Development of continuous preparation process of the coiled-carbon fiber by CVD process

1)采用23mm内径卧式间歇式反应器对乙炔进行金属催化剂活化热解制备微卷曲碳纤维。详细考察了制备条件，并对其生长机理进行了探讨。(1)研究发现，迄今为止报道的Fe和NIs粉末对碳卷的制备没有催化作用，但在限制条件下有一定的催化作用，并使线圈收率达到10-20%。(2)在过渡金属碳化物中，TiC粉只给了碳卷。在钛氧化物中，Ti203粉末和氧化钛板制成碳卷（卷收率：13-27%）。(3)研究了总碳和碳卷在Ni单晶晶面上的沉积行为。各晶面的催化活性如下：Ni(100) >(11) >(110)。Ni（100）的线圈收率是Ni（110）的3倍。推测碳纤维卷曲的驱动力是碳在催化剂各自晶面沉积的各向异性行为。2)采用间歇式或连续式制备装置（60 mm径× 1000 mm长）制备微卷曲碳纤维，并详细考察其生长条件。(1)碳盘管完全生长在气源入口上部。(2)随着反应时间的延长，卷材得率呈线性增加，得到的卷材长度为1 ~ 2mm。(3)随着反应时间的延长，硬质镀层的层厚逐渐增加，特别是反应10 min后。(4)镍粉是最有效的催化剂。(5)用砂纸研磨大体积线圈，得到线圈长度为1 ~ 5微米的粉末状线圈。线圈长度的分布取决于所用砂纸的粒度。3)已经完成了大型样品制备的小型装置（容量几百克/月）的设计，目前正在准备设备。

1) Micro-coiled carbon fibers were prepared by a metal catalyst activated pyrolysis of acetylene using a batch-type reactor (23 mm I.D,horizontal -type). The preparation conditions were examined in detail, and the growth mechanism was discussed.(1) It was found that Fe and NIs powders, those were reported so far to have no catalytic effects for the preparation of the carbon coils, have some catalytic effects under restricted conditions, and gave a coil yield of 10-20%.(2) Among transition metal carbides, TiC powder exclusively gave the carbon coils. Among titanium oxides, Ti203 powder and oxidized Ti plate gave the carbon coils (coil yield : 13-27%).(3) Deposition behaviors of total carbon and carbon coils on the crystal faces of a Ni single crystal were examined. The catalytic activity of respective crystal faces were as follows ; Ni(100) > (11) > (110). The coil yield for the Ni(100) was three time of that of the Ni(110). It was supposed that a driving force of coiling of the carbon fibers was this anisotropic behavior for the carbon deposition on the respective crystal faces of the catalysts.2) Micro-coiled carbon fibers were prepared using a intermittent or contimuous preparation apparatus (60 mm I.D.x1,000 mm long), and growth conditions were examined in details.(1) The carbon coils exclusively grew on the upper part of the source gas inlet.(2) The coil yield lineary increased with increasing reaction time, and the coils with 1-2 mm long were obtained.(3) The layr thickness of the hard deposits increased with increasing reaction time, especially after 10 min.(4) Ni powder was the most effective catalyst.(5) Powder-like coils having 1-5 micron in coil length were obtained by abrading bulk-coils using emery papers. The distribution of coil length depended on the grain size of the used emery papers.3) Designing of a mini plant (capacity : few hundred grams/month) for the praparation of large samples have been accomplished, and now in preparing the apparatus.