石墨探针-石墨炉原子吸收光谱法测定人发中痕量镍

石墨探针原子化技术是一种实现等温原子化和改善灵敏行之有效的方法，采用此方法对痕量镍的测定作了一系列条件试验，峰面积与镍浓度在０－２００ｎｇ／ｍＬ范围内呈线性关系，特征量为５１．８３ｐｇ，检出限为８６．８２ｐｇ，相对标准偏差为３．８６％。     

平台石墨炉原子吸收法测定高温镍基合金中砷

研究了基体改进剂，灰化，原子化温度和共存元素的干扰。采用钯作基体改进剂和匹配基体镍后，提高了灵敏度，增强了抗干扰能力。在波长１９７．２ｎｍ处，用平台石墨炉原子吸收法直接测定了高温镍基合金中砷。方法特征是为８８ｐｇ，检出限为０．２７μｇ．ｇ＾－１，相对标准偏差为３．１％－５．１％，回嵋率为８５％－１００％。     

流动注射—氢化物—石墨炉原子吸收光谱法应用研究

本文采用自制的氢化物－石墨炉自动进样器及流动注射仪，直接测定了一些环境试样中的痕量锗，并研究了测定条件，该方法灵敏度高，线性范围宽，操作简单，速度快，耗样量少。特征质量：５．７ｐｇ／０．００４４Ａ；检出限：１．３ｐｇ，测定速度：３０个样／ｈ；回收率：９９．５％－１０４％。     

钯－抗坏血酸基体改进剂石墨炉原子吸收光谱法测定食品中的痕量硒

本文用塞曼效应石墨炉原子吸收法测定食品中的硒，研究了各种基体改进剂对硒信号的改进效应，找出最佳的改进剂钯－抗坏血酸，使硒的灰化和原子化都能达到较高温度，在提高灵敏度，降低干扰方面也取得较好的效果。本方法操作简单、快速，灵敏度高，能有效地测定食品中的痕量硒。方法的回收率在９５．６％～１０４．０％之间，其相对标准偏差为３．０％，检出限为４．８５ｎｇ／ｍＬ。     

氢化物发生石墨炉原子吸收光谱法直接测定高温镍基合金中的硒

在６ｍｏｌ／Ｌ盐酸介质和０．１％ＫＢＨ４条件下，不但能有效地发生硒的氢化物，而且５ｍｇ／ｍｌＮｉ和３ｍｇ／ｍｌＦｅ都不干扰硒的测定。利用涂钯石墨；管作为氢化物的原子化器，直接测定了高温镍基合金中的硒，特征质量为４０ｐｇ，相对标准偏差在６．１％以内，回收率在９７％－１１０％之间。     

阳离子表面活性剂增敏催化光度法测定痕量铬(Ⅵ)

基于存在增敏剂十六烷基三甲基溴化铵,铬（Ⅵ）催化过氧化氢氧化胭脂红酸的反应,拟定了测定痕量铬（Ⅵ）的新催化光度法。本法由于添加了十六烷基三甲基溴化铵,灵敏度提高３．３倍,测定铬（Ⅵ）含量的线性范围为０．００５～０．１６μｇ／ｍＬ,检出限为１．０×１０－３μｇ／ｍＬ,相对标准偏差为０．５％（ｎ＝９）,可用于测定水样中的铬（Ⅵ）。     

钯—抗坏血酸基体改进剂石墨炉原子吸收光谱法测定食品中的痕量硒

本文用塞曼效应石墨炉原子吸收法测定食品中的硒，研究了各种基体改进剂对硒信号的改进效应，找出最佳的改进剂钯－抗坏血酸，使硒的灰化和原子化都能达到较高温度，在提高灵敏度，降低干扰方面也取得较好的效果。本方法操作简单、快速、灵敏度高，能有效地测定食品中的痕量硒。方法的回收率在９５．６％－１０４．０％之间，其相对标准偏差为３．０％，检出限为４．４８５ｎｇ／ｍＬ。     

石墨炉原子吸收法测定植物样品中硼的研究

本文比较了四种石墨和三种基体改进剂对石墨炉法测硼的影响。结果表明，使用涂层石墨管并采用Ｃａ－Ｍｇ－抗坏血酸作基体改进剂，可获得最高的灵敏度和最好的回收率，讨论了硼的最佳工作条件和干扰情况，对植物标准样品进行了测定，所得结果与标准值吻合，植物中硼含量为３４～５３μｇ／ｇ时，方法的相对标准偏差为２．１％～３．８％，检出限为３７８ｐｇ（Ｋ＝３）。     

阳离子表面活性剂增敏催化光度测定痕量铬（Ⅵ）

基于存在增敏剂十六烷基三甲基溴化铵,铬（Ⅵ）催化过氧化氢氧化胭红酸的反应,拟定了测定痕量铬（Ⅵ）的新催化光度法。本法由于添加了十六烷基三甲基溴化铵,灵敏度提高３．３倍,测定铬（Ⅵ）含量的线性范围为０．００５－０．１６μｇ／ｍＬ,检出限为１．０＊１０＾－３ｇ／ｍＬ相对标准偏差为０．５％,可用于测定水样中的铬。     

溶剂萃取石墨炉原子吸收光谱测定盐卤中痕量铷

采用石墨炉原子吸收光谱（ＧＦＡＡＳ）研究盐卤中铷的原子化行为和机理,建立了热解石墨管,ＫＮＯ３－ＮＨ４ＮＯ３基体改进剂,１８－冠－６,溴百里香酚蓝,氯仿萃取分离ＧＦＡＡＳ测定盐卤铷的方法。用于测定盐卤中痕量铷,特征质量１．１×１０＾－１０ｇ／０．００４４,加标回收率８９％￣１１０％;相对标准偏差６．２８％（ｎ＝１３）。     

高分子/石墨复合材料的制备与导电性能的研究进展

介绍了近年来高分子/石墨复合材料制备方法和导电机理的研究进展。通过氧化、插层以及插层后加热可以在石墨碳层上引入极性基团,提高其比表面积,有利于高分子进行插层。用处理后比表面积高的石墨制备复合材料可以降低材料的渗滤值,提高材料的导电性能。复合材料的导电机理可以用渗滤理论来解释。     

Study of the reactivity of chalcogen hexafluorides with graphite

The intercalation reaction of chalcogen hexafluorides, EF₆ (E=S, Se, Te), with graphite was investigated. It occured only under a fluorine atmosphere and first stage intercalation compounds were obtained with TeF₆ or SeF₆, as well as a partial graphite fluorination. SF₆ did not intercalate but catalyzed the complete fluorination of graphite. All compounds were characterized by X-ray diffraction, thermogravimetric analysis, infrared and ¹⁹F NMR spectroscopies. Entities, such as TeF₆ and SeF₆ were identified. Others, such as EF₇⁻, EF₈²⁻, …, and possible SeF_n polymeric forms could exist. In all cases, the presence of fluorinated graphite was found.     

Electrochemical preparation of graphite intercalation compounds containing a cyclic amide, [CF2(CF2SO2)2N]

Graphite intercalation compounds (GICs) containing the cyclo-hexafluoropropane-1,3-bis(sulfonyl)amide anion, [CF₂(CF₂SO₂)₂N]⁻, are prepared for the first time. Stages 2 and 3 GICs are obtained by electrochemical oxidation of graphite in a nitromethane electrolyte. Gallery heights of 0.85-0.86 nm are determined by powder X-ray diffraction, and the intercalate anion orientation within the intercalate galleries is modeled using an energy minimized anion structure. GIC compositions are determined by thermogravimetric, fluorine and nitrogen analyses. The chemical preparation and bifluoride displacement reactions are compared with a GIC containing the linear bis(trifluoromethanesulfonyl)amide anion, [(CF₃SO₂)₂N]⁻.     

石墨烯薄膜的制备和结构表征

采用氧化还原法制备了石墨烯胶状悬浮液, 通过真空抽滤获得了石墨烯薄膜. 利用X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、拉曼(Raman)光谱、粒度分析和扫描探针显微镜(SPM)等研究了石墨烯薄膜制备过程中各阶段产物的晶体结构、粒度及分子光谱特征变化. FTIR分析结果表明, 石墨在氧化过程中结构层键合大量含氧官能团, 还原后结构层表面仍残存有部分稳定的含氧官能团. XRD结果表明, 石墨氧化后衍射峰向小角度偏移、宽化, 原有石墨峰消失. 在成膜过程中氧化石墨烯形成凝聚体,而石墨烯形成絮凝体. 粒度分析和SPM测试分析结果表明, 氧化石墨烯在水中粒径分布呈拖尾峰形, 分布范围较宽. 石墨烯在水中的粒径成单峰分布, 分布范围较窄、对称性较好且平均粒径较小. Raman测试结果表明, 石墨在氧化和还原过程中, D、G峰逐渐宽化, I_D/I_G逐渐增强, 样品无序度增加. 在以上分析的基础上对石墨烯制备过程的结构特征进行了归纳总结.     

Nucleation and growth mechanism for the electropolymerization of aniline on highly oriented pyrolytic graphite at higher potentials

In this work, the nucleation and growth mechanism for the electropolymerization of aniline was investigated at higher potentials on highly oriented pyrolytic graphite by potentiostatic current-time transient and atomic force microscopic (AFM) measurements. The electrochemical data fitted to the theoretical curves for the nucleation and growth suggest that electropolymerization of aniline follows the three-dimensional growth and progressive nucleation mechanism. These results were also compared with the results obtained at lower potentials. The results obtained from transient analysis, at higher potentials, were in good agreement with the results of AFM images. Electronic Publication     

Graphite intercalation compounds with large fluoroanions

Over the past 20 years, a number of relatively large, perfluorinated anions have been found to intercalate into graphite. This review will describe the background, some syntheses and structures of these graphite intercalations compounds (GIC's). The fluoroanion intercalates include perfluoroalkylimides, perfluoroalkylsulfonates, and perfluoroalkylborate esters. Synthetic methods can include either chemical oxidation, for example using K₂MnF₆ in anhydrous or hydrous hydrofluoric acids or electrochemical oxidation. These gallery structures present in these GIC's are larger and more complex than for most previously-known GIC's, and therefore may be important in advancing the known chemistry of graphite. In this review, the relationship of intercalate packing, orientation and conformation is discussed.     

Alkylation on graphite in the absence of Lewis acids

Graphite is introduced as a convenient catalyst for alkylation of aromatic compounds and alcohols by benzyl, tertiary alkyl, and secondary alkyl halides in the absence of strong Lewis acids. Primary alkyl halides are not active under the reaction conditions.     

Platinum Nanosheets Intercalated into Natural and Artificial Graphite Powders

Insertion of sheet-type platinum particles (platinum nanosheets) between graphite layers was achieved by a thermal treatment of a mixture of platinum chloride (IV) and graphite powder (natural graphite or artificial graphite) under 0.3 MPa of chlorine at 723 K, followed by the treatment under 40 kPa of hydrogen pressure. Similar platinum nanosheets, which were 1–3 nm in thickness and 100–500 nm in width and had a number of hexagonal holes and edges with 120° angle, were formed between the layers of both natural graphite or artificial graphite; however, their location in the graphite layers depended on the type of graphite used. A number of platinum nanosheets were observed in the edge region of natural graphite particles which have flat surface. On the other hand, a number of platinum nanosheets were found inside and away from the edge of the artificial graphite particles especially in the vicinity of the cracks. Both the platinum nanosheet-containing artificial and natural graphite samples showed high selectivity to cinnamyl alcohol in cinnamaldehyde hydrogenation under supercritical carbon dioxide conditions, while spherical platinum particles, which were located on the surface of natural and artificial graphite, showed lower selectivity.     

PANI/Ce(OH)3-Pr2O3·3H2O/NanoG复合材料制备与表征

开发了反胶束模板-原位聚合纳米复合法制备聚苯胺(PANI)/Ce(OH)3-Pr2O3·3H2O/石墨纳米薄片(NanoG)纳米复合材料的方法.膨胀石墨在乙醇水溶液中经超声处理制得石墨纳米薄片,以苯胺的氯仿溶液为油相,稀土金属离子Pr3+、Ce3+水溶液为水相,依靠表面活性剂十六烷基三甲基溴化铵(CTAB)自组装形成的反胶束为模板-制备PANI/Ge(OH)3-Pr2O3·3H2O/NanoG复合材料.利用红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)和 X-射线衍射(XRD)对该复合材料进行了表征和分析,研究了其导电性能和热性能.结果表明,PANI/Ce(OH)3-Pr2O3·3H2O/NanoG复合材料各相分散均匀,稀土纳米粒子在体系中以棒状的形态分布.热重分析表明,该复合材料的热稳定性明显提高;导电性研究说明,石墨纳米薄片的特殊的结构(较大的径厚比)对其在聚合物基体中形成导电网络具有重要作用;PANI/Pr2O3-Ce(OH)3/NanoG纳米复合材料的渗滤阀值低于1.0wt%.