly improve the creep rate resistance of the composites.     

Study on the isothermal oxidation behavior in air of Ti3AlC2 sintered by hot pressing

The isothermal oxidation behavior at 900–1300°C for 20 h in air of bulk Ti₃AlC₂ with 2.8 wt% TiC sintered by means of hot pressing was investigated in the work. The isothermal oxidation behavior generally followed a parabolic rate law. The parabolic rate constants increased from 1.39×10⁻¹⁰ kg²·m⁻⁴·s⁻¹ at 900°C to 5.56×10⁻⁹ kg²·m⁻⁴·s⁻¹ at 1300°C. The calculated activation energy was 136.45 kJ/mol. It was demonstrated that Ti₃AlC₂ had excellent oxidation resistance due to the continuous, dense and adhesive protect scales consisted of a mass of α-Al₂O₃ and a little of TiO₂ and/or Al₂TiO₅. In principle, the oxide scale was grown by the inward diffusion of O²⁻ and the outward diffusion of Ti⁴⁺ and Al³⁺. The rapid outward diffusion of cations usually resulted in the formation of cracks, gaps, and holes.     

Upgrade and separation of Co from solution with low-grade Co

Ｆｉｎｅｌｉｎｎａｅｉｔｅ ,ｕｓｕａｌｌｙｗｉｔｈＣｏｃｏｎｔｅｎｔｆｒｏｍ0 .2 %ｔｏ 0 .3 % ,ｉｓｏｎｅｏｆｔｈｅｉｍｐｏｒｔａｎｔｍａｔｅｒｉａｌｓｕｓｅｄｔｏｕｐｇｒａｄｅＣｏｏｒｅｓ .Ｄｕｅｔｏｌｏｗ ｇｒａｄｅＣｏａｎｄｉｔｓｉｎｔｅｒｇｒｏｗｉｎｇｗｉｔｈｓｅｖｅｒａｌｍａｔｅｒｉａｌｓｓｕｃｈａｓＦｅ ,ＣｕａｎｄＮｉｅｔｃ .,ｉｔｓｕｐｇｒａｄｅａｎｄｓｅｐａｒａｔｉｏｎａｒｅｄｉｆｆｉｃｕｌｔ[1] .ＴｈｅｍｅｔｈｏｄｍａｉｎｌｙｕｓｅｄｉｎＣｈｉｎａａｎｄａｂｒｏａｄｉｓｔｏｒｏａｓ…     

Cyclic oxidation behaviors of MoSi<Subscript>2</Subscript> with different relative density

The influence of different relative density on the cyclic oxidation behaviors of MoSi2 at 1 273 K were studied. ＂Pesting＂ was not found in all MoSi2 materials after being oxidized for 480 h. All samples exhibited continuous mass gain during the oxidation process. The mass gains of MoSi2 with the lowest relative density （78.6%） and the highest relative density （94.8%） are increased by 8.15 mg·cm^-2 and 3.48 mg·cm^-2, respectively. The surface of the material with lower relative density formed a loose, porous and discontinuous oxidation scale, which accelerated oxygen diffusion and aggravated the oxidation process. However, a dense scale in the material with higher relative density is formed, which acts a diffusion barrier to the oxygen atoms penetrating into the matrix. The high temperature oxidation resistance of MoSi2 can be improved by increasing its relative density.     

Microstructure and Thermal Properties Analysis of （1-x）As2S3-x CdBr2 Glass System

The homogeneous glass sample for the ( 1 - x ) As2S3-xCdBr2, where x=0. 015,0. 035,0.05, was prepared by the conventional melt-quenched method. Amorphoas ( 1 - x ) As2S3-xCdBr2 alloys were determined by X-ray diffraction, thermal compreheasive analysis and Raman scattering. The glass transittion temperature (TR) deereases a bit with the addition of CdBr2 . Based on the experimental data, the microstrtucture is considered to be the discrete molecule species of AsBr3 and Cd - S atomic bonds or clusters are honigeneously dispersed in a disordered polymer network formed by AsS3 pyramids interlinked by sulfur bridges.     

Two-step synthesis of TiC<Subscript>0.7</Subscript>N<Subscript>0.3</Subscript>@WC-MoC<Subscript>2</Subscript> core-shell microspheres and fabrication of TiC<Subscript>0.7</Subscript>N<Subscript>0.3</Subscript>@WC-MoC<Subscript>2</Subscript>-based cermets by SPS

The precursor with TiC0.7N0.3@WO3-MO3 microspheres were prepared by a novel method from the WO3-MoO3 sol dipping. Subsequently, TiC0.7N0.3@WC-MoC2 core-shell structural microspheres were successfully obtained by carburizing the precursor at 900 °C in a flowing mixture of CH4 (20 ml·min-1) and H2 (200 ml·min-1) for 2 h. Then TiC0.7N0.3@WC-MoC2-15Co cermets were prepared utilizing the core-shell powders by spark plasma sintering (SPS). Powders of the precursors with TiC0.7N0.3@WO3-MO3 microspheres, TiC0.7N0.3@WC-MoC2 microspheres and TiC0.7N0.3@WC-MoC2-15Co cermets were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The obtained TiC0.7N0.3@WC-MoC2 microspheres have a dense WC-MoC2 coatings shell. The thickness of the shell could be easily controlled by adjusting the number of sol dipping cycles. It was found that the TiC0.7N0.3@WC-MoC2 microspheres were more beneficial to fabricate the "core-rim" structures by SPS.     

Phase structure and electrical properties of La<Subscript>2</Subscript>O<Subscript>3</Subscript>-doped BiInO<Subscript>3</Subscript>-PbTiO<Subscript>3</Subscript> ceramics with high curie temperature

The phase structure and electrical properties of pure and La2O3-doped Bi-InO3-PbTiO3 （BI-PT） ceramics were studied respectively. In （1 -x）BI-xPT （x=0.72-0.80） ceramics, the stability of tetragonal phase increased with increasing x, and pure perovskite structure was obtained for x=-0.80 ceramics. The phase transition temperature range was between 575 ℃ and 600 ℃ for x=0.72-0.80 ceramics, higher than that of PT （-490 ℃）. The c/a ratio almost linearly decreased with increasing La2O3 content in x-0.80 ceramics. It is believed that Pb^2＋ vacancies were formed by La^3＋ substituting Pb^2＋ in La2O3-doped BI-PT ceramics. Tc shifted to lower temperature by 30 ℃/mol% La2O3. The maximum dielectric constant 8557 around 559 ℃ was exhibited in 0.5mol%-doped BI-0.80PT ceramics. La2O3-doped ceramics could be poled resulting from decreasing of c/a ratio and improving of dielectric loss and resistivity. The maximum piezoelectric coefficient d33 was 12 pC/N for 2mol%-doped BI-0.80PT ceramics.     

Synthesis and electrochemical properties of Cr-doped Li<Subscript>3</Subscript>V<Subscript>2</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript> cathode materials for lithium-ion batteries

Cr-doped Li₃V₂(PO₄)₃ cathode materials Li₃V_2−x Cr _x (PO₄)₃ were prepared by a carbothermal reduction(CTR) process. The properties of the Cr-doped Li₃V₂(PO₄)₃ were investigated by X-ray diffraction (XRD), scanning electron microscopic (SEM), and electrochemical measurements. Results show that the Cr-doped Li₃V₂(PO₄)₃ has the same monoclinic structure as the undoped Li₃V₂(PO₄)₃, and the particle size of Cr-doped Li₃V₂(PO₄)₃ is smaller than that of the undoped Li₃V₂(PO₄)₃ and the smallest particle size is only about 1 μm. The Cr-doped Li₃V₂(PO₄)₃ samples were investigated on the Li extraction/insertion performances through charge/discharge, cyclic voltammogram (CV), and electrochemical impedance spectra(EIS). The optimal doping content of Cr was that x=0.04 in the Li₃V_2−x Cr _x (PO₄)₃ samples to achieve high discharge capacity and good cyclic stability. The electrode reaction reversibility was enhanced, and the charge transfer resistance was decreased through the Cr-doping. The improved electrochemical performances of the Cr-doped Li₃V₂(PO₄)₃ cathode materials are attributed to the addition of Cr³⁺ ion by stabilizing the monoclinic structure. Funded by the Guangxi Natural Science Foundation(No. 0832259) and the National Basic Research Program of China (No. 2007CB613607)     

Structure and Electric Properties of （1-x）（Bi1/2Na1/2） TiO3-xBaTiO3 Systems

The structural, dielectric and piezoelectric properties of （1-x）（Bi1/2Na1/2） TiO3-xBaTiO3 ceramics were investigated for the compositional range, x=0.02, 0.04, 0.06, 0.08, 0.10. The samples were synthesized by a conventional solid-state reaction technique. All compositions show a single perovskite structure, and X-ray powder diffraction patterns can be indexed using a rhombohedral structure. Lattice constants and lattice distortion increase while the amount of BaTiO3 increases. The X-ray diffraction results show the morphotropic phase boundary （MPB） of （1-x）（Bi1/2Na12） TiO3-xBaTiO3 exists in near x=0.06-0.08. Temperature dependence of dielectric constant eT33/ε0 measurement reveals that all compositions experience one structural phase and two ferroelectric phases transition below 400℃： rhombohedral （or rhombohedral plus tetragonal） ferroelectric phase ←→ tetragonal antiferroelectric phase ←→ tetragonal paraelectric phase. Relaxor behaviors exist in the course of ferroelectric to antiferroelectric phase transition. Dielectric and piezoelectric properties are enhanced in the MPB range for （ 1-x）（Bi1/2Na1/2）TiO3-xBaTiO3.