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941.
研究了聚环氧乙烷(PEO)/聚2-乙烯基吡啶(P2VP)的共混物分别经LiCLO4、四氰基代苯醌二甲烷(TCNQ)及两者共同掺杂后其共混物的离子、电子及混合导电率。当PEO与P2VP的重量比分别为6/4、5/5及4/6时,共混物的混合导电率大于相应的离子及电子导电率的总和,呈现协同效应。从共混物外观的研究发现LiCLO4能作为PEO/P2VP共混体系的增容剂。 相似文献
942.
采用分子量500万的聚氧化乙烯和无水溴化铜,通过混溶蒸发法制备成高聚物固体电解质P(EO)n-CuBr2薄膜,并在0.1~300MPa范围不同的流体静水压下详细测量其复平面阻抗谱,分别得到在不同压力下离子电导率和介电常数与测量频率的关系.进一步解谱准确地求出P(EO)n-CuBr2(n=12、16)薄膜离子电导率和介电常数的静水压效应,并结合X-光物相分析,根据离子迁移通道的物理图象和高聚物的极化机构进行了初步的讨论.添加20%的增塑剂碳酸丙烯酯,较大改进了压力下的导电性.120~300MPa的离子电导率提高一个数量级 相似文献
943.
E. I. Zhilyaeva S. A. Torunova R. N. Lyubovskaya R. B. Lyubovskii 《Russian Chemical Bulletin》1996,45(5):1107-1110
Radical cation salts with halide mercurate anions were obtained by the electrochemical oxidation of bis(ethylenedioxo)tetrathiafulvalene (BEDO-TTF), and their conductivity was studied. The compounds (BEDO-TTF)4Hg3X8 (X = Cl or Br), (BEDO-TTF)4Hg3.5I9, and (BEDO-TTF)2HgBr3 possess the conductivity of the metallic type down to helium temperatures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1167–1170, May, 1996. 相似文献
944.
P. Pissis A. A. Konsta S. Ratkovič S. Todorovič J. Laudat 《Journal of Thermal Analysis and Calorimetry》1996,47(5):1463-1483
Broad-band ac dielectric relaxation spectroscopy (DRS) and various techniques of thermally stimulated currents (TSC) have been used to investigate molecular mobility in cereal and legume seeds, over wide ranges of water content and temperature. We focused our interest on the detailed study of the interactions between water and seed constituents. The results are quantitatively discussed, using various concepts dictated by the experimental techniques employed and in relation to the protein and carbohydrate contents of the seeds. In addition, the glass transition in the seeds, freezing and melting of water, and the protonic conduction process have been studied in some detail.Financial support through the Greek Ministry of Industry, Energy and Technology (Secretariat of Research and Technology), the Czech Ministry of Education, Youth and Sport (Dept. of International Scientific and Technological Cooperation), and the Empirikos Foundation is gratefully acknowledged. 相似文献
945.
The effects of lithium oxide dopants (0.5–0.8 at. % Li) on the electrophysical and sorption properties of ZnO were studied in the temperature range from 150 °C to 410 °C. The introduction of lithium increases the activation energy of the conductivity of ZnO, decreases its conductivity, and increases the amount of S02 sorbed. Two forms of chemisorbed SO2 (donor and acceptor) are observed on the surface.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1096–1100, May, 1996. 相似文献
946.
酞侧基聚芳醚酮的热学性能谢红卫,李滨耀(中国科学院长春应用化学研究所长春130022)关键词酞侧基聚芳醚酮,pvT行为,导热系数,定压比热容酞侧基聚芳醚酮(PEK-C)具有较高的玻璃化转变温度,其流变加工性能和力学性能已被广泛研究[1~3],被证明是... 相似文献
947.
948.
本文研究了内核经硫加金增感的内敏核壳乳剂的感光性能和离子性能。内核化学增感时Na2S2O3和AuCl3两者的加入量按一定比例增大时,内部感光度升高,表面感光度下降,离子电导率略有降低。内核化学增感时如果单独增加AuCl3的用量,内部感光度有所升高,表面感光性能基本不变,离子电导率略有下降。内核化学增感结束引入稳定剂583,可使内显灰雾明显降低,离子电导率也有所下降,核壳比增大造成内部感光度上升而表面感光度下降,离子电导率也有所下降。表面引入碘后,离子电导率明显上升。 相似文献
949.
This paper reports the results of a variety of experiments carried out for understanding the solvation behavior of potassium thiocyanate in methanol–water mixtures. Electrical conductivity, speed of sound, viscosity, and FT-Raman spectra of potassium thiocyanate solutions in 5 and 10% methanol–water (w/w) mixtures were measured as functions of concentration and temperature. The conductivity and structural relaxation time suggest the ion–solvent and solvent-separated ion–ion associations increase as the salt concentration increases in the mixtures. The Raman band shifts due to the C–O stretching mode of methanol for the solvent mixtures reveal the formation of methanol–water complexes. The significant changes in the Raman bands for the C–N, C–S and O–H stretching modes indicate the presence of SCN−−solvent interactions through the N-end, “free” SCN− and the solvent-shared ion pairs as potassium thiocyanate is added to the methanol–water mixtures. The relative changes corresponding to H–O–H bending and C–O stretching frequencies indicate that K+ is preferentially solvated by water in these solvent mixtures. The appearance and increase of the intensity of a broad band at ≈940 cm−1 upon salt addition was attributed to the SCN−–H2O–K+ solvent-shared ion pairs. No Raman spectral evidence for K+(H2O)n species was observed. The preferential solvation of K+ and SCN− in the methanol−water mixtures was verified by the application of the Kirkwood−Buff theory of solutions. This theory confirms that K+ is strongly preferentially solvated by water, whereas SCN− is preferentially solvated by the methanol component. 相似文献
950.
The separation and detection of commonly used preservatives (benzoate, sorbate) and vitamin C by both conventional CE and microchip electrophoresis with capacitively coupled contactless conductivity detection is presented. The separation was optimized by adjusting the pH-value of the buffer and the use of hydroxypropyl-beta-CD (HP-beta-CD) and CTAB as additives. For conventional CE, optimal separation conditions were achieved in a histidine/tartrate buffer at pH 6.5, containing 0.025% HP-beta-CD and 0.1 mM CTAB. LOD ranged from 0.5 to 3 mg/L (S/N = 3) and the RSDs for migration time and peak area were less than 0.1 and 2%, respectively. A considerable reduction of analysis time can be accomplished by using microchip electrophoresis without significant loss in sensitivity under optimal separation conditions. A histidine/tartrate buffer at pH 6.5, incorporating 0.06% HP-beta-CD and 0.25 mM CTAB, gave detection limits ranging between 3 and 10 mg/L and satisfactory reproducibilities of < or =0.4% for the migration time and < or =3.5% for the peak area. The methods developed are useful for the quantitative determination of food additives in real samples such as soft drinks and vitamin C tablets. 相似文献