【作者】 王云鹏；

【导师】 邱介山；

【作者基本信息】 大连理工大学 ， 化学工艺， 2003， 硕士

【摘要】 本论文的工作主要围绕煤基纳米／微米碳材料的制备进行，内容包括直流电弧法水相煤基碳纳米管的制备及直流电弧法气相煤基炭微米球的制备两部分。产物的表征采用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线能谱(EDS)、以及红外光谱(FT-IR)；此外还使用可见发射光谱(OES)对放电过程电弧弧柱中的活性物种进行了原位诊断。结合实验现象和各种表征手段获得的信息对电弧法水相煤基碳纳米管和电弧法气相煤基炭微球的生长机理进行了初步讨论。 实验结果表明： (一) 以煤基碳棒为原料，采用直流电弧等离子放电方法可在水相环境中制备获得碳纳米管。与传统的气相放电技术方法相比，水相制备法所需设备简单、操作便捷、产品杂质少；与水相中制备的石墨基碳纳米管相比，水相法煤基碳纳米管的能耗小、成本低。煤基碳纳米管的生长经历了一个比较特殊的过程，其中煤棒在电弧作用下电离产生的芳香性碎片等活性物种可能直接参与了碳纳米管的生长，这与实验中使用的独特水相环境及炭化煤棒的结构有关。 (二) 直流电弧法气相煤基炭微米球与传统的中间相炭微球之形态、结构及生长机理截然不同；直流电弧放电中炭微米球在阳极表面近弧的位置沉积，呈单球状或以各种方式结合堆积，其形成与所用阳极基体的表面性质和放电时使用的缓冲气体的组成有关，实验证实在缓冲气体中加入乙炔对炭微球的生长有促进作用。更多还原

【Abstract】 This paper focuses on the preparation of coal-based carbon nanotubes (CNTs) and carbon microballs. The CNTs were prepared by DC arc discharge of coal-based rods in water, while the ball-like carbons were made by DC arc discharge of coal-based rods in different gases. The products were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM) , X-ray diffraction technique (XRD), X-ray energy dispersive spectroscopy (EDS) and IR spectroscopy, at the same time, the optical emission spectroscopy (OES) was adopted for in situ diagnosis of active species involved in the arcing process. On basis of the experimental results, the formation mechanism of coal-based CNTs as well as the formation mechanism of ball-like carbons are proposed and discussed in terms of the process parameters and coal properties.The results show that it is possible to produce CNTs with high quality and low cost by arc discharge of coal-based carob rods in water. The OES analysis revealed that in addition to C1 and C2, some other active species also get involved in the formation reactions in the arc plasma. It leads one to believe that the formation of CNTs in water medium may proceed via a scheme that is different from the conventional arc discharge in gaseous medium, in which some large active fragments released from coal-based carbon rods may play an important role in the growth process of CNTs.A novel ball-like carbon material with diameter in micrometer range was successfully prepared, for the first time, from coal-based carbon rods by dc arc discharge method. It has been found that the ball-like material mainly consists of carbon with a high degree of graphitization. These novel micro-sized carbons have a diverse morphology, such as chain-like or plate-like carbons. It is found that adding acetylene into the buffer gas in the arc system can help promote the formation of these ball-like carbons which also depends, to some degree, on the surface properties of the anode.更多还原