聚（2,5—二甲氧基对苯乙炔）的可溶性前聚物合成及表征

研究了合成聚（２，４－二甲氧基对苯乙炔）的有机可溶性前聚物的反应条件与单体转化率和前聚物产率的关系。实验结果表明：ＮａＯＨ是聚合反应的有效引发剂，适宜的反应条件为：单体与ＮａＯＨ摩尔比为１：１，单体浓度０．０５－０．２ｍｏｌ／Ｌ，聚合时间２ｈ，温度低５℃，正己烷、石油醚作为有机提取剂可有效提高前聚物产率。用ＩＲ、ＵＶ－Ｖｉｓ＇＾ＨＮＭＲ，ＴＧＡ和 ＤＳＣ对前聚物进行了表征。     

聚（2，5－二甲氧基对苯乙炔）的可溶性前聚物合成及表征

研究了合成聚（２，５－二甲氧圣对苯乙炔）的有机可溶性前聚物的反应条件与单体转化率和前聚物产率的关系。实验结果表明：ＮａＯＨ是聚合反应的有效引发剂。适宜的反应条件为：单体与ＮａＯＨ摩尔比为１：１，单体浓度０．０５～０．２ｍｏｌ／Ｌ聚合时间２ｈ，温度低于５℃。正已烷、石油醚作为有机提取剂可有效提高前聚物产率，用ＩＲ、ＵＶ－Ｖｉｓ、￣１ＨＮＭＲ、ＴＧＡ和ＤＳＣ对前聚物进行了表征。     

乙烯基聚硅氧烷共聚反应竞聚率的测定及其对复合粒子形态的影响

用Ｆｉｍｅｍａｎ－Ｒｏｓｓ法处理数据，测定了乙烯基聚硅氧烷（ＳＶ）与苯乙烯（ＳＴ）、甲基丙烯酸甲酯（ＭＭＡ）和甲基丙烯酸正丁酯（ｎ－ＢＭＡ）的共聚反应的竞聚率，结果为ｒＳＴ＝１．４５和ｒＳＶ＝１．０８，ｒＭＭＡ＝０．７８和ｒＳＶ＝２．０１，ｒｎ－ＢＭＡ＝０．４６和ｒＳＶ＝３．４９．以含ＳＶ的乳液作为种子进行烯类单体的乳液聚合，单体和ＳＶ共聚反应对复合粒子的形态有很大影响。     

1,4—双（氯甲基）—2—甲氧基—5—壬氧基苯的均聚和共聚研究

以１，４－双（氯甲基）－２，５一二甲基苯（ＢＣＭＤＭＢ）和１，４－双氯甲基－２－甲氧基－５－壬氧基苯（ＢＣＭＭＯＮＯＢ）为单体，采用脱氯化氢法，合成了聚（２，５－二甲基）对亚苯基亚乙烯（ＰＤＭＰＶ）和聚（２－甲氧基－５－壬氧基）对亚苯基亚乙烯（ＰＭＯＮＯＰＶ）；并对ＢＣＭＤＭＢ和ＢＣＭＭＯＮＯＢ的共聚进行了研究。结果表明，适宜的反应条件为：碱与单体的摩尔比为２０∶１，在室温下聚合时间为３０ｈ，碱的ｐＨ＝１４时产率最高。用ＩＲ、１Ｈ－ＮＭＲ、ＵＶ—Ｖｉｓ对聚合物进行了表征。     

液晶基元直接竖挂于主链上的液晶共聚物的研究

合成了含液晶基元的单体，４＋４＇－（对甲氧基－苯甲酰氧基）－苯甲酸氧基］－苯基－甲基丙烯酸酯，以及由此单体与苯乙烯，通过自由基共聚合反应合成了一系列含液晶性和非液晶性两种序列结构的共聚物．采用ＤＳＣ、偏光显微镜和Ｘ－衍射方法研究了共聚物的液晶行为，发现单体和所有的共聚物（除ＣＰ—９外）均有很好的热致液晶性及较宽的液晶态温度范围；随苯乙烯单体单元摩尔百分含量的增加，共聚物的分子量、相转变温度和热失重温度基本上呈下降趋势．通讯联系人０．ｓｇ／ｄｌ的溶液，于４０ｏＣ用乌氏粘度计测定．ｌ·２单体合成合成路线如下：化合物Ｉ、１１、Ｉｌｌ和ＩＶ的制备按文献ｌ’］的方法进行．化合物１、１１、Ｉｌｌ和ＩＶ经元素分析、‘Ｈ—ＮＭＲ和ＭＳ等表征，结果与其化学结构～致．１．３聚合物的合成聚合反应和共聚物结构式表示如下：按单体（ＩＶ）与苯乙烯不同摩尔比，以ＤＭＦ为溶剂，ＡＩＢＮ为引发剂（相当于单体摩尔数的０．５０）．通过封管聚合，在６０ｏＣ水浴中反应３６ｈ，升温至７０ｏＣ反应１２ｈ，抽滤，用ＤＭＦ和甲醇洗，真空干燥．２结果与讨论２．ｌ含液晶基元的单体（Ｉ）化合物１、１１、Ｉｌｌ和ＩＶ经测试分析结果与其化学结构一致．由表１可见，单体?     

乙基基聚硅氧烷共聚反应竞聚率的测定及其对复合粒子形态的影响

用Ｆｉｍｅｍａｎ－Ｒｏｓｓ法处理数据，测定了乙烯基聚硅氧烷与苯乙烯，甲基丙烯酸甲酯和甲基丙烯酸正丁酯的共聚反应的竞聚率，结果为ｓｔ＝１，４５和ｒｓｖ＝１．０８，ｒＭＭＡ＝０．７８和ｒｓｖ＝２．１，ｒａ－ＢＭＡ＝０．４６和ｒｓｖ＝３．４９。以含ＳＶ的乳液作为种子进行烯类单体的乳液聚合，单体和ＳＶ共聚反应对复合粒的形态有很大影响。     

头孢噻甲羧肟的伏安行为及其单扫描极谱法测定

以多种电化学手段研究了头孢噻甲羧肟的伏安行为。在磷酸盐缓冲溶液中，ＣＴＤ产生２个不可逆吸附还原波，峰电位分别为－０．６５Ｖ和－１．２０Ｖ。分别有１个电子与２个电子和１个质子参与了峰１与峰２的电极过程。探讨了电极反应机理。     

影响苯胺电化学计量聚合因素的探讨

本文对影响苯胺电化学计量聚合的因素进行了探讨，这些因素包括：电化学聚合方法、电极电位（Ｅ）、电流密度（Ｉ），以及苯胺单体和酸溶液的浓度等，实验结果表明，最合适的聚合方法为恒电流法，其条件为：电极电位不大于０．７０Ｖ（ｖｓ．ＳＣＥ）聚合电流密度（Ｉ）约为０．０５ｍＡ／ｃｍ＾２，苯胺单体浓度为１．１ｍｏｌ／Ｌ，酸（ＨＣｌ）的浓度则为２．２ｍｏｌ／Ｌ     

元素分析法测定苯乙烯和丙烯酸－β－羟乙酯竞聚率的误差分析

一对单体，可查到非常多数值不同的竞聚率文献值，说明无论从精度和准确性来说，竞聚率的测定和求算都可能产生很大误差。本文在单体敏感点组成进行实验，用元素分析法测定共聚物组成，用Ｅｒｒｏｒ－ｉｎ－ＶａｒｉａｂｌｅＭｅｔｈｏｄ（ＥＶＭ）［１］法计算苯乙烯（Ｓｔ，Ｍ１）和丙烯酸－β－羟乙酯（ＨＥＡ，Ｍ２）竞聚率，分析全过程的误差来源和大小。     

同步导数荧光法同时测定3种维生素B

研究了维生素Ｂ１、Ｂ２和Ｂ６（分别记为ＶＢ１、ＶＢ２和ＶＢ６）的同步导数荧光分析法，发现在ｐＨ＝７的缓冲溶液中，以△λ＝２０ｎｍ进行同步扫描并取一阶导数时所得的３个同步导数荧光峰（以发射波长表示）分别位于３９７ｎｍ、４７０ｎｍ、和３３４ｎｍ，可同时分别定量测定ＶＢ１、ＶＢ２和ＶＢ６。混合样品无需分离，方法简单、快速。ＶＢ１、ＶＢ２和ＶＢ６的工作曲线线性范围分别为０～４ｍｇ／Ｌ，０～５ｍｇ／Ｌ和０～７ｍｇ／Ｌ。     

双锰卟啉应用于钼酸根电位传感器的研究

以[MnT(p-CH3)PP]2O为活性物质、以o-NPOE为增塑剂PVC膜制成的新型高效电位型传感器来测定MoO42-离子浓度。该电极具有线性能斯特斜率为30.5的响应特征,其工作浓度范围为2.1×10-6~1.0×10-1mol/L,pH范围为5.0~12.5,响应时间不超过15 s,对常见干扰离子有较高的选择性,并被应用于实际样品中MoO42-含量的测定。     

Electrochemical studies on the composition,stabilities and thermodynamics of Zn+2, Cd+2 and Pb+2 complexes with methylene bis thio acetic acid

Potentiometric and conductometric studies on the zinc, cadmium, lead—methylene bis thio acetic acid system in aqueous media reveal the formation of 1:1 and 1:2 (M:L) complexes in thepH range 3.4–5.1. Their stability constants have been determined at 20°, 30° and 40 °C by applyingCalvin andMelchior's extension ofBjerrum's method. The overall changes in thermodynamic function H, G and S accompanying complexation have been evaluated at 30 °C.

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Elektrochemische Untersuchungen über Zusammensetzung, Stabilität und Thermodynamik von Zn(II)-, Cd(II)- und Pb(II)-Komplexen mit Methylen-bisthioessigsäure

Zusammenfassung Potentiometrische und konduktometrische Untersuchungen an Zink-, Cadmium- und Blei-Methylen-bis-thioessigsäure-Systemen in wäßrigem Medium zeigten die Bildung von 1:1 und 1:2 (M:L)-Komplexen impH-Bereich 3,4–5,1. Die Stabilitätskonstanten wurden bei 20°, 30° und 40 °C mittels derCalvin-Melchior-Methode (erweiterteBjerrum-Methode) bestimmt. Die thermodynamischen Parameter H, G und S der Komplexierung wurden für 30 °C ermittelt.

     

钯膜电极在电位滴定中的应用研究

报道钯膜电极在电位滴定中的应用。研究证明,它适用于化学分析法的五种类型的滴定,如沉淀滴定、氧化－还原滴定、酸碱滴定、非水溶剂滴定和某些形成络合物反应的滴定中作为指示电极,所获结果与化学标准方法吻合。     

还原溶出计时电位法测定水中痕量锰

提出了在pH 8.8的H3BO3-Na2B4O7介质中,用还原溶出计时电位法测定水中痕量锰的方法。锰的检出限为0.5ng·ml-1,相对标准偏差为4.5％,线性范围为0.5～25ng·ml-1。采用标准曲线法对五份不同浓度的水样进行了测定,结果与原子吸收法相符。     

Ammonia Electrode Performance in Deuterium Oxide Solutions

Abstract

Response characteristics of the ammonia gassensing membrane electrode have been evaluated in deuterium oxide solutions. Results indicate no significant differences in electrode slope, recovery time, and standard deviation of the fit for the calibration line. Only slight differences in response times, limit of detection, baseline potential and position of the calibration line have been found. Overall, steady-state and dynamic measurements in deuterium oxide solutions are possible with this electrode.     

The potentiometric performances of cyclotetrahydroxysiloxane containing ferrocenyl moiety as an anion-selective membrane electrode

A test electrode based on cyclotetrasiloxane containing ferrocenyl, hydroxide and amine moiety exhibits very good potentiometric performance toward anions. Especially, acetate ion shows non-Hofmeister behavior on selectivity. The addition of the tetraalkylammonium salt provides lipophilic cationic sites within the membrane and enhances the response to more lipophilic anions. As expected, potentiometric performances of slopes and detection limits for the most of lipophilic anions, such as ClO₄⁻ and SCN⁻, are the most enhanced. However, the response to acetate ion was significantly decreased. In our knowledge, this is the first report that cyclic siloxane containing functional groups such as ferrocenyl moiety and hydroxyl group shows possible usage as a neutral carrier for an anion sensor.     

Solid-state potentiometric gas sensors—current status and future trends

The development of potentiometric sensors for monitoring environmental gases has become a well-established direction in sensor technology. Various types of potentiometric sensors employing solid electrolytes for in situ measurements of such gases as oxygen, hydrogen, carbon dioxide, sulfur oxides, carbon monoxide, nitrogen oxides, and hydrocarbons are reviewed. Particular concern was given to the CO₂ potentiometric sensor which is an example of successful commercial application. The construction details, working mechanism, and performance of different types of potentiometric gas sensors are given. Special emphasis is given for the mixed-potential electrodes, which seems to be the principal direction for the future research and development of the sensor science and technology. Additionally, the future use of potentiometric sensors for the detection of other environmental gases is discussed.     

Fully Automatic Potentiometric Titrations [New analytical methods (9)]

Fully automatic titration systems consist of at least two units: the sample-changing system and the measuring system, the latter including addition of the reagent. These systems are preferably coupled to a computer. The possibilities of fully automatic titration can be best utilized if the sources of error are taken into account and the evaluation procedure optimal for the specific analysis is selected.     

流动注射电位滴定研究：氟化物沉淀滴定测锂

设计制作了一种简便的梯度混合室,并考察了其性能,试验结果证实了此混合室的合理性和有效性.用此混合室建立了流动注射电位滴定测锂的新方法,载流为1×10~(-5)～1×10~(-4)mol·L~(-1)的F~乙醇-水(9 1)溶液,流速4.2ml·min~(-1),混合室体积400μl,进样体积120μl,分析速度60样·h~(-1),检出范围取决于载流中滴定剂的浓度,方法用于卤水中锂的测定,结果令人满意.     

Ionic Liquids Modify the Performance of Carbon Based Potentiometric Sensors

A new type of potentiometric sensor based on a recently constructed carbon ionic liquid electrode (CILE) is described. Two kinds of ionic liquids, i.e., N‐octylpyridinium hexafluorophosphate (OPFP) and 1‐butyl‐3‐methylimidazoluim hexafluorophosphate (BMFP) were tested as binder for construction of the carbon composite electrode. The characteristics of these electrodes as potentiometric sensors were evaluated and compared with those of the traditional carbon paste electrode (CPE). The results indicate that potentiometric sensors constructed with ionic liquid show an increase in performance in terms of Nernstian slope, selectivity, response time, and response stability compared to CPE.