乙丙三元共聚物磺酸锰离聚体溶液中离子的相互作用

乙丙三元共聚物(EPDM)磺酸盐离聚体在二甲苯/正己醇中具有特异的粘度-浓度及粘度-温度关系,前文用波谱方法考察了离聚体溶液中的离子相互作用。本文以含Mn~(2+)(核自旋数5/2)的EPDM磺酸盐(SEPDM-Mn)为对象,且与Mg盐(SEPDM-Mg)离聚体比较,讨论了比浓粘度与溶液浓度及温度的关系,用FTIR和ESR方法对离聚体溶液作进一步考察,发现     

LiCl、MgCl_2和CaCl_2乙醇溶液体系的溶剂化研究

利用红外光谱技术及量子化学方法研究了LiCl、MgCl2和CaCl2在乙醇溶液中的离子溶剂化作用现象。乙醇溶液C—O振动峰的变化及O—H伸缩振动峰发生的蓝移表明,金属离子与乙醇分子发生了相互作用。通过量子化学方法对金属离子的配合物结构进行了优化和热力学计算,并利用波恩方程理论计算出单个离子的溶剂化自由能,对比量子化学方法计算得出的吉布斯自由能,可以得到溶液中离子存在的稳定构型,验证溶液中发生了溶剂化现象。     

离聚体的结构表征——Ⅴ.含氟离聚体中离子微区稳定性的研究

本文用DSC方法研究了羟酸型含氟离聚体中不同金属离子种类、可离子化基团含量、配位结构单元构型及离子微区大小对离聚体中离子微区稳定性的影响。实验表明:离聚体中金属离子配位能力愈强,羟酸含量愈高,离子微区尺寸愈大,则相应离聚体中离子微区稳定性愈大。铅高聚体>锌离聚体>钙离聚体>钠离聚体。     

含氟离聚体的多相结构及大分子链运动的NMR研究

本文用~(13)C自旋-自旋弛豫时间T_2表征了以丙烯酸-1,1,5-三氢全氟戊酯-丙烯酸共聚物为基础的离聚体体系的多相结构和大分子链段运动特性,结果表明:离子微区和聚合物基体之间存在界面层,聚合物主链的运动活性与离聚体的共聚物组成、金属离子特性、离子化程度、离子微区的稳定性和离子微区内的精细结构均有密切关系.     

离聚体溶液

离聚体（ionomer）是指含离子基团低于15mol％的聚合物，这些离子基团能聚集成多重离子对[1]或离子簇[2-6]，使大分子链发生物理文联形成聚集体，导致性质起很大变化。例如常温下因物理交联而具有良好弹性，而高温时物理交联被破坏而具有流动性，所以离聚体能制成热塑性弹性体。由于物理交联存在，离聚体不能轻易溶于非极性溶剂中；由于离子含量低，又不易溶于水或其它强极性溶剂中．因此，尽管离聚体固体的研究和应用已有40多年的历史，但有关溶液研究的报导到70年代末才见发表[7-9]，近10年取得较大进展，其独特的粘度关系使人们考虑利用…     

磺化丁基橡胶离聚体在溶液中的聚集行为(Ⅰ)──ESR谱研究

用ESR谱考察了磺化丁基橡胶锰盐(Mn-SIIR)离聚体在二甲苯/醇(少量)混合溶剂中的离子聚集行为。结果表明,在所考察的范围内,浓度及磺化度增大时ESR谱的形状变化不大,这反映了离子聚集程度并没有发生明显变化;另外,极性共溶剂(醇)增多时,谱线分辨度增大,反映了离子聚集程度下降;温度升高时谱线变模糊,反映离子聚集程度增大。这些结果有力地支持了Lundberg等人提出的离聚体溶液粘度变化平衡式。     

磺化丁基橡胶离聚体在混合溶剂中的聚集行为

用顺磁共振（ESR）谱和粘度法考察了磺化丁基橡胶离聚体在二甲苯／正己醇混合溶剂中的聚集行为．ESR谱表明离聚体的离子基团发生聚集，其聚集程度受极性共溶剂（正己醇）的影响．粘度考察表明，在不同的浓度时离子基团有不同的聚集形式，低浓度时以分子内聚集为主，高浓度时以分子间聚集为主．离聚体的聚集度（DA）与浓度（c）的关系可用经验式DA＝Aexp（kc2）表示，其中A、k为常数．k值反映聚集度受浓度影响的程度，醇含量增大时k值减小，这是因为醇对离子的溶剂化作用导致离子聚集的倾向减小．     

聚苯醚羧酸盐的链结构

本文用热学,力学和光散射方法研究了聚苯醚羧酸盐的链结构。羧化聚苯醚(CPPO)在二氧六环溶液中用0.5N NaOH(或 CsOH)的醇水溶液中和成钠型或铯型的 CPPO 离聚体,用 DSC测定一系列羧盐含量的 CPPO 离聚体的玻璃化转变温度得到形成离子微区的临界阳离子浓度约为5mol%,动态力学谱中在高于玻璃化转变温度域出现的α松弛峰亦证明了微相结构的存在。SAXS 结果表明其离子微区的尺寸约为3nm,其尺寸大小和离聚体中阳离子浓度无关。     

离聚体溶液粘度方程

离聚体（ionomer）是指合少量离子基团（低于15％mo）的聚合物．在低极性溶剂中，离子基团发生聚集，因而离聚体溶液的粘性行为明显不同于普通高分子溶液．很多实验表明［1］，用于描述普通高分子溶液粘性行为的哈金斯公式并不适用于描述离聚体溶液的粘性行为．因此，到目前为止，对离聚体溶液的离子聚集行为及粘性行为的考察或者是定性的，或者是通过图表曲线直接描述的．本文提出适用于高聚体溶液的半经验关系式，并用实验数据验证，以求更深入和更系统地研究离聚体溶液的粘性行为．1实验部分采用两种分子量的丁基胶（牌号286，加拿大产品…     

离聚物共混体系在溶液中分子间缔合的粘度研究

研究了磺化聚苯乙烯离聚体／聚（苯乙烯 ４ 乙烯吡啶）共混体系、磺化聚苯醚离聚体／聚（苯乙烯 ４ 乙烯吡啶）共混体系和磺化聚苯醚离聚体／胺化聚苯醚共混体系在氯仿／甲醇混合溶剂中的粘度行为，结果表明，和它们分别对应的不含离子基的共混物相比，这三个共混体系都表现出较高的比浓粘度．这是由于体系中的酸基及其盐和含氮碱基的引入，在共混组分间产生了强烈的离子相互作用，从而导致分子间的缔合，使比浓粘度提高．并讨论了溶剂体系、功能基种类及共混组分的主链结构等因素对这种分子间缔合作用的影响．     

含不同金属离子的EPDM磺酸盐离聚物的研究

合成了含不同金属离子Na~+、Mg~(2+)、Zn~(2+)和Al~(3+)的四种乙丙三元共聚物(EPDM)磺酸盐离聚物, 红外光谱和氧瓶燃烧法测定了磺酸基的存在和含量。动态力学结果表明, 离聚物中碳酸盐基团可能以多重离子对形式聚集; 热重法指出, EPDM磺酸盐的热稳定性为钠盐>锌盐>镁盐>铝盐。考察了它们在二甲苯-正己醇混合溶剂中, 比浓粘度随浓度、温度变化的规律, 初步分析了各种金属盐的差异及其原因。     

Paramagnetic probes for the investigation of ordered and disordered perfluorosurfactants,perfluoropolyethers and perfluorinated ionomers

In this review we describe the use of transition metal ions (Cu²⁺, Ti³⁺, VO²⁺, Mn²⁺) and stable nitroxide radicals with different shape, size and charge as paramagnetic probes for the study of perfluorinated compounds in the presence of solvents by electron spin resonance (ESR, ESE, ENDOR) spectroscopy. The physical state of the swelling solvents in perfluorinated ionomers (Nafion and perfluoropolyethers) is deduced by the analysis of the ESR spectral parameters and linewidths as a function of the operating frequency and temperature. The formation of metal aggregates in aqueous and nonaqueous solvents is discussed. The spectral characteristics and relaxation behavior of nitroxides is particularly informative when aggregates such as micelles, lamellar phases and other ordered systems, are formed in solution.     

红外光谱法研究磺化间规聚苯乙烯离聚物离子间相互作用

采用红外光谱法研究了不同金属阳离子及水合作用对磺化间规聚苯乙烯 (SsPS)离聚物阴、阳离子间相互作用的影响 .实验结果表明 :离间相互作用的强弱可通过红外光谱表现出来 ,SsPS离聚物中磺酸根阴离子 (SO-3 )的红外吸收谱带与金属阳离子的性质及离聚物所处的环境有关 .在干燥状态下 ,SsPS离聚物中磺酸根阴离子 (SO-3 )由于受到金属阳离子静电场作用的影响 ,S—O键被极化而使其对称伸缩振动和不对称伸缩振动吸收峰移向高波数 ,移动的幅度与金属阳离子的性质有关 .离聚物吸水后 ,由于水合作用的影响 ,金属阳离子的极化作用减弱 ,因而使S—O键相应的对称伸缩振动和不对称伸缩振动吸收谱带移向低波数 .对于未中和的磺化间规聚苯乙烯 (SsPS H)样品 ,水合作用会使磺酸基团部分离解 ,产生磺酸根阴离子 (SO-3 ) .在干燥状态下 ,磺酸基团仍以—SO3H形式存在 ,红外谱图上出现—SO3H基团的特征吸收     

Coordination numbers of hydrated divalent transition metal ions investigated with IRPD spectroscopy

Hydration of the divalent transition metal ions, Mn, Fe, Co, Ni, Cu, and Zn, with 5-8 water molecules attached was investigated using infrared photodissociation spectroscopy and photodissociation kinetics. At 215 K, spectral intensities in both the bonded-OH and free-OH stretch regions indicate that the average coordination number (CN) of Mn(2+), Fe(2+), Co(2+), and Ni(2+) is ~6, and these CN values are greater than those of Cu(2+) and Zn(2+). Ni has the highest CN, with no evidence for any population of structures with a water molecule in a second solvation shell for the hexa-hydrate at temperatures up to 331 K. Mn(2+), Fe(2+), and Co(2+) have similar CN at low temperature, but spectra of Mn(2+)(H(2)O)(6) indicate a second population of structures with a water molecule in a second solvent shell, i.e., a CN < 6, that increases in abundance at higher temperature (305 K). The propensity for these ions to undergo charge separation reactions at small cluster size roughly correlates with the ordering of the hydrolysis constants of these ions in aqueous solution and is consistent with the ordering of average CN values established from the infrared spectra of these ions.     

3d金属离子对H2O2氧化活性艳红的催化性能

以H2O2氧化活性艳红为研究对象,探讨了七种3d金属离子的催化性能、影响因子及其作用、氧化降解动力学和催化作用机理．通过对pH值、氧化剂用量、金属离子浓度、温度的影响研究,确定了七种3d轨道过渡金属离子的催化性能大小为：Fe^3＋〉Cu^2＋〉Co^2＋〉Mn^2＋〉Cr^3＋〉Ni^2＋〉Zn^2＋．在此基础上得到了该催化氧化反应的一级动力学模型,通过一级动力学模型求得各个金属离子的表观活化能,从活化能的大小得出受温度影响大小的顺序为：Cr^3＋〉Mn^2＋〉Co^2＋〉Cu^2＋〉Ni^2＋〉Zn^2＋〉Fe^3＋．     

Antimony-121 Mössbauer spectral study of the Eu14MnSb11 and Yb14MnSb11 Zintl compounds

The antimony-121 M?ssbauer spectra of the Yb14MnSb11 and Eu14MnSb11 Zintl compounds have been measured between 2 or 5 and 300 K. The resulting three-dimensional arrays of the spectral counts, velocity, and temperature have been simultaneously fit with a minimum number of free parameters. These fits yield a 0 Kelvin transferred hyperfine field of 2.9(2) T, a Curie temperature of 57(3) K, and a M?ssbauer temperature of 182(2) K for Yb14MnSb11; in this case the transferred field arises solely from the ordering of Mn2+. Because Eu14MnSb11 has both Eu2+ and Mn2+ ions that are magnetically ordered, its antimony-121 M?ssbauer spectra are more complex and reveal two magnetic transitions, the first at 92(1) K resulting from the ordering of the Mn2+ ions and the second at 9.5(1.0) K resulting from the ordering of the Eu2+ ions; the corresponding 0 Kelvin transferred hyperfine fields are 1.3(1) and 3.7(1) T. The antimony-121 isomer shifts yield electronic configurations of 5s1.745p4.28 and 5s1.745p4.19 for the average antimony anion in Yb14MnSb11 and Eu14MnSb11, respectively.     

THE THEORETICAL STUDY OF ADSORPTION OF METAL IONS ON CHITOSAN

The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency analysis of all cluster models have been performed employing B3LYP hybrid method at 3-21G basis set level except metal ions which were invoked to use effective core potential (ECP) method. The energy changes, and the main structural parameters have been obtained during the theoretical study of the adsorption of metal ions on the chitosan. The calculations showed that the coordination modes of metal ions with chitosan models were different, the geometries of Mn2+, Zn2+, Cd2+, Hg2+, Pb2+ ions coordinated with two nitrogen atoms and two oxygen atoms were distorted tetrahedral, while the square planar structure of Ni2+ coordinated two nitrogen atoms and two oxygen atoms was observed. The heat of reaction between six metal ions and chitosan models showed the order: Mn2+ ＞Ni2+ ＞Zn2+ ＞Pb2+ ＞Hg2+ ＞Cd2+, this suggested that the coordination strength of Mn2+ ＞Ni2+ ＞Zn2+ ＞Pb2+ ＞Hg2+ ＞Cd2+.     

Solution properties of ionomers. I. Counterion effect

The effect of counterions on the solution properties of two types of ionomers, one based on sulfonated polystyrene and the other based on styrene–methacrylic acid copolymer, was studied by viscosity and light scattering measurements. It was found that the order of counterion binding of ionomers in a polar solvent and the order of aggregation of ionomers in a low-polarity solvent were the same for the same ionomer system. However, the order for the sulfonated ionomer was Li < Na < K < Cs, whereas that for the carboxylated ionomer was the opposite. This can be explained by a difference in desolvation during anion–cation interaction and by considering site-binding in a polar solvent and the association of ion pairs in a low-polarity solvent. These findings for ionomer systems are parallel to the association behavior of small ions in water, cation affinity in crosslinked resins, and counterion binding of polyelectrolytes in water.