纳米洋葱状富勒烯的研究进展及动向

评述了纳米洋葱状富勒烯的研究发展过程和动向，论述了该物质的各种制备方法及其工艺，并对各种制备工艺进行了分析和探讨性研究，在此基础上比较论述了每种方法的优缺点，展望了纳米洋葱状富勒烯基础研究，宏量制备和应用研究的发展趋向。     

水下放电制备内包金属洋葱状富勒烯的研究

以二茂铁和纳米Ni粒子为催化剂,在水下放电条件下,制备了内包金属洋葱状富勒烯(Onion-like Fullerenes:OLFs),利用高分辨透射电镜(HRTEM)和X射线衍射(XRD)对所得产物进行了表征.结果表明:二茂铁和纳米Ni粒子均可催化得到内包金属洋葱状富勒烯,内包Fe洋葱状富勒烯直径分布在5～50nm之间,内包Ni洋葱状富勒烯直径分布在10～35nm之间.     

纳米洋葱状富勒烯的研究现状及前景

通过述评纳米洋葱状富勒烯的结构、制备、生长机理、纯化、修饰及性能,指出:纳米洋葱状富勒烯具有独特的中空笼状及同心壳层结构,是富勒烯家族的一个重要成员,具有许多特殊性能,有望在能源材料、高性能、高温耐磨材料、超导材料和生物医用材料等领域得到广泛的应用.     

纳米金属微粒催化制备的洋葱状富勒烯的结构表征

采用金属Cu，Al做粒／石墨混合材料．用直流电弧放电方法制备了洋葱状富勒烯。对两种产物进行了XRD、SEM、HRTEM和Raman结构表征。结果表明：两种纳米金属微粒均可催化得到洋葱状富勒烯；所得产物中有单纯洋葱状富勒烯和内包纳米金属微粒洋葱状富勒烯，且石墨化程度都很高；纳米金属微粒尺寸大小不同决定洋葱状富勒烯的直径分布不均匀，从而造成其拉曼谱峰相对于石墨特征峰1582cm^-1发生了频移；用汽-液-固(VLS)生长模型描述了洋葱状富勒烯生长机理，解释了汽态碳原子通过在液态催化剂中扩散和析出，逐渐长大成形的现象。     

催化剂种类对纳米洋葱状富勒烯形成的影响

研究了相同电弧放电条件下,不同催化剂(Fe、Al)掺杂对洋葱状富勒烯形成的影响.用高分辨透射电子显微镜(HRTEM)和X-射线衍射(XRD)对产物进行了观察与表征.结果表明,Fe作催化剂形成的洋葱状富勒烯产量和质量都优于Al作催化剂的情况,Fe的催化活性较Al的高,是制备洋葱状富勒烯的一种更加有效的催化剂.     

电弧放电条件下内包金属洋葱状富勒烯生成机理的研究

采用电弧法制备内包纳米金属微粒的洋葱状富勒烯.通过XRD、SEM和HRTEM对样品进行结构表征和分析,讨论影响纳米洋葱状富勒烯生成的因素.结果表明:可以宏量地制备内包金属微粒的NSOFs,且晶化程度很高;优化工艺参数可获得合适的气相温度及温度梯度,有利于NSOFs的生成;建立了汽-液-固(VLS)生长模型以解释其形成机理.     

水中电弧法制备碳纳米葱

采用水介质中石墨电极直流电弧放电法大量制备了高质量碳纳米葱（又称洋葱状富勒稀），借助Raman光谱仪和高分辨透射电镜（HRTEM）对制备产物进行了结构表征和几何形貌分析。实验结果表明：水介质中石墨电弧法制备的碳纳米产物主要聚集在水面附近和容器底部，放电电流大小对水面附近和容器底部产物的组成和形貌有显著影响。在放电电流约为40A时，水面附近产物是直径为5nm～20nm的球形、洋葱状碳纳米葱。其产率约4．3mg／min。研究结果表明：采用水介质中石墨电弧法能大量制备高质量的碳纳米葱。     

水下电弧放电法制备洋葱状富勒烯

探索了纯石墨电极在水中放电制备洋葱状富勒烯（Onion-like fullerenes，OLFs）的过程和工艺。用高分辨透射电镜（High resolution transmission electron microscope。HRTEM）对生成的OLFs进行了形貌、结构的观察与表征。分析结果表明制得的OLFs具有各种不同形状的内核。石墨化程度很高，直径分布在5nm～40nm范围内。在一定范围内随着电流强度的增大OLFs的产量和产率都有不同程度的提高。     

Fe/洋葱状富勒烯的化学修饰及润滑性研究EI北大核心

采用化学气相沉积(CVD)法制备了内包金属Fe/洋葱状富勒烯,利用高分辨透射电镜(HETRM)、X-射线衍射(XRD)和傅立叶红外(FT-IR)等对产物的结构和形貌进行了表征;运用硬脂酸对Fe/洋葱状富勒进行化学修饰;着重讨论硬脂酸修饰后Fe/洋葱状富勒烯作为润滑油添加剂的分散性和稳定性。结果表明所制备的Fe/洋葱状富勒烯颗粒均匀,通过酯化反应Fe/洋葱状富勒烯能够被硬脂酸包覆,显著提高了Fe/洋葱状富勒烯在润滑油中的分散性和稳定性。在MRS-10A型四球摩擦试验机上考察了Fe/洋葱状富勒烯作为机油添加剂的润滑性能。     

微波等离子体法合成洋葱状富勒烯的研究

在微波等离子体条件下, 以乙炔炭黑/二茂铁为原料, 低温合成纳米洋葱状富勒烯(Nano-structured Onion-like Fullerenes: NSOFs). 采用HRTEM、Raman和XRD等分析方法对产物的形貌、尺寸、微观结构及其物相结构进行了表征. 结果表明, 以乙炔炭黑/二茂铁为原料可大量合成NSOFs, 其外观呈准球状或多面体状、实心、直径分布均匀, 最外碳层由闭合的、呈波浪状的石墨片构成.     

煤基纳米洋葱状富勒烯制备及其结构表征

在射频等离子体条件下以煤为原料制备纳米洋葱状富勒烯(Nano-structured Onion—like Fullerenes:NSOFs).高分辨透射电镜(HRTEM)和X射线衍射(XRD)表征结果表明:以煤为原料可大量制备NSOFs,纯度较高,无碳纳米管伴随生成,外观呈准球状或多面体状,内中空,直径分布较均匀,石墨化程度很高,为低成本合成纯净的NSOFs提供了一条新途径.     

Synthesis of fullerenes from carbon powder by using high power induction thermal plasma

Radio frequency (rf) inductively coupled thermal plasma (ICTP) was used to fabricate fullerenes (C₆₀,C₇₀, etc.) by direct evaporation of carbon powder injected into the plasma. Spectroscopic observation of the plasma was made for molecular band spectra of C₂ and atomic lines of C. The formation of fullerenes C₆₀ and C₇₀ as well as higher fullerenes were checked and recognized by high performance liquid chromatography (HPLC) and time-of-flight mass spectrometer (TFMS). The suitable conditions for the synthesis of fullerenes within the experimental conditions adopted were 10-kPa plasma pressure, with a considerably higher flow rate of approximately 150 l/min for mixed-gas condition of Ar, He and CO₂, with carbon powder of average diameter 20 μm. The results showed that the productivity of fullerenes has a relation to the intensity of C₂ molecular and C atomic spectra from the induction plasma. Mixing of Si with C particles has a kind of role in enhancing the synthesis rate of fullerenes C₆₀, as well as the higher order fullerenes.     

洋葱状富勒烯的研究进展

详细介绍和分析了洋葱状富勒烯(OLFS)的各种制备、纯化和改性方法,概述了其性能和应用的最新研究进展.OLFS特有的力、电、光、磁、吸附、催化等物理及化学性能,使其在工程、电子信息、能源、生物医学、化学化工、国防等领域有着广阔的应用前景.为此,应进一步围绕OLFS类新型纳米碳材料的制备、表面修饰、功能化、实际应用等各个环节的物理与化学问题进行探索,为该类功能材料的实际应用提供参考依据.     

洋葱状炭纳米粒子的无催化剂合成(英文)

描述了基于NaN3-C6Cl6混合物热解一步合成洋葱状碳纳米粒子的方法。应用EMS,XRD,Ramans研究了缓冲气体(Ar或空气)对炭产物的得率、形貌和结构的影响。产物包含洋葱炭、非晶碳和NaCl,通过简单的纯化处理即可完全除去副产物。洋葱状炭纳米粒子的形成由热解过程中压力迅速增加产生的震动波诱导苯基活性分子合并所制。     

The Role Of Defects In Graphitic Structures

The importance of defects in the formation of graphitic structures such as fullerenes, nanotubes, onion-like structures, helically coiled nanotubes and hypothetical periodic structures is analyzed. The structures mentioned above can also present defects which preserve their connectivity and topology. We have calculated the stability of Stone-Wales type defects in different shapes of graphitic structures finding that the energy required for these defects is not very high.     

重油残渣基新型碳功能材料的研究进展

综述了以重油残渣为原料,采用化学气相沉积法、共炭化法和微波等离子体法可控制备气相生长碳纤维、碳微球、内包铁洋葱状富勒烯、纳米碳管、内包金属碳微米颗粒及定向碳纳米薄膜等各种高附加值碳材料;采用等离子体氧化法、酸处理法、化学还原法等方法对气相生长碳纤维和碳微球进行表面修饰,在产物表面引入含氧官能团,解决了可溶性碳材料的制备问题;在碳微球表面引入Pt纳米颗粒,使重油残渣基新型碳材料在表面修饰和功能化后可望成为性能优异的吸附和催化材料.     

The Role Of Defects In Graphitic Structures

Abstract

The importance of defects in the formation of graphitic structures such as fullerenes, nanotubes, onion-like structures, helically coiled nanotubes and hypothetical periodic structures is analyzed. The structures mentioned above can also present defects which preserve their connectivity and topology. We have calculated the stability of Stone-Wales type defects in different shapes of graphitic structures finding that the energy required for these defects is not very high.     

ON THE MECHANISM OF CARBON CLUSTERS FORMATION UNDER LASER IRRADIATION. THE CASE OF DIAMOND GRAINS AND SOLID C60 FULLERENE

It is shown by FT-ICR (Fourier transform ion cyclotron resonance) mass spectrometry that carbon clusters considered to be the superior homologues of C₆₀ fullerene are formed by laser irradiation of both synthetic diamond grains or from pure C₆₀ fullerene crystals. The surfaces of the laser irradiated diamond or C₆₀ have been examined by Raman spectroscopy. In the case of diamond the Raman spectrum suggests the superficial formation of mixed carbon nanostructures consisting of disordered graphite, fullerenic nanostructures, onion-like carbon nanostructures and diamond-like carbon. Based on the Raman spectra of the surface and on data taken from the phase diagram of carbon, it is shown that the graphitization is needed in order to produce fullerenes from diamond under laser ablation conditions. In the case of C₆₀ fullerene, it is shown by Raman spectroscopy that the laser irradiation of the crystals causes initially their photopolymerization and after further irradiation their transformation into disordered graphite. Based on these results and on a literature survey on the formation of fullerenes from more than 15 completely different substrates, it is concluded that fullerenes are formed always when laser ablation leads to a graphitization of the laser-irradiated substrate. Some astrochemical implications of the conclusions have been discussed.