水杨酸在超临界二氧化碳中络合萃取汞离子

测试水杨酸在超临界二氧化碳中的溶解度数据,研究了水杨酸络合剂在超临界二氧化碳中萃取汞离子,分别讨论了配比、压力、温度、时间对萃取效率的影响。得到了最佳的萃取条件为20 MPa、323 K、45 min和[Hg+]:[SAL]:[PFOSANEt4]=1:200:200,在最佳萃取条件下萃取效率达到95.5%,可以进行工业领域的推广应用。水杨酸作为络合剂在超临界二氧化碳中萃取汞离子的研究未见有关报道。     

纳米石墨包覆球形LiFePO_4正极材料的制备及其性能研究

采用湿球研磨-喷雾干燥法合成了纳米石墨包覆的球形LiFePO_4材料。该材料呈现了大小较为均匀的球形颗粒,颗粒度较小。性能测试表明该材料具有优异的电化学性能,最佳样品C在0.1 C时的放电比容量为160.9 m A·h·g~(-1),在高倍率5 C下的比容量仍为120.5 m A·h·g~(-1),显示了良好的比容量维持率。该法制备细小而致密的球形颗粒,并通过纳米石墨包覆增强导电性,大大提高了LiFePO_4材料的电化学性能,此方法简便、高效,有工业化应用的前景。     

Complex Formation of Divalent Cations with Carboxylic Acid Resins as a Factor Determining Different Stationary States of Their Swelling

Three samples of carboxylic acid gel-type cross-linked polyelectrolytes were examined by registering the extent and kinetics of their volume change depending on the temperature, concentration, and nature of external electrolyte solutions, as well as the initial state (ionic form, water content) of the bead. It is found that in some systems the swelling of the bead (as a result of lowering the temperature) proceeds much more slowly than the preceding shrinking (as a result of the increase of temperature). Moreover, the initial volume of the bead is not restored, and a new stationary state of swelling is established. By means of optical dilatometry, it is found that in the systems in which the differences in the stationary states of swelling are found, the beads display plasto-elastic properties, whereas in the absence of such differences the beads show elastic properties. It is found that different stationary states of swelling are also established when the beads of copolymer of methacrylic acid cross-linked with divinylbenzene in Na⁺ form in the dry state and in the NaCl solution-swollen state are placed into a solution of a divalent cation salt. The difference in the stationary states of swelling reaches 12% in 4 N NiCl₂ solution. The substantial differences in the swelling behavior and viscoelastic properties of the resins in their Na⁺, Mg²⁺, Ca²⁺, and Ni²⁺ forms are interpreted in terms of formation of different kinds of complexes of functional groups of the polymer with Ca²⁺ and Ni²⁺ ions.     

Ionic Liquid (IL) Cation and Anion Structural Effects on Metal Ion Extraction into Quaternary Ammonium-based ILs

Numerous factors have previously been shown to influence the mode of extraction of alkali and alkaline earth cations from an acidic aqueous phase into 1, 3-dialkylimidazolium-based ionic liquids (ILs) by a crown ether, among them the hydrophobicity of both the IL anion and cation. To determine if this observation is “generic” and thus, could provide the basis for guidelines for the rational design of ILs to be used as solvents in metal ion extraction, other families of ILs must be studied. A series of quaternary ammonium-based ILs have therefore been examined as solvents for the extraction of various metal ions from acidic nitrate- and chloride-containing aqueous phases by dicyclohexano-18-crown-6 (DCH18C6). Although the overall metal ion extraction behavior in these systems is similar to that observed for 1, 3-dialkylimidazolium-based ILs, significant differences in metal ion separation factors (e.g., α_Sr/Na) are observed under certain conditions, differences that may be sufficient to influence the choice of IL in separations applications.     

聚吡咯/活性炭复合电极对不同离子电吸附性研究

将小阴离子掺杂聚吡咯/活性炭(PPy/AC)复合电极与常规炭电极组装成非对称离子交换膜电容脱盐(MCDI)单元,研究了其对不同荷电量、水合半径离子的吸附性能差异。结果显示:当复合电极分别作为脱盐单元的正极或负极时,其电容吸附过程的离子尺寸依赖效应差异显著,这应该与复合电极氧化还原过程的孔径尺寸变化有关。     

毛细管气相色谱法同时测定三氯乙烯及其脱氯产物

建立了一种同时测定水中三氯乙烯及其脱氯产物的气相色谱检测方法。采用顶空进样,毛细管柱分离,氢火焰离子化检测器检测,保留时间定性,峰面积定量。以三因子三水平正交试验法确定了最佳检测条件,各组分线性良好(R20.998),相对标准偏差3.79%~9.14%,平均加标回收率97.68%~119.18%。对氯代烯烃而言,灵敏度虽较电子捕获检测器低,但新方法操作简便、快速、干扰少、准确度也较高,能满足三氯乙烯污染修复中反应物及中间产物的检测要求。     

Pb~(2+)在粉煤灰基方钠石上的吸附特性

以电厂粉煤灰为原料,在传统碱熔-水热法中引入脱硅工艺制备粉煤灰基方钠石,运用XRD和SEM对其进行物相和形貌表征,并通过研究不同因素条件下Pb~(2+)的吸附行为来考察Pb~(2+)在粉煤灰基方钠石上的吸附特性。结果表明:在碱度4.5 mol/L、晶化时间12 h、晶化温度100℃条件下能够合成出较高纯度的粉煤灰基方钠石;合成的方钠石相比原状粉煤灰吸附能力显著提高,对Pb~(2+)具有显著的去除效果,可作为重金属处置的高效吸附剂。     

影响胶料中游离硫含量变化关键因素的研究

本文主要介绍利用高效液相色谱法对胶料中游离的可溶性硫含量的测试方法。并模拟混炼与压延生产工艺生产条件,考察影响胶料中游离的可溶性硫含量的关键因素,为实际生产工艺条件的选择与调变提供技术支撑。     

Analysis of Polycyclic Aromatic Hydrocarbon,Toxic Equivalency Factor and Related Carcinogenic Potencies in Roadside Soil within a Developing City of Northern India

Preliminary analysis was performed to assess contamination levels in roadside soils, distribution behavior and human exposure with Polycyclic Aromatic Hydrocarbons (PAHs) during summer, winter, rainy, and autumn during 2013 in one of the developing cities of northern India. The concentration of PAHs was measured at ten different locations (at 1, 2, and 3 m) from roadside soil. Recovery range was 30% and 80% with lower value corresponding to the lower molecular weight PAHs compound. Identification and quantification of PAHs was done by GC-FID. Average PAHs concentration (city average) was found to be 16.53, 4.04, 17.49, and 7.82 μg g^?1, during summer, winter, autumn, and the rainy seasons, respectively. Average concentration of low and high carcinogenic PAHs during summer, winter, autumn, and rainy was 5.1 and 31.29, 2.1 and 6.4, 4.74 and 35.08, 3.97 and 12.77μg g^?1_, respectively. The average ratio of low and high carcinogenic PAHs was found to be 1:6, 1:3, 1:7.6, and 1:3.21 during summer, winter, autumn, and the rainy seasons at most intercepts. Dib(ah)A and B(a)P were the two individual PAHs found in highest concentration during summer, winter, and the rainy seasons, whereas B(a)P and IP were individual PAHs found in highest concentration during autumn. It was also analyzed that high carcinogenic PAHs concentration was quite higher (around 85%) in comparison to low carcinogenic PAHs (around 15%) at most intercepts. This article also deals with the behavior of PAHs at places of average/high population and traffic density intercepts. Five-ringed PAHs were in highest concentration at all intercepts and seasons. Two-tailed T test was applied for authenticity of the data and results. Toxic equivalency factor of B(a)P and Dib(ah)A was maximum as compared to other PAHs.