苯乙烯在炭黑表面的阴离子接枝聚合研究

利用正丁基锂（ｎ－ＢｕＬｉ）与炭黑（ＣＢ）表面含氧基团反应制得了表面含－ＯＬｉ基团的反应型炭黑，以该炭黑与聚氧乙烯－聚氧丙烯－聚苯乙烯（ＰＥＯ－ＰＰＯ－ＰＳ）多嵌段聚合物组成的阴离子引发体系作活性中心，研究了苯乙烯在炭黑表面的阴离子接枝聚合。ＦＴ－ＩＲ，ＴＥＭ和ＤＳＣ分析表明在接枝炭黑表面存在苯乙烯的聚合物。接枝炭黑在甲苯中有良好的分散稳定性。     

乙烯基单体在炭黑表面上的接枝聚合

讨论了分别在铈离子体系，正丁基锂体系，过渡金属离子乙酰丙酮铜（Ⅱ）以及焦磷酸络锰（Ⅲ）体系的作用下，炭黑与乙烯基单体的接枝聚合．研究了引发剂浓度、单体浓度、反应时间对接枝聚合反应的影响．利用ＦＴ ＩＲ分析确证了炭黑表面的接枝反应，利用ＴＥＭ表征了接枝炭黑的形态．结果表明，在所研究的多种炭黑表面接枝聚合体系中，正丁基锂体系的接枝率最高，可达２００％．而各种氧化还原体素的接枝率只能达到３０％左右．表面接枝后的炭黑在介质中的分散稳定性明显改善．     

聚丙烯酸酯接枝炭黑的合成,表征及其应用

探讨聚丙烯酸酯接枝炭黑的合成条件及其影响因素。用红外光谱和元素分析对接枝物进行了表征,通过ζ－电位法,透光率和ＳＥＭ研究了接枝炭黑的分散稳定性。接枝炭黑分散于水性无皂涂料中形成黑色涂料具有良好的综合性。     

炭黑表面含氧量对HDPE—CB复合物导电性能的影响

通过硝酸氧化处理炭黑（CB）,使其表面含氧量（氧元素与碳元素的摩尔百分比）由1．0％（CB1）提高到7．0％（CB2）。分别以CB1和CB2为填料,以高密度聚乙烯（HDPE）为基体,制备了两种导电复合材料。与碳粒子填充极性聚合物相反,表面含氧量高的CB2填充HDPE复合物的渗流阈值低。采用SEM、动态电渗流效应和Payne效应分析了两种炭黑在HDPE中的分散和凝聚特征。结果表明：CB2在HDPE中分散更不均匀,更容易凝聚形成网络。炭黑在非极性HDPE中凝聚形成导电网络的能力随炭黑表面含氧量的增加而提高。     

天然橡胶原位接枝炭黑的分散性研究

采用原位固相接枝方法,使在高温和强剪切作用下降解的天然橡胶接枝到炭黑表面.采用透射电镜(TEM)、原子力显微镜(AFM)等方法观察了接枝前后的炭黑粒子形貌变化,发现未接枝炭黑以微米级的附聚体形式存在,而由于炭黑聚集体被强剪切力部分破坏,接枝炭黑的聚集程度明显减弱,粒子的尺寸减小.采用激光光散射粒度仪对接枝前后炭黑的粒度进行分析,接枝炭黑的体积平均粒径为164 nm,远小于测得的原炭黑的粒径797 nm.采用沉降法、透光率法及zeta电位测量研究了接枝改性对炭黑在溶剂中的分散性及分散稳定性的影响,结果表明,接枝炭黑在接枝分子的溶剂中的分散性变好,分散稳定性提高.     

高效液相色谱法同时测定吡虫啉中间体

建立了用高效液相色谱法同时测定农药吡虫啉中间体２－氯－５－甲基吡啶６ ２－氯－５－氯甲基吡啶含量的方法。在此条件下,２－氯－５－甲基吡啶、２－氯－５－氯甲基吡啶以及杂质等均能较好分离,峰面积与浓度具有良好的线性关系,相关系数分别为０．９９９６和９．９９９７;平均回收率分别为１００．０％和９９．７１％。     

有机溶剂中微量水的荷移光谱法测定

研究了氯冉酸与有机溶剂中水的反应，确定了反应条件，氯冉酸与水的络合物的最大吸收波长为530nm。在乙醇、甲醇，正丙醇，异丙醇、正丁醇，正庚醇，正己醇溶剂中，水的含量分别在0－5％（V／V）或0－8％（V／V）范围内呈线性关系，相关系数为0．998或0．999；该方法重现性好，灵敏度高，操作简单，用于测定乙醇中微量水的含量，与标准值相符；加入回收法测得甲醇中水的回收率分别为98％－103％，结果令人满意。     

水溶性分散剂的合成及其性能研究

合成了苯乙烯－顺丁烯二酸酐共聚型水溶性分解剂，并讨论了这种分散剂对导电粉及炭黑等难分散颜料的分散稳定性作用。结果表明，在水介质中，该发散剂能明显改善导电粉和炭黑颜料的分散稳定性。     

LDPE／CPE／炭黑三相复合导电体系的亚微形态和导电性能

对ＬＤＰＥ／ＣＰＥ／炭黑三相复合导电体系的亚微形态和导电性能进行了研究。实验发现,该体系的亚微形态在共混比ＬＤＰＥ／ＣＰＥ大于和小于５０／５０时为典型的“海－岛”结构,在５０／５０时,为两相连续交错“互锁”结构;在共混比大于５０／５０时,ＬＤＰＥ／ＣＰＥ炭黑复合体系的导电性能较单一的ＬＰＤＰＥ树脂与炭黑复合体系的高２－５个数量级。     

导数恒基体强度同步荧光分析法同时测定光谱严重重叠的1-氯蒽和9-溴蒽

通过选择适合测定路径,应用恒基体强度同步及荧光法同时测定了两种光谱严重重叠的蒽衍生物1－氯蒽和9－溴蒽。混合物中1－氯蒽和9－溴蒽不必预分离就能直接同时测定。在混合物中1－氯蒽和9－溴蒽的回收率分别为83．5％－94．0％,90．0％－94．0％,检出限分别为0．69μg/L,10μg/L。     

Determination of iodine in organic compounds employing oxygen flask combustion and mercurimetric titration

Iodine in iodine-containing organic compounds is determined by oxygen flask combustion followed by mercurimetric titration. The method is the same as that used in a collaborative study on the determination of bromine and chlorine with the exception that hydrazine is used as the reducing agent instead of alkaline peroxide and the type of buret to be used for the titration is specified. Accuracy and precision are well within the acceptable limits.     

Heat-Resistant Polymer-Grafted Carbon Black: Grafting of Poly(Organophosphazenes) onto Carbon Black Surface

Abstract

The grafting of poly(organophosphazenes) onto carbon black surface by the reaction of poly(dichlorophosphazene) (PDCP) with carbon black having sodium phenoxide groups was investigated. PDCP was prepared by the ring-opening polymerization of hexachlorocyclotriphos-phazene in solution using sulfamic acid as a catalyst. The introduction of sodium phenoxide groups onto carbon black was achieved by treatment of phenolic hydroxyl groups on the surface with sodium hydroxide in methanol. Poly(diphenoxyphosphazene) (PDPP) was successfully grafted onto carbon black by the reaction of PDCP with sodium phenoxide groups introduced onto the surface followed by the replacement of chlorine atoms in PDCP with phenoxy groups. The percentage of grafting onto carbon black increased to 206% at 30°C after 12 h. It was found that only 1.4% of sodium phenoxide groups on carbon black surface was used for the grafting of PDCP because of the blocking of the surface by grafted polymer chains. Poly(diaminophenylphosphazene) and poly-(diethoxyphosphazene) were also grafted onto carbon black surface by the treatment of PDCP-grafted carbon black with aniline and sodium ethoxide, respectively. Poly(organophosphazenes)-grafted carbon blacks produced stable colloidal dispersions in good solvents for grafted polymers. Furthermore, thermogravimetric analysis indicated that poly-(organophosphazenes)-grafted carbon blacks were stable in air about 300°C.     

Simplification of the mercurimetric procedure for organohalogen determination

The mercurimetric method for organohalogen determination described in 1959 can be further simplified by omitting the boiling process for removal of hydrogen peroxide after combustion of the sample in the oxygen flask. Hydrogen peroxide does not interfere in the mercurimetric titration. Its presence did show certain advantages in the work of other investigators as well as in this present study.     

A Miniaturized Carbon Black‐based Electrochemical Sensor for Chlorine Dioxide Detection in Swimming Pool Water

The recent trend of using sustainable disinfectants in water treatment sector boosted the employment of chlorine dioxide (ClO₂) as green disinfectant. Indeed, this disinfectant is characterised by several attractive features such as the working capability in a wide range of pH and the absence of harmful by‐products. These characteristics confer to chlorine dioxide a prominent position between the disinfectants, thus analytical tools for on‐site detection are needed to customize the water treatment. Herein, we described the development of an innovative and cost‐effective carbon black modified screen‐printed electrode for amperometric quantification of chlorine dioxide in standard solution and in swimming pool water. The carbon black as working electrode nanomodifier allowed for the detection of chlorine dioxide at low applied potential, with linear range of 0.05–20 ppm, and a detection limit of 0.01 ppm. The matrix effect evaluation as well as the recovery study demonstrated the capability of this sensor for a cost‐effective detection of chlorine dioxide in swimming pool water, paving the way for the use of miniaturised electrochemical sensors in water treatment field.     

QuEChERS-气相色谱-串联质谱法测定枸杞中农药残留

建立了QuEChERS-气相色谱-串联质谱法测定枸杞中农药残留的分析方法。样品经乙腈提取，采用乙二胺-N-丙基硅烷（PSA）、C18和石墨化炭黑（GCB）3种吸附剂净化，在多反应监测模式（MRM）下进行检测，基质外标法定量。结果显示，检测项目在5~500 μg/L范围内呈良好线性（R²>0.99），在3个添加水平下测得回收率为71.5%~109.7%，相对标准偏差（RSD）为1.94%~9.87%（n=6）。该方法灵敏度高、净化效果好，可同时快速检测有机磷类、有机氯类农药。     

Iodometric microdetermination of chlorine and bromine in some highly halogenated organic compounds

Summary Highly halogenated organic compounds are combusted in a oxygen flask using water as absorbant in the case of chlorine and 0.05% hydrogen peroxide in the case of bromine. The halogenide ion formed is determined by an iodometric procedure. Results showed an average error of ± 0.1% for Cl and ± 0.2% for Br. They are in close agreement with those obtained by a mercurimetric titration. The iodometric titration is to be preferred because of simplicity and rapidity

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Jodometrische Mikrobestimmung von Chlor und Brom in einigen hochhalogenisierten organischen Verbindungen

Zusammenfassung Die Verbindung wird im Sauerstoffkolben verbrannt, wobei Wasser (Cl) bzw. 0,05%ige Wasserstoffperoxidlösung (Br) als Absorptionsmittel verwendet werden. Die gebildeten Halogenide werden jodometrisch bestimmt. Der durchschnittliche Fehler beträgt ± 0,1% (Cl) bzw. ± 0,2% (Br). Die Ergebnisse stimmen gut mit mercurimetrisch erhaltenen überein. Die jodometrische Titration ist wegen der einfachen und schnellen Durchführbarkeit vorzuziehen.

     

液相色谱-质谱法分析黑碳的分子标志物——苯多羧酸和硝基苯多羧酸

苯多羧酸法是定量检测黑碳和溶解态黑碳的重要分子标志物法,其中苯多羧酸和硝基苯多羧酸的分离和定量是关键环节。本文建立了苯多羧酸和硝基苯多羧酸的液相色谱-质谱分析方法,利用质谱的定性能力解决了部分苯多羧酸和硝基苯多羧酸化合物在缺乏标准品情况下的定性问题。用Phenomenex Synergi Polar RP分离柱,柱温为35 ℃,流动相为0.5%(体积分数)甲酸水溶液和甲醇,流速为0.5 mL/min,梯度洗脱,以电喷雾离子源负离子全扫描和选择扫描模式进行离子阱质谱检测,同时利用串联的二极管阵列检测器采集三维紫外光谱数据。在实际样品检测中,14个含3个及以上羧基的苯多羧酸和硝基苯多羧酸化合物获得良好分离。此方法简化并加快了苯多羧酸法定量黑碳和溶解态黑碳的分析过程,可满足环境样品中黑碳和溶解态黑碳的分析,促进了苯多羧酸法应用的普及。     

利用高压水射流技术制备天然橡胶复合材料

首先利用超声空化作用将炭黑团聚体破碎、切割、分散在水中制得炭黑悬浮液,然后在高速射流场中,炭黑悬浮液被高速射流卷吸到天然胶乳中,在射流边界,由于二者存在极大的速度差,而形成一个湍流混合层,炭黑在湍流拉伸、剪切作用下微观分散到天然胶乳中.结果表明,与传统干法工艺相比,射流工艺可以使炭黑更均匀的分散到天然橡胶基体中.Payne效应结果表明射流工艺减弱了炭黑与炭黑之间的相互作用,增强了炭黑与橡胶之间的相互作用.同时射流工艺制备的复合材料硫化时间变短,硫化程度增加,硫化胶的撕裂强度提高了78%,回弹性提高了20%,DIN磨耗减小了33%.动态力学性能结果表明,射流工艺制备的复合材料在60℃左右具有更低的损耗因子.     

The influence of arrangement of substituents in isomeric chlorobenzenes on their adsorption on graphite

Henry's constants and the heats of adsorption of benzene chloro derivatives on graphitized thermal carbon black were calculated by the semiempirical molecular statistical theory of adsorption. The best agreement between the experimental and calculated data was achieved by introducing corrections for the presence of other chlorine atoms in theortho-positions into the calculation of the atom-atomic potential of the intermolecular interaction of the chlorine atom with the carbon atom of graphite. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 672–676, April, 1999.     

Simple and specific microdetermination of organoiodine via oxygen flask combustion

A rapid, simple, and reliable procedure for specific microdetermination of organoiodine is described. This procedure consists of oxygen flask combustion followed by an argentimetric titration with an iodide ion-selective electrode as indicator. Some advantages of this procedure over mercurimetric titration currently used in an AOAC method are detailed.