Formation mechanism of fullerenes

富勒烯的形成机理

基本信息

批准号：
11165222
负责人：
OSAWA Eiji
金额：
$ 12.03万
依托单位：
Toyohashi University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (A)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11165222/
关键词：
Mechanism of fullerene formation Natural fullerenes Coal Carbon black C60 TEM Shock wave peaceful use of explosives C_<60>生成機構 3次元螺旋ナノ粒子多層フラーレン煤電子線照射生成自由エネルギー天然カーボンナノチューブ天然カーボンナノ粒子 HPLC

项目摘要

Mechanism of fullerene formation is one of the most difficult problems in fullerene science but has been urgently needed in order to develop industrially favorable synthesis of C60, which is actually a critical obstacle to the emergence of applications of fullerene carbons. During the tenure of this grant, we clarified the mechanism and proposed two entirely new and promising methods of the preparation of C60.Our work is motivated by a novel coal sample arrived from Yunnan Province, China, that contains surprisingly high concentration of C60/C70 (an initial concentration immediately after excavation estimated to be 0.3%). We found three pieces of evidence that indicate that this particular coal has been exposed to shock wave. The strongest evidence is high abundance of the primary particles of soot with extremely small diameter (ca 10 nm in diameters). Noting the fact that the purest and the most readily available soot is commercial carbon black, we thereupon used carbon black in our s … More ubsequent study. Whereas carbon black did not contain measurable amounts of C60, we observed that the primary particles of carbon blacks are cleanly converted to onion-like multi-shell fullerenes upon irradiation with focused electron beam (a substitute of shock wave). Careful examination of this transformation in TEM revealed intervention of spiral particles as the intermediate. Furthermore, we also found that onion changes into spirals. We assumed that the spiral TEM images represent 3D spiroidal particles close in shape with onions. Chemical as well as numerical models were conceived and generated. These works eventually led us to construct a consistent mechanism of fullerene formation consisting of spiral growth of spiroids and the stabilization of spiroid particles into onions by reversible multiple bond cleavage/intershell valence isomerization reactions/multiple bond closure. Success of this mechanism to elucidate the origin of unique configuration of onions encouraged us to conceive a new method of C60 production that uses the production line of carbon black.Another new method of C60 production is simply to expose carbon to shock heating. If shock wave is generated by detonation of explosives and coal is carbon materials, the production of C60 may be carried out on the coal mine site. The method is cost effective, contributes to environmental problem by reducing the CO2 emission by burning coal as the fuel, and also promotes the use of explosives for peaceful purposes. There are already some examples previously reported in the literature that indicates that somewhat shock wave will generate fullerenes in stead of diamond under some conditions. For example, in a shock tube experiment, 300 ppm of C60 was formed when benzene was subjected to detonative shock. A few careful preliminary experiments will be needed to verify the present proposal. Less

富勒烯形成的机制是富勒烯科学中最困难的问题之一，但迫切需要为了发展C60的工业有利的综合，这实际上是富勒烯碳应用程序出现的关键障碍。在这笔赠款任期期间，我们将机制固定下来，并提出了两种全新的，有希望的准备方法。我们发现三个证据表明该特定煤炭已暴露于冲击波中。强有力的证据是直径极小的烟灰的主要颗粒（直径10 nm）。指出一个事实是，最纯净和最容易获得的烟灰是商业碳黑色，我们在我们的S中使用了碳黑色……更多的UB后续研究。尽管碳黑色不包含可测量量的C60，但我们观察到用聚焦的电子束（一种替代冲击波的替代品）在照射后将碳黑色的主要颗粒干净地转化为洋葱样的多壳富勒烯。仔细检查这种转化以TEM显示出螺旋颗粒作为中间体的间隔。此外，我们还发现洋葱变成了精神。我们假设螺旋TEM图像代表3D螺旋线颗粒与洋葱的形状紧密。构思和生成化学模型和数值模型。这些作品最终使我们通过可逆的多重键裂解/互壳异构化反应/多个键关闭来构建蛋白酶螺旋生长的一致机制以及螺旋体生长的一致性以及螺旋体颗粒稳定在洋葱中。这种机制的成功阐明了洋葱独特构型的起源，鼓励我们构想一种新的C60生产方法，该方法使用碳黑的生产线。另一个新的C60生产方法仅仅是为了使碳降低碳的加热。如果爆炸和煤炭是碳材料而产生的冲击波，则可以在煤矿地点进行C60的生产。该方法具有成本效益，可以通过燃烧煤作为燃料来减少二氧化碳排放，并促进炸药用于和平目的。先前在文献中已经报道了一些示例，这些例子表明，在某些条件下，冲击波会代替钻石的富勒烯。例如，在一次冲击管实验中，当苯受到爆炸性冲击时，形成了300 ppm的C60。需要进行一些仔细的初步实验来验证当前的建议。较少的