NdCl3-FeCl3-石墨层间化合物的合成

采用熔盐交换法成功地合成了ＮｄＣｌ３ＦｅＣｌ３ＧＩＣ, 用ＸＲＤ 技术和Ｘ射线能谱仪（ＥＤＳ） 对其层间结构及各元素的相对含量进行了表征。研究表明, 其结构为２,３ ,４ 阶混合结构,３ 阶ＮｄＣｌ３ 的特征层间距为１－６５３６ ±０－００２４ ｎｍ , 并探讨了稀土氯化物石墨层间化合物的形成机制。     

NdCl3-FeCl3-石墨层间化合物的XPS研究

通过熔盐交换法合成了ＮｄＣｌ３－ＦｅＣｌ３－ＧＩＣ,采用Ｘ射线电子能谱（ＸＰＳ）分析插入剂在石墨层间的存在形式,并测定了试样中Ｎｄ,Ｆｅ,Ｃｌ和Ｃ的相对含量。ＮｄＣｌ３－ＦｅＣｌ３－ＧＩＣ中Ｆｅ２ｐ的结合能为７１１．２０－７１０．３ｅＶ,Ｎｄ３ｄ的结合能为９８３．２０－９８３．０８ｅＶ,并发现Ｆｅ在石墨层ｅ＾３＋,Ｆｅ＾２＋形式存在。     

聚乙烯/石墨层间化合物热降解过程的TG-FTIR研究

将含磷化合物插层石墨层间化合物(GIC)用于聚乙烯(PE)的阻燃,采用氧指数(LOI)方法评价了PE/GIC的阻燃性能,并采用热分析-红外光谱联用技术(TG-FTIR)研究了PE/GIC的热降解过程,探讨了GIC的阻燃机理。研究表明,不同含磷化合物插层GIC阻燃聚乙烯的氧指数有显著差别,其中以多聚磷酸铵-GIC的阻燃效果较好,氧指数较高。TG-FTIR研究结果表明,GIC并未显著影响PE的热降解方式,但由于GIC体积膨胀所发生的氧化还原反应导致部分PE热降解提前并发生热氧化降解,促进了后期成炭的石墨化过程。     

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。     

金属石墨层间化合物的量子化学和热力学研究

采用量子化学密度泛函B3LYP方法,对碱金属、碱土金属和过渡金属石墨层间化合物(A-GIC,AE-GIC和T-GIC)进行计算.从原子净电荷、Mulliken重叠布居和轨道电子数等角度讨论了A-GIC和AE-GIC的电子结构与成键特性,初步阐明了结构与性能的关系.根据计算结果,结合热力学分析,讨论实验上尚未知的过渡金属石墨层间化合物合成的可能性.     

NdCl3-FeCl3-石墨层间化合物的合成及结构模型

通过扫描电子显微镜(SEM)和能谱分析(EDS)研究了NdCl3-FeCl3-石墨层间化合物的微观形貌和元素分布. 结果表明, Nd元素插入石墨层间并形成了NdCl3-FeCl3-石墨层间化合物, 同时发现在石墨中Nd, Fe元素分布均匀. 在此实验基础上, 建立了稀土氯化物(RECl3)插入石墨的结构模型; 依据模型, 计算了RECl3-石墨层间化合物的特征层间距dPP值和间隔能指数, 计算值与实验值吻合较好, 其相对误差约为±2%; 并且发现TbCl3～LuCl3以(001)晶面插入石墨层间时, 其所需间隔能最小, 而LaCl3～GdCl3以(111)晶面为最优取向.     

膨胀石墨制备方法的研究进展

综述了膨胀石墨制备方法的研究现状,重点阐述了两种常用制备方法:（1）以天然鳞片石墨为原料,先经氧化制得可膨胀石墨,再经膨化处理得膨胀石墨;（2）将氧化和膨胀同时进行的爆炸法。分析了不同制备方法的优劣。并对膨胀石墨的制备工艺进行了展望。参考文献48篇。     

增大层间距对天然石墨可逆储锂性能的影响研究

利用石墨嵌入化合物(GIC)制备技术处理天然石墨, 然后在其表面包覆一层软炭前驱体, 并在惰性气氛下热处理. 所得样品不但层间距保持了拉大的状态, 而且还在天然石墨内部预留了膨胀空间. 成功地找到了在保持天然石墨粒度和碳六角平面直径不显著改变情况下, 提高石墨层间距, 预留膨胀空间的石墨改性方法. 分析表明, 石墨嵌入化合物表面含有的大量含氧官能团, 在软炭前驱体包覆石墨嵌入化合物的过程中, 含氧官能团与沥青之间的反应和石墨嵌入化合物分解产生气体的溢出阻碍了层间距和预留空间的恢复. 将这种材料用于锂离子电池负极材料, 石墨的可逆储锂容量变化不大, 但是倍率放电性能和循环性能得到明显改善. 这主要是因为加大层间距和预留膨胀空间, 拓宽了锂离子扩散通道, 降低了石墨嵌锂膨胀引起的包覆层破裂.     

石墨氧化过程的XRD/XPS研究

石墨用强氧化剂如硝酸、高氯酸、氯酸钾或高锰酸钾等处理后,在石墨层间形成一种没有化学计量的层间化合物,通常叫做氧化石墨,又称石墨酸犤1犦。氧化石墨的研究历史可追溯到1855年犤2犦,期间,有关氧化石墨的制备及表征的报导获得了广泛的重视。就目前的研究现状而言,普遍认为化学法制备的氧化石墨中存在羟基、环氧官能团和双键结构犤3犦,这一结果已经得到广泛的证实,如FTIR犤4犦结果表明氧化石墨中含有C-OH、-OH、C=O等基团,13CNMR犤5犦也检测到与醚或羟基相联的碳原子,并发现sp2杂化的碳原子,元素分析的结果表明犤6犦,氧化石墨中的C/…     

石墨－AlCl3的熔盐电解合成及电化学性能

自六十年代以来,随着石里扬人化合物(GIC)材料在超导体、催化剂、高能量密度电池和有机反应试剂中的出现，人们对石墨层间化合物制备^[1-3]、性质和结构^[4-7]进行了详细研究.     

镍锌铁氧体/膨胀石墨/聚苯胺复合物的电磁损耗性能

用化学共沉淀法和原位乳液聚合法分别制备了镍锌铁氧体(Ni_xZn_1-xFe₂O₄)、Ni_0.7Zn_0.3Fe₂O₄/膨胀石墨(NZF/EG)二元复合物及其聚苯胺(PANI)包覆的三元复合物(NZF/EG/PANI)。用现代测试技术表征了样品的组成、结构、形貌和电磁性能。结果表明,NZF粒子较好地嵌入到EG的层间,PANI对NZF/EG的包覆效果良好;三元复合物的磁性能随磁性组分含量的减小而减弱,而电导率与EG和PANI的导电性及其相对含量相关联;复合物的电磁损耗性能优良,其中三元复合物优于二元复合物。含PANI 70wt%的NZF/EG/PANI三元复合物,制样厚度分别为1.5、2.0和2.5 mm时,其反射损耗峰值(有效带宽)分别为-19.99 dB(5.82 GHz),-20.33 dB (4.08 GHz)和-25.28 dB(3.67 GHz),具有优良的电磁波吸收效果。     

聚氧化乙烯/蒙脱土纳米嵌入化合物的制备与结构表征

利用溶液法和熔融法制备聚氧化乙烯(PEO)/蒙脱土纳米嵌入化合物,用XRD、IR和DSC等测试手段对嵌入化合物进行了表征.嵌入的PEO分子同蒙脱土晶层中的Na⁺生成PEO-Na⁺络合物,嵌入化合物具有一定的耐溶剂萃取性,PEO分子以单层螺旋构象排列于蒙脱土的晶层中.PEO分子在蒙脱土层间运动受到限制,致使嵌入化合物的结晶熔融峰减弱.     

Electronic Effect of Carbon Support on Pt Catalyst Supported on Graphite Intercalation Compound

Graphite intercalation compounds(GIC) were tested as an experimental model for studying the electronic effect of carbon support on the catalytic activity and poisoning tolerance of Pt catalyst for direct methanol fuel cells. The GIC samples with different intercalation degrees were prepared by electrolyzing graphite flake in H2SO4 for varying the periods of time. The GIC-supported Pt catalyst was deposited electrochemically. The catalytic activity and poisoning tolerance of the GIC-supported Pt catalysts were evaluated. It was found that GIC with sulfate anion as intercalate was able to catalyze methanol electrooxidation, which could be related to the positive charges generated on the graphite layer upon intercalation. As intercalation degree increased, the catalytic activity of the GIC-supported Pt catalyst decreased while the poisoning tolerance improved. This suggests that electron donation from support to catalyst had great effect on both catalytic activity and poisoning tolerance of Pt catalyst. And intercalation can be adopted as another important way to make modification on carboneous catalyst support.     

高岭石/聚丙烯酰胺插层复合物的制备与表征

The kaolinite-polyacrylamide intercalation compound was prepared first by the displacement reaction of the kaolinite-formamide intercalation precursor with 30% acrylamide ethanol solution, and then the polymerization under 140℃ for 15h with the catalysis of dibenzoyl peroxide. The XRD analyses showed that the basal spacings of kaolinite-acrylamide intercalation compound and kaolinite-polyacrylamide compound were 1.135nm and 1.144nm respectively. The kaolinite-polyacrylamide compound was able to resist to 30-min washing with water, but the kaolinite-acrylamide compound was unstable during washing. FT-IR proved that the hydrogen bonds were formed between kaolinite Si-O group and polyacrylamide NH group and between kaolinite inner surface hydroxyl and polyacrylamide C=O group, and that parts of NH group keyed into the kaolinite ditrigonal hole. TG and DTG analysis proved that kaolinite-polyacrylamide was stable under 350℃. A net weight loss of 16.63% between 370℃～500℃ is due to the removal of intercalated polyacrylamide from the interlamellar space of kaolinite. These results clearly indicate that acrylamide has been intercalated into the layers of kaolinite and was polymerized in-situ.Based on the TG data, the formula of the kaolinite-polyacrylamide intercalation compound, Al₂Si₂O₅(OH)₄?CH₂CHCONH₂?_0.736, can be calculated.     

Thermal Decomposition of Ternary Sodium Graphite Intercalation Compounds

Graphite intercalation compounds (GICs) are often used to produce exfoliated or functionalised graphene related materials (GRMs) in a specific solvent. This study explores the formation of the Na-tetrahydrofuran (THF)-GIC and a new ternary system based on dimethylacetamide (DMAc). Detailed comparisons of in situ temperature dependent XRD with TGA-MS and Raman measurements reveal a series of dynamic transformations during heating. Surprisingly, the bulk of the intercalation compound is stable under ambient conditions, trapped between the graphene sheets. The heating process drives a reorganisation of the solvent and Na molecules, then an evaporation of the solvent; however, the solvent loss is arrested by restacking of the graphene layers, leading to trapped solvent bubbles. Eventually, the bubbles rupture, releasing the remaining solvent and creating expanded graphite. These trapped dopants may provide useful property enhancements, but also potentially confound measurements of grafting efficiency in liquid-phase covalent functionalization experiments on 2D materials.     

Fe/膨胀石墨插层复合物的简易制备与电磁特性研究

以膨胀石墨和硫酸亚铁为前驱物,采用一步还原法得到Fe/膨胀石墨(Fe/EG)插层复合物.并用SEM、XRD、网络矢量分析仪等测试仪器分别研究了Fe含量(wFe)对Fe/EG插层复合物的形貌、结构、微波电磁和吸波性能的影响.结果表明:改变插层剂Fe的含量能有效地调控Fe/EG插层复合物的微波电磁与吸收特性.随wFe在27.5wt%～71.5wt%范围内增大,Fe/EG插层复合物的介电常数在wFe=27.5wt%时达到最大值,磁导率呈现多重共振现象,微波吸收性能逐渐增强.这种优异的微波吸收特性归功于Fe/EG插层复合物增强的电磁匹配和磁共振损耗.     

Conditions for the Formation of a New Type of Graphite Intercalation Compounds with FeCl3 in Chloroform

A new type of structure of ferric chloride–graphite intercalation compounds (FeCl₃-GICs) was formed in the chloroform solutions of FeCl₃ with Cl₂ gas. The spacing between adjacent carbon layers containing the intercalate layer, (d₁-value) in the new type compounds was 1.18 nm, which is larger than the value of 0.94 nm typical for the compounds synthesized by other methods. In the beginning of the reaction, the structure of GICs formed was the same as that obtained by vapor method, but after several days of reaction the new type GICs (called type II here) appeared. This structural change was found to correspond to the change of the equilibrium state of a iron-chlorine complex in the chloroform solution by irradiation of light, which was detected by the UV-Vis absorption spectrum of the reaction solution.