Morphology of conductive blend fibers of polyaniline and polyamide-11

Polyaniline (PANI), a member of the intrinsically conducting polymer (ICPs) family, was blended with polyamide-11 (polyco-aminoundecanoyle) in concentrated sulfuric acid. The above solution was used to spin conductive PANI/polyamide-11 fibers by wet-spinning technology. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed to study the two-phase morphology of the conductive PANI/polyamide-11 fibers. The micrographs of the cross-section, the axial section and the surface of the monofilament demonstrated that the two blend components were incompatible. The morphology of PANI in the fibers was of fibrillar form, which was valuable for producing conducting channels. The electrical conductivity of the fibers was from 10(-6) to 10(-1) S/cm with the different PANI fraction and the percolation threshold was about 5 wt.%. By comparing the two blend systems of PANI/Polyamide-11 fibers and carbon black filled poly(ethylene terephthalate) (PET) fibers, it was shown that the morphology of the conductive component had an influence on electrical conductivity, The former had higher conductivity and lower percolation threshold than the latter. (C) 2001 Elsevier Science B.V. All rights reserved.

New microsystem of capillary electrophoresis with amperometric detection

We have made a cheap microsystem of capillary electrophoresis with a new method, integrating the electrodes, injection channel, separation channel, buffer reservoirs and detection cell on a polymethylmethacrylate (PMMA) chip. Using an integrated micro carbon fiber disk electrode as the working electrode in three electrodes system, 1 x 10(-4) mol/L dopamine(DA) could be detected with end-column amperometric detection. The reproducibility was good. Peak current was 6.73 nA,theoretical plate number was 71300/m and height equivalent of one theoretical plate height was 14.0 mum for 1 x 10(-4) mol/L DA. The limit of detection was 3.6 x 10(-8) mol/L and the linear range was extended from 5 x 10(-7) mol/L to 1 x 10(-4) mol/L for DA. 1 x 10(-4) mol/L catechol (CA) and 5 x 10(-5) mol/L DA were also separated completely with R-s = 10.1.

Simultaneous spectrophotometric determination of trace iron (III) and aluminum (III) with hybrid linear analysis

Hybrid linear analysis (HLA) was applied to resolution of overlapping spectra of Fe3+-salicylfluorone and Al3+-salicylfluorone complexes and simultaneous spectrophotometric determination of Fe3+ and Al3+. The absorbance matrix of 7 standard mixtures at 41 measuring points ranged from the wavelength of 550 nm to 630 nm was used for calibration. To avoid the effect of interaction between the two components on the determination, the column vector of K matrix obtained from the standard mixtures with least squares was used as the pure spectrum of component. The recoveries of the two elements for the analysis of the synthetic samples were 93.3% similar to 107.5% in the range of the concentration ratio of Fe3+:Al3+ = 10:1 to 1:8. Comparing with the partial least squares (PIS) model, the HLA method was simple, accuracy and precise.

玉米抗低温助长剂田间试验研究

为防御东北玉米低温冷害，研制了一种新型的玉米抗低温助长剂，其抗低温效果已为人工温控试 验所证实。本项研究采用分期播种、地理播种和田间多处理对比试验方法，检验该化学制剂在影响玉米 发育、生物量及产量性状方面的实用效果，并探求其适宜的浓度配比和喷施期次。研究结果表明，该制 剂具有促生长、促早熟和使作物高产的性能，可防御延迟型冷害。施用时以１：４００倍液和在营养生长期 内两次喷施为佳．

Voltammetric behavior of tetracine on glassy garbon electrode and its application

The anodic voltammetric behavior of anaesthetic tetracine and its application were studied. In 0.1 mol/L HClO4 solution, the potential of anodic peak for tetracine is 1.04 V(vs. Ag/AgCl) at a glassy carbon electrode. A linear relationship between the peak height and the concentration of tetracine in the range of 5 x 10(-4) similar to 1 x 10(-1) g/L was obtained. The peak current decreases with the decreasing acidity of the solution. the mehtod has been used for the direct determination of tetracine in injections. The average recoveries of tetracine in urine samples were 98.5%. The mechanism of the electrode reaction was also discussed.

Water soluble polyaniline and its blend films prepared by aqueous solution casting

Polyaniline (PAn) was doped with phosphonic acid containing hydrophilic tails. The solubility of the doped PAn in water was controlled by changing the length of hydrophilic chain in the dopant. When poly(ethylene glycol) monomethyl ether (PEGME) with molecular weight M-w = 550 was used as the hydrophilic chain of the dopant, the doped PAn was entirely soluble in water. The film cast from aqueous solution showed good electrochemical redox reversibility, Aqueous solution blending of PAn with poly(ethylene glycol) (PEG, M-w = 20 000) and poly(N-vinyl pyrrolidone) (PVP, M-w = 360 000) was achieved. Percolation threshold of the composite film was lower than 3 wt.%. Electrical conductivity of the composite film was in the range of 10(-1)-10(-5) S cm(-1), depending on molecular weight of the acid and the content of PAn in the composite. (C) 1999 Elsevier Science Ltd. All rights reserved.

The influence of bond valence on bond covalency in RMn2O5 (R=La, Pr, Nd, Sm, Eu)

The relationship between bond valence and bond covalency in RMn2O5 (R = La, Pr, Nd, Sm, Eu) has been investigated by a semiempirical method. This method is the generalization of the dielectric description theory of Phillips, Van Vechten, Levine and Tanaka scheme. The results indicate that larger valences usually result in higher bond covalencies, in good agreement with the point that the excess charge in the bonding region is the origin of formation of bond covalency. Other factors, such as oxidation state of elements, only make a small contribution to bond covalency.

A new dinuclear molybdenum(V)-sulfur complex containing citrate ligand: synthesis and characterization of K2.5Na2NH4[Mo2O2S2(cit)(2)].5H(2)O

The complex, K2.5Na2NH4[Mo2O2S2(cit)(2)]. 5H(2)O (1), was obtained by crystallization from a solution of (NH4)(2)MoS4, potassium citrate (K(3)cit) and hydroxyl sodium in methanol and water under an atmosphere of pure nitrogen at ambient temperature. The crystals are triclinic, space group , a = 7.376 (3)Angstrom, b = 14.620 (2) Angstrom, c = 14.661 (1) Angstrom, alpha = 71.10 (1)degrees, beta = 81.77 (1)degrees, gamma = 78.27(2)degrees, R = 0.0584 for 2545 observed (I > 2 sigma (I)) reflections. Single crystal structure analysis reveals that citrate ligand coordinated to molybdenum atom through two carboxylato oxygens and one deprotonated hydroxyl oxygen together with two bridging sulfur atoms and a terminal oxygen atom completes distorted coordination octahedron around each molybdenum atom. Principal dimensions are: Mo = O-t, 1.707 Angstrom (av); Mo-S-b, 2.341 Angstrom (av); Mo-O-(hydroxyl), 2.021 Angstrom (av); Mo-O(alpha-carboxyl), 2.1290 Angstrom (av) and Mo-O(beta-carboxyl), 2.268(av) Angstrom. IR spectrum is in agreement with the structure.

弱极化区电极反应动力学分析

弱极化区电极反应动力学分析邱德瑜糜天英（中国科学院长春应用化学研究所长春１３００２２）盛桂云（长春工业高等专科学校长春１３００２１）关键词弱极化区非活化极化β′值的变化中图分类号６４６．５４在弱极化区，对于非活化控制的电极反应过程，βａ、βｃ是ΔＥ的…

环戊二烯类有机金属含硫族化学的新进展

本文系统地综述了环戊二烯类有机过渡金属含硫族（Ｓ，Ｓｅ，Ｔｅ）化学领域的研究现状和进展。

PP/TAIC/PE共混体系的辐射增强相界面反应研究

研究了PP/TAIC(三烯丙基异腈脲酸酯)/PE共混体系的辐射增强相界面反应。应用SEM、DDV对共混体系的形态结构和相容性进行了表征,发现多官能团单体TAIC对PP/PE体系有较好的辐射增强作用,共混物的力学性能得到改善。

K+ sensors based on supported alkanethiol/phospholipid bilayers

A novel kind of K+ sensor with valinomycin-incorporated bilayers supported on a gold electrode consisting of self-assembled alkanethiol monolayers (SAMs) and a lipid monolayer has been fabricated successfully. The lipid monolayer is deposited on the alkylated surface of the first alkanethiol monolayer through three different methods, such as the Langmuir-Blodgett (LB) technique, painted method and painted-frozen method. The response of K + sensors produced by a painted or painted-frozen lipid monolayer on an alkanethiol alkylated gold electrode is larger than that by the LB method, which is due to the difference in fluidity of the three kinds of bilayers. Selectivity coefficients KK+, Na+, KK+, Li+, KK+, Ca2+ and KK+, Mg2+ are 10(-4), 10(-4), 2 x 10(-5) and 3 x 10(-5) respectively, and there is no obvious difference among different fabricating methods. A linear response toward the potassium ion was found in the range from 10(-1) M to 10(-5) M with the detection limit of 10(-6) M. The sensor has a slope of 60 mV per decade. Meanwhile, the longevity of the sensor was improved obviously for at least two months at about -10 degrees C. The higher stability shows the possibility to fabricate a practical biosensor.

卟啉LB膜的分子取向,形貌和膜厚度研究

研究了５，１０，１５，２０－四（对－山嵛酸乙酯－α－氧代苯基）卟啉分子在气液界面的成膜性，制备了该化合物的多层ＬＢ膜，研究了分子中不同的基团在ＬＢ膜中的取向，观测了ＬＢ膜的形貌和厚度。利用偏振ＵＶ－Ｖｉｓ和偏振ＦＴ－ＩＲ谱测定了分子内卟啉环和脂链取代基的取向，结果表明卟啉环面法线和脂链轴线与载片法线间的夹角分别为３７°和２７°。利用ＴＥＭ观测了ＬＢ膜的形貌和厚度，结果表明ＬＢ膜表面均匀，单层厚度大约为２．０ｎｍ，该结果与低角Ｘ射线测量结果相一致

十二烷基磺酸钠-水体系相性质的红外光谱

考察了２０％十二烷基磺酸钠（ＳＤＳ）－水体系在不同状态下的红外光谱，通过特征谱带频率的变化，观察到体系能以烷基链堆积方式不同的两种凝聚胶状态存在，确定了体系由凝聚胶相到液晶相的转变温度为４７℃，相应的逆相变温度为３５℃，并讨论了不同相态中的分子构象变化以及水分子对十二烷基磺酸钠分子构象的影响。

含金鸡钠碱的光活性聚合物2.含辛可宁的两亲单体及其两亲聚合物

通过两亲单体２－丙烯酰胺基烷磺酸（ＡＭＣｎＳ）与辛可宁（ＣＮ）成盐后再聚合，或ＡＭＣｎＳ聚合成梳型两亲聚合物后再与ＣＮ成盐，可获得含辛可宁的两亲聚合物。ＡＭＣｎＳ－ＣＮ盐及其相应的两亲聚合物（当ｎ＝６或１６时）具有比ＣＮ好得多的溶解性，易溶于氯仿、ＴＨＦ、乙醇、ＤＭＦ和ＤＭＳＯ等极性不同的溶剂。ＡＭＣｎＳ－ＣＮ盐在乙醇／氯仿（Ｖ／Ｖ＝１／２）中比旋光度等于辛可宁的比旋光度与辛可宁在盐中重量百分数的乘积，而相应两亲聚合物的比旋光度则不能用相似公式进行计算，说明聚合物主链对辛可宁单元的旋光性有重要影响。含ＣＮ的两亲聚合物与ＰＡＭＣ１６Ｓ相似，在乙醇中显示聚电解质的典型特性