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81.
Changmei Sun Rongjun Qu Qiang Xu Chunnuan Ji Yanzhi Sun 《European Polymer Journal》2007,43(4):1501-1509
Two novel chelating resins were prepared by anchoring ethylenediamine to crosslinked polystyrene via a spacer containing sulfide. Their structures were characterized by Fourier transform-infrared spectra (FTIR) and scanning electron microscopy (SEM). Porous structure parameters of the resins were measured by ASAP 2020 using BET and BJH methods. Their adsorption capacities for several heavy metal ions especially Hg2+ were investigated. The results showed that for the two resins, the more N contents did not mean the better adsorption capacity and the saturated adsorption capacity of poly(2-ethylenediamidomercaptomethylstyrene) (PSM-EDA) for Hg2+ could reach to 3.0 mmol/g at room temperature. Isothermal adsorptions of the resins for Hg2+ could be described by Langmuir formula. The adsorption mechanism of the resins for Hg2+, Cu2+ and Ag+ was confirmed by X-ray photoelectron spectroscopy (XPS) and FTIR. 相似文献
82.
Using an on-line solution-reaction isoperibol calorimeter, the standard molar enthalpies of reaction for the general thermochemical reaction: LnCl3·6H2O(s) + 2C9H7NO(s) + CH3COONa(s) = Ln(C9H6NO)2(C2H3O2)(s) + NaCl(s) + 2HCl(g) + 6H2O(l) (Ln: Nd, Sm), were determined at T=298.15 K, as kJ mol−l, respectively. From the mentioned standard molar enthalpies of reaction and other auxiliary thermodynamic quantities, the standard molar enthalpies of formation of Ln(C9H6NO)2(C2H3O2)(s) (Ln: Nd, Sm), at T=298.15 K, have been derived to be: −(1494.7±3.3) and −(1501.5±3.4) kJ mol−l, respectively. 相似文献
83.
Fu L Wu NQ Yang JH Qu F Johnson DL Kung MC Kung HH Dravid VP 《The journal of physical chemistry. B》2005,109(9):3704-3706
Supported gold catalysts have drawn worldwide interest due to the novel properties and potential applications in industries. However, the origin of the catalytic activity in gold nanoparticles is still not well understood. In this study, time-of-flight secondary ion mass spectroscopy (TOF-SIMS) has been applied to investigate the nature of gold in Au (1.3 wt %)/gamma-Al2O3 and Au (2.8 wt %)/TiO2 catalysts prepared by the deposition-precipitation method. The SIMS spectrum of the supported gold catalysts presented AuO-, AuO2-, and AuOH- ion clusters. These measurements show direct evidence for oxidized gold on supported gold catalysts and may be helpful to gaining better understanding of the origin of the catalytic activity. 相似文献
84.
Z. H. Zhang Z. J. Ku H. R. Li Y. Liu S. S. Qu 《Journal of Thermal Analysis and Calorimetry》2005,79(1):169-173
The solid-state ternary complex of terbium chloride with L-tyrosine and glycine, [Tb(Tyr)(Gly)3Cl3·3H2O], was synthesized and characterized. Using a solution-reaction isoperibol calorimeter, the enthalpy of reaction for the following reaction, TbCl3·6H2O(s)+Tyr(s)+3Gly(s)=Tb(Tyr)(Gly)3Cl3·3H2O(s)+3H2O(l), was determined to be (5.1±0.6) kJ mol-1. The standard enthalpy of formation of Tb(Tyr)(Gly)3Cl3-3H2O at T=298.15 K has been derived as -(4267.3±2.3) kJ mol-1. The thermal decomposition kinetics of the complex was studied by non-isothermal thermogravimetry in the temperature range of 325-675 K. Two main mass loss stages existed in the process of the decomposition of the complex, the kinetic parameters for the second stage were analyzed by means of differential and integral methods, respectively. Comparing the results of differential and integral methods, mechanism functions of the thermal decomposition reaction for its second stage were proposed. The kinetic equation can be expressed as: d/dt=Aexp(-E/RT)(1-)2. The average values of the apparent activation energy E and pre-exponential factor A were 213.18 kJ mol-1 and 2.51·1020 s-1, respectively. 相似文献
85.
Yu H. G. Yu Dong J. X. Qin C. Q. Liu Y. Qu S. S. 《Journal of Thermal Analysis and Calorimetry》2004,75(3):807-813
The energy of combustion of crystalline 3,4,5-trimethoxybenzoic acid in oxygen at T=298.15 K was determined to be -4795.9±1.3 kJ mol-1 using combustion calorimetry. The derived standard molar enthalpies of formation of 3,4,5-trimethoxybenzoic acid in crystalline
and gaseous states at T=298.15 K, ΔfHm
Θ (cr) and ΔfHm
Θ (g), were -852.9±1.9 and -721.7±2.0 kJ mol-1, respectively. The reliability of the results obtained was commented upon and compared with literature values.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
86.
The reaction of Cu(I)(CH(3)CN)(4)BF(4) with 4-pyridylacrylic acid (4-HPYA) affords an unprecedented 8-fold interpenetrating diamondoid-like coordination polymer network [Cu(I)(3)(4-PYA)(2)(H(2)O)(BF(4)) ] (1) with a Cu(+)(4)(CO(2))(4) cluster as connecting node. The interpenetration in metal coordination polymers is the highest degree ever found within diamondoid nets containing a cluster as connecting note. Its fluorescent property was also reported. 相似文献
87.
Huifang Xu Wei Wei Chengliang Zhang Shujiang Ding Xiaozhong Qu Dr. Jiguang Liu Dr. Yunfeng Lu Prof. Zhenzhong Yang Prof. 《化学:亚洲杂志》2007,2(7):828-836
This report presents a facile approach for the low‐temperature synthesis of crystalline inorganic‐oxide composite hollow spheres by employing the bulk controlled synthesis of inorganic‐oxide nanocrystals with polymer spheres as templates. The sulfonated polystyrene gel layer can adsorb the target precursor and induce inorganic nanocrystals to grow on the template in situ. The crystalline phase and morphology of the composite shell is tunable. By simply adjusting the acidity of the titania sol, crystalline titania composite hollow spheres with tunable crystalline phases of anatase, rutile, or a mixture of both were achieved. The approach is general and has been extended to synthesize the representative perovskite oxide (barium and strontium titanate) composite hollow spheres. The traditional thermal treatment for crystallite transformation is not required, thus intact shells can be guaranteed. The combination of oxide properties such as high refractive index, high dielectric constant, and catalytic ability with the cavity of the hollow spheres is promising for applications such as opacifiers, photonic crystals, high‐κ‐gate dielectrics, and photocatalysis. 相似文献
88.
Changmei Sun Rongjun Qu Chunnuan Ji Chunhua Wang Guoxiang Cheng 《European Polymer Journal》2006,42(1):188-194
A novel chelating resin containing S, N and O atoms (PSME-EDA) was synthesized by using poly(2-hydroxyethylmercaptomethylstyrene) (PSME) and diethanolamine (EDA) as materials. Its structure was characterized by elemental analysis, Fourier transform-infrared spectra (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The adsorption of the resin for Hg2+ was investigated. The saturated adsorption capacity of PSME-EDA for Hg2+ could reach to about 1.1 mmol/g at 25 °C when the initial Hg2+ concentration was 0.02 mol/l. Some factors affecting the adsorption such as temperature, reaction time and ion concentration were also studied. The results showed that adsorption was controlled by liquid film diffusion. The increasing of temperature was beneficial to adsorption. The Langmuir model was better than the Freundlich model to describe the isothermal process. The values of ΔG, ΔH, and ΔS calculated at 25 °C were −7.99 kJ mol−1, 22.5 kJ mol−1 and 34.4 J mol−1 K−1, respectively. The adsorption mechanism of PSME-EDA resin for Hg(II) was confirmed by X-ray photoelectron spectroscopy (XPS). 相似文献
89.
This paper introducesa novel method for packing Capillary Electrochromatography Columns (CEC). Using vacuum packing methodology, silica particles as small as 1 microm were successfully packed into the capillary columns with 75 microm inner diameter. The columns are verystable and show no noticeable loss in efficiency after 200 sample injections. The performance of these vacuum packed capillary columns was evaluated with a mixture of aromatic and non-aromatic compounds. A 24 cm long capillary column can produce peak efficiencies of around 45,000 plates for benzene. 相似文献
90.
In this paper, cyclic voltammetry, linear sweep voltammetry and chronocoulometry in connection with the hang mercury drop electrode were used to study NiTMpyP and its mixture with DNA. The reduction of NiTMpyP in our experimental conditions involves in 4e reduction of TMpyP. NiTMpyP interacting with DNA forms electrochemically non-active complex DNA-2NiTMpyP, which can not be reduced on the Hg electrode. The peak potential of NiTMpyP does not shift and its electrochemical kinetic parameters indicate no significant change in the presence of DNA. However, the reduction current of NiTMpyP decreases obviously due to the formation of DNA-2NiTMpyP, which implies its equilibrium concentration decreases when DNA was mixed. The decrease of peak current is proportional to DNA concentration, which can be applied to estimate DNA concentration. 相似文献