麦秆添加大量CaO热解的TG-FTIR实验研究

利用热重-傅里叶变换红外光谱联用方法研究添加CaO对麦秆热解过程和挥发份析出特性的影响.热重和红外光谱分析均表明添加CaO后麦秆热解旱现两个明显的失重和挥发份析出阶段,而纯麦秆热解则只有一个.CaO在第一阶段不但能够吸收CO2,而且能够降低甲苯、苯酚和蚁酸等焦油类物质的产生,使得该阶段失重率和最大失重速率随CaO添加量增加而减小.CaCO3的煅烧分解是添加CaO麦秆热解第二阶段产生的原因,该阶段失重率和最大失重速率随CaO添加量增加而增大.研究结果表明,在采用生物质为原料的零排放系统中添加CaO有利于捕获CO2和减少焦油物质的产生,系统的气化温度应适当降低以防止CaCO3的煅烧分解.     

Lithium extraction/insertion process on cubic Li-Mn-O precursors with different Li/Mn ratio and morphology

The cubic phase LiMn₂O₄ precursors are prepared by high-temperature calcinations (1003 K) of LiOH⋅H₂O and MnO₂ mixture with Li/Mn molar ratio = 0.55. The Li₄Mn₅O₁₂ precursors are synthesized via low-temperature solid-phase reaction (673 K) of LiNO₃ and MnO₂ mixture with Li/Mn molar ratio = 1.0. The ion-sieves counterparts (named SMO-H and SMO-L, respectively) are obtained by the acid treatment of Li-Mn-O precursors. The structure, chemical stability, morphology, ion-exchange property and mechanism of Li-Mn-O precursors and MnO₂ ion-sieve were systematically examined via X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), Infrared Spectroscopy (IR), X-ray photoelectron spectroscopy (XPS) and lithium ion selective adsorption measurements. The result shows the more compact Mn-O lattice makes the Li₄Mn₅O₁₂ spinel more stable after the Li⁺ is extracted. The results of IR and XPS show adsorption process of SMO-H exists ion-exchange between the Li⁺ and protons, and redox reaction, but only exists ion-exchange between the Li⁺ and protons in SMO-L. Agglomeration is well-improved by low calcination temperature and the morphology of the Li₄Mn₅O₁₂ precursor and final MnO₂ ion-sieve are effectively controlled within low-dimensional structure. The maximum pH titration capacity of SMO-L for Li⁺ is 6.76 mmol⋅g⁻¹, but only 3.47 mmol⋅g⁻¹ for SMO-H. The ion-sieve obtained from Li₄Mn₅O₁₂ precursor is promising in the lithium extraction from brine or seawater.     

Construction of a magnetic chiral coordination polymer based on a semi-rigid carboxylic acid

A 2-D chiral entangled coordination polymer, {Mn₃(2,2′-bpy)₂(3-cpta)₂·H₂O}_n (1) (3-H₃cpta=3-(3′-carboxyphenoxy)phthalic acid, 2,2′-bpy=2,2′-bipyridine), has been synthesized via the solvothermal method. X-ray diffraction analysis reveals that 1 consists of one right-handed helical chain and one wavelike 2-D plane, which are connected with each other through hydrogen bonds and π···π interactions to generate a 3-D supra-molecule. Thermal gravimetric analysis shows that 1 possesses good thermal stability. Temperature dependent magnetic susceptibilities have also been measured from 1.8 to 300 K, which shows 1 to be anti-ferromagnetic.     

基于原子转移自由基聚合制备新型螯合树脂及其吸附性能

以氯甲基化聚苯乙烯树脂(CMPS)为基质, 通过表面引发原子转移自由基聚合(SI-ATRP)反应将聚甲基丙烯酸缩水甘油酯(PGMA)接枝到树脂表面, 再与亚氨基二乙酸(IDA)反应, 制备了一种新型螯合树脂. 采用红外光谱、 元素分析及比表面积与微孔分析仪对其结构进行表征. 树脂表面甲基丙烯酸缩水甘油酯(GMA)接枝量和IDA含量及对Ni(Ⅱ), Cu(Ⅱ)和Pb(Ⅱ)的吸附容量均随聚合时间的延长而增大, 聚合时间为18 h时, 最大吸附容量分别为1.29, 1.19和0.83 mmol/g. 结果表明, SI-ATRP是制备高吸附容量及吸附容量可控的螯合树脂的可行方法.     

LiMn_2O_4离子筛成型及锂吸附性能

采用PVC为粘结剂制备了LiMn_2O_4离子筛球型颗粒,分析了PVC添加量对离子筛吸附性能的影响,并通过扫描电境(SEM)、静态和动态连续锂吸附实验研究了PVC粘结剂对离子筛形貌和锂离子吸附性能的影响。结果表明,SMO-a、SMO-b和SMO-P样品的锂离子静态吸附数据与Lagergren方程吻合良好,吸附速率常数依次为1.03×10~(-5)、1.06×10~(-5)s~(-1)和9.72×10~(-6)s~(-1)SMO-a样品的静态饱和吸附量达到2.50 mmol·g~(-1),PVC造粒对离子筛的静态条件下的饱和吸附容量和吸附速率影响很小,但连续动态操作条件下SMO-a的吸附容量降低为1.11 mmol·g~(-1);经盐酸洗涤脱附后,Li~+最大富集倍数约为9。     

Synthesis of a new macrocyclic compound and its self-assembly

A new macrocyclic compound has been synthesized by condensation of pyridine-1-oxide-2,6-dialdehyde with diethylenetria-mine. The self-assemly behaviours were studied by X-ray diffraction. The results show that the self-assembly were controlled by intermolecular hydrogen bonds and π-π stacking effects.     

Raman光谱研究铜锌超氧化物歧化酶及其金属取代衍生物的二级结构

本文测定了铜锌超氧化物歧化酶（Cu2Zn2SOD)及其金属取代衍生物Cu2Ni2SOD的Raman光谱,对图谱进行了归属,并定量测定了两种SOD的二级结构,同时对结构与活性的关系进行了讨论。     

在Ni~（2＋）存在下二氧四胺大环配体液膜传输Cu~（2＋）的动力学研究

研究了１２－十八烷基－１，４，７，１０－四氮杂环十三烷－１１，１３－二酮的氯仿－正辛醇液膜在Ｎｉ~（２＋）存在下对Ｃｕ~（２＋）的传输速率，结果表明，传输是通过中性配合物进行的，无阴离子参与。Ｎｉ~（２＋）的存在对Ｃｕ~（２＋）的传输基本无影响。     

A study on hydrolytic polymerization of lanthanide ions

Experimental data of hydrolytic polymerization of lanthanide ions in aqueous solution were treated by graphic method, computer fitting and pq analysis, species present were ascertained and hydrolysis constants obtained. Ln (OH)²⁺ and Ln₂ (OH)₂⁴⁺ predominated in the species of all hydrolysis products. When the first and the second hydrolysis constants were plotted against radii and effective nuclear charge of lanthanide ions, the curves obtained conformed with the “three-division groups” rule. Correlation between hydrolysis constants of Ln₂ (OH)₂⁴⁺ and other hydrolysis constants is linear. Using the above empirical correlations we calculated hydrolysis constants of all lanthanide ions and obtained satisfactory results which showed good regularity for hydrolysis of lanthanide ions and thus systematized all data of the reaction.     

A study on Cu2Co2SOD and Co2Co2SOD by voltammetry and thin-layer spectroelectrochemistry

The electrochemistry of Co(2)Co(2)SOD and Cu(2)Co(2)SOD on a pyrolytic graphite electrode (PGE) without using mediators was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The reversible and quasi-reversible voltammetric responses were observed for Co(2)Co(2)SOD and Cu(2)Co(2)SOD, respectively. Their formal redox potentials and electron numbers involved in electrode reactions were obtained, and are in agreement with those by spectroelectrochemistry (SEC).