1-(Pyridin-2-yl) Imine Functionalized Silica Gel: Synthesis,Characterization, and Preliminary Use in Metal Ion Extraction

A new silica gel material covalently bonded with 1-(pyridin-2-yl) imine (SiNPn) was synthesized and well characterized by elemental analysis, FT–IR, ¹³C NMR of the solid state, nitrogen adsorption-desorption isotherm, BET surface area, B.J.H. Pore sizes, thermogravimetry curves (TGA), and scanning electron microscope (SEM). The new chelating surface exhibits good chemical and thermal stability. The adsorption capabilities of this new system towards toxic metal ions (Hg²⁺, Cd²⁺, Pb²⁺, and Zn²⁺) were investigated using the batch method. The percentage limits of extraction were determined by atomic absorption measurements.     

Adsorption Behavior of Cd (II) from Aqueous Solution using Dialdehyde 5-Aminophenanthroline Starch

Dialdehyde 5-aminophenanthroline starch (DASAPL) was synthesized by reacting 5-aminophenanthroline with dialdehyde starch, and it was characterized through elemental analysis, FT-IR, and SEM techniques. FT-IR of DASAPL revealed the incorporation of C?N group and the disappearance of the C?O (carbonyl) group. DASAPL was used to adsorb Cd (II) from aqueous solution. The adsorption process was optimized with regard to pH, contact time, initial Cd (II) concentration, and temperature. The results revealed that the initial pH 5 and contact time of 2 h were the optimal conditions. The material showed good adsorption capacity and the adsorption data followed the Freundlich and Langmuir model. The adsorption of Cd (II) decreased with increasing temperature indicating exothermic nature of the adsorption process. Thermodynamic studies have been used to determine thermodynamic parameters of the process including Gibbs free energy, enthalpy, and entropy changes. Moreover, the adsorbents can be reused.     

镉电极结构改进对电池快充性能的影响

搞电极表面积的大小是影响其氧复合性能的重要因素之一。本实验通过对偏电极的结构进行改进，提高了铝电极的氧复合的有效表面积，改善了电池的快充性能及其密封性能。     

The effect of Co addition on the positive active material in Ni–Cd pocket-plate batteries

The nickel electrodes in Ni–Cd pocket-plate batteries have been cobalt-doped (0.8–5.0 wt.%) either by coprecipitation during Ni(OH)₂ fabrication or by addition of cobalt oxide. It was observed that both methods of doping significantly improved the initial performance and performance after accelerated testing. In general, the higher the cobalt content, the higher the degree of material utilisation.     

Electrocatalytic oxidation of sodium borohydride on metal ad-atom modified Au(111) single crystal electrodes in alkaline solution

The electrochemical oxidation of borohydride was investigated by using various ad-atom modified Au(111) electrodes in alkaline media in comparison to Au(111) single crystal, polycrystalline Au, Pt and Zn electrodes. The catalytic activity of gold towards borohydride oxidation has tended to increase in more alkaline media as reflected in the oxidation peak in the concentration range of NaOH (0.01-2.0 M) studied. Additional shift on the oxidation peak potential of borohydride on Pt and Zn ad-atom modified Au(111) electrodes was observed for both ad-atom modified electrodes to more negative potentials compared to that of bare electrodes, respectively. The ad-atom modified Au(111) electrodes surfaces do not only provide a superior electrical contact, but also accelerates electron transfer as proven by the increase in peak current and positive shift in the peak potential.     

The direct determination of the vacancy concentration andP-T phase diagram of Hg0.8Cd0.2Te and Hg0.6Cd0.4Te by dynamic mass-loss measurements

A modified mass-loss measurement technique is employed, for the direct,in- situ determination of the metal vacancy formation in (Hg_1x2212;itxCd _x )_1−y Te _y (s) withx = 0.2 and 0.4. Forx = 0.2, the metal vacancy concentrations are determined between 336 and 660° C for three different compositions(y) within the homogeneity region and range from 2.4 to6.8 x 10¹⁹cm₋₃. The enthalpy of formation of a singly-ionized metal vacancy is derived to be between 0.17 and 0.45 eV depending upon the deviation from stoichiometry (compositiony). Forx= 0.4, three samples of different y-values give the metal vacancy concentrations from 1.9 to 5.5 x 10¹⁹cm⁻³ between 316 and 649° C, and the enthalpy of vacancy formation between 0.25 and 0.40 eV. Compared to the recent data on HgTe(s), these experimental results show a slight but significant decrease in the enthalpy of vacancy formation from HgTe to Hg_0.8Cd_0.2Te, which supports theoretical predictions of the bond weakening effect of Cd for the latter alloy system. Based on the simultaneously determined equilibrium Hg partial pressures within the homogeneity range, the vacancy concentration-partial pressure isotherms are constructed. The Hg partial pressures are also measured along the three-phase boundaries of the solid solutions of bothx = 0.2 and 0.4, and these are in close agreement with published data obtained by optical absorption measurements.     

土壤固相组分对镉吸持试验研究

选用三种不同类型的土壤，用连续提取法去除土壤固相中碳酸盐（石灰性土壤）、氧化锰、有机质、无定型氧化铁和晶型氧化铁组分，制得分离某一组分或某几个组分后土壤钙饱和的样品，研究土壤固相各组分对Ｃｄ吸持的影响。研究表明，Ｃｄ的吸持能力除受土壤理化性质的影响外，土壤固相组分及其相互作用直接控制着土壤对重金属Ｃｄ的吸持。     

铁基体改进效应在石墨炉原子吸收法测定痕量镉中的应用

用石墨炉原子吸收分光光度法测定环境废水中的痕量Cd时,Mn、Cr、Ni、Cu、Co、Zn等共存元素干扰严重.用100mg/L的Fe作为基体改进剂可消除上述共存元素的干扰,测定结果令人满意.     

改性竹炭对水溶液中Cu(Ⅱ)、Cd(Ⅱ)的吸附性能

采用不同方法对竹炭进行改性,寻求吸附效果最好的改性产品,并研究其对溶液中Cu2+、Cd2+的吸附性能,考察了吸附时间、溶液pH值、吸附温度和溶液初始浓度对吸附效果的影响,同时与未改性竹炭的吸附性能进行了对比。实验结果表明:相同条件下,氧化改性竹炭对Cu2+、Cd2+的吸附效果明显优于其他方法改性竹炭和未经改性的竹炭。吸附温度为15℃、25℃、45℃时,氧化竹炭对Cu2+的最大吸附量分别为6.653mg/g、6.702mg/g和7.897mg/g,而氧化竹炭对Cd2+的最大吸附量分别为1.700mg/g、1.826mg/g和2.282mg/g。氧化改性竹炭对Cu2+、Cd2+的吸附均符合Freundlich方程和Langmuir方程。实验证明,氧化竹炭是一种应用前景广泛的重金属离子吸附剂。     

Comparative analysis on homogeneity of Pb and Cd in epoxy molding compounds

Reference materials for quantitative determination of regulated heavy metals, such as Pb and Cd in electronic components, were designed and investigated in terms of stability and homogeneity. Reference materials with two concentration levels of heavy metals were prepared by spiking Pb and Cd compounds to epoxy molding compounds made by mixing silica powders and epoxy resin. The concentration changes of the reference materials during stability test for 1 a were not observed. In the homogeneity assessment, the as-prepared reference materials were studied by using three different analytical tools, inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray fluoroescence spectrometry (XRF) and laser ablation ICP mass. The results show different homogeneities by the characteristics of analytical tools and the materials.