Electrochemical generation of mercury cold vapor and its in-situ trapping in gold-covered graphite tube atomizers

The combination of more efficient flow-through electrochemical mercury cold vapor generation with its in-situ trapping in a graphite tube atomizer is described. This coupled technique has been optimized to attain the maximum sensitivity for Hg determination and to minimize the limits of detection and determination. A laboratory constructed thin-layer flow-through cell with a platinum cathode served as the cold vapor generator. Various cathode arrangements with different active surface areas were tested. Automated sampling equipment for the graphite atomizer with an untreated fused silica capillary was used for the introduction of the mercury vapor. The inner surface of the graphite tube was covered with a gold foil placed against the sampling hole.     

热塑性塑料与液晶共聚酯的原位复合

采用合成的四元液晶共聚酯ＢＰ－ＬＣＰ和ＢＰＭ－ＬＣＰ分别不同的配比与聚碳酸酯、聚对苯二甲酸丁二酯进行原位复合，对原位合物的流变性能和微观结构形态进行研究，并且探讨了液晶共聚酯与基体的相匹配关系，对原位复合的效果作了评价。     

一个热致液晶高分子－高聚物复合体系的粘度函数

一个热致液晶高分子－高聚物复合体系的粘度函数益小苏，赵高明，王惠民（浙江大学高分子科学与工程学系杭州３１００２７）关键词热致液晶高分子，原位复合，流动模型，粘度函数国内外对热致液晶高分子材料（ＴＬＣＰ）的研究均发现，将少量ＴＬＣＰ加入到树脂基体中能有...     

Crystalline Morphology and Crystallization Characteristics of In-situ Blends of Anionic Polyamide 6 with Noncrystallizable Semiaromatic Polyamide Copolymer

A noncrystallizable semiaromatic polyamide copolymer(NSAP) was dissolved in molten caprolactam, and PA6/NSAP blends were produced in-situ via the anionic ring-opening polymerization of caprolactam. The presence of a single loss tangent(tanδ) peak measured by means of dynamic mechanical analysis(DMA) proves the miscibility between PA6 and NSAP in the blends. It was found that there existed drastic changes in the crystallographic form and crystallization kinetics for the in-situ blends, e.g., when 20% NSAP was added, nearly all crystallites existed in the γ form and the crystallization could hardly occur upon cooling even at a rate of 2.5 ℃/min. Moreover, cold crystallization appears during the subsequent heating, and its melting point is 40 ℃ lower than that of the virgin system. On the other hand, the size of the spherulites only decreases modestly. It is suggested that the introduction of irregular stiff segments originated from NSAP into PA6 macromolecule chain, which resulted from transamidation during the polymerization play a dominant role in the drastic change of crystallization kinetics and the resultant morphology of the in-situ blends.     

In-situ pH Measurement at the Electrode/Solution Interface

ElectrochemicaldepositionoffunctionalceramiccoatingshasrecentlyattTactedconsiderableattention'-3becauseofavarietyofadvantagesofthemethodofthecoatingfabrication,suchasalowprocesstemPeratUre,theabilitytodepositonporousorcomplexshaPesofsubstrae,thesimPlecontrolofdepositthickness.Themechanismofelectrodepositionforfunctionalceramicsontothesubstr8tehasnotbeenfiJllyclarifiedatpresent.ltwasgenerallygUessed"'thattheelectrochemicalreactionsontheelectrodesurfacemaycauseapHchangeatthecathode/solutionint…     

Electrochromatography in packed tubes using 1.5 to 50 μm silica gels and ODS bonded silica gels

Summary Electrochromatography (that is HPLC where the eluent is driven along the column by electro-osmosis using fields of up to 100 kV m⁻¹) promises plate efficiencies for HPLC which are comparable to those attained in capillary gas chromatography, but this requires that narrow-bore columns can be successfully packed with submicron particles. This paper demonstrates that we have now moved a considerable distance towards this goal. We show (1) that, following theory, there is no evidence of any reduction in electroosmotic velocity in columns packed with particles down to 1.5 μm diameter, (2) that reduced plate heights as low as unity are attainable for unretained solutes using both slurrypacked and drawn-packed columns 30 to 200 μm bore and up to 1 m long when packed with conventional 3 and 5 μm silica gels or with 1.5 μm impermeable silica spheres, (3) that columns driven electrically show higher plate efficiencies than identical columns driven by pressure, and (4) that 100,000 plate HPLC separations can be achieved in relatively short times of 30 minutes using in situ derivatised drawn packed capillaries containing 3 and 5 μm ODS-silica gels.     

聚苯胺的图形化沉积

自1976年发现第一个有机聚合物聚乙炔掺杂后具有类似金属的导电性以来，先后发现了聚吡咯、聚噻吩和聚苯胺(PAn)等导电聚合物，其中聚苯胺以其合成方法简单、稳定性好、较高的电导率及良好的电化学性能等被预言为是最有应用前景的导电高分子材料之一。近年来，随着导电聚合物研究的广泛开展和不断深入，     

原位插层聚合法制备聚丙烯酰胺/α-磷酸锆纳米复合材料及其结构表征

聚合物／层状无机物纳米复合材料因具有常规复合材料所没有的结构、形态及较常规聚合物基复合材料更优异的性能而引起人们的广泛关注．α-磷酸锆（α-ZrP）作为一种合成的结构规整的层状无机物，其离子交换容量（600mmol／100g）是粘土的6倍，并具有长径比可控和粒子尺寸分布较窄等特点，是制备聚合物／层状无机物纳米复合材料的优良基体．以往的研究工作主要集中于金属氧化物／α-ZrP层柱材料和聚电解质膜两类复合材料，有关聚合物／α-ZrP插层复合材料的研究报道较少．聚丙烯酰胺（PAM）是一种具有广泛用途的水溶性高分子，作为聚电解质，     

热致液晶聚合物的可纺性与其在基体树脂中的成纤

热致液晶聚合物的可纺性与其在基体树脂中的成纤何嘉松，张洪志（中国科学院化学研究所工程塑料国家重点实验室北京１０００８０）关键词热致液晶聚合物，熔融可纺性，高分子共混物，原位复合，亚微米增强用热致液晶聚合物（ＴＬＣＰ）对热塑性树脂产生亚微米级增强作用的...     

油酸修饰CuS纳米颗粒的原位合成及其摩擦学性能

利用原位合成法室温下直接在基础油中成功制备了油酸修饰CuS 纳米颗粒, 将其长时间静置, 不会发生纳米颗粒的团聚. TEM 研究表明, 该方法制备的纳米颗粒粒径大约为30 nm. 红外光谱结果表明, 由于油酸的羧基与无机CuS纳米颗粒表面发生了化学吸附,使无机纳米颗粒的表面有一层有机修饰层, 从而增强了其油溶性.摩擦磨损试验结果表明,该添加剂在基础油中能起到抗磨减摩的效果.随着添加剂浓度的增大, 摩擦系数和磨斑直径都呈现下降趋势,当添加剂浓度为0.1%(w)时, 摩擦系数和磨斑直径都达到最小值,但是进一步增加添加剂浓度, 摩擦系数与磨斑直径又都开始增大. SEM 研究结果表明, 油酸修饰CuS 纳米颗粒能起到抗磨减摩作用的原因是因为其有利于在摩擦副表面形成牢固的润滑膜.