摘要
以含有喹啉不溶物的煤焦油沥青为原料,在410℃、不同反应时间下获得一系列中间相炭微球(MCMB)和小于0.5μm的碳质颗粒(SCP)。通过对中间相沥青的软化点、族组成和MCMB、SCP的形貌及MCMB断面结构的分析,认为非均相成核MCMB的形成和生长过程不同于均相成核的融并生长过程,而是SCP碳质颗粒的构筑过程,我们称之为"球形基本单元构筑"过程。在MCMB生长过程中,体系的黏度对SCP的形成和MCMB的生长起着重要的作用。非均相成核MCMB的内部结构不是三种模型结构("地球仪"型、"洋葱"型和"同心圆"型)中的任一种,而是炭层具有收缩点的复杂结构,并且球体的结构不具有"继承性",即随着反应时间的延长而不断发生变化和调整。MCMB内部分子在球体生长过程中的主要变化趋势是分子的不断缩合长大,而不是分子片层的平行趋向。
A series of mesocarbon microbeads (MCMB) and small carbonaceous particles (SCP) with size less than 0.5 mum were prepared from a coal tar pitch containing quinoline insolubles at 410degreesC by varying the holding time. By analyzing softening point and solubility of the as-received mesophase pitches, morphologies of the MCMB and SCP, and cross-section area of the MCMB, it was found that the development of the MCMB formed through heterogeneous nucleation did not follow the coalescence development as the homogeneous nucleation of MCMB but kept to the process of Building from Spherical Basic Units ( BSBU), in which spherical SCP were the basic units to build MCMB spheres. During this process, the viscosity of the system was the important factor that had great influence in the production of MCMB and SCP. The internal microtextures of MCMB were none of the three model structures of global type, onion type and concentric circles type, but a complex structure with the carbon layers converging at one or two points. With increased the holding time, the structures of MCMB did not inherit the previously formed structures, but the carbon layers changed and rearranged into new types. The main tendency of the carbon layer rearrangement in MCMB was not to make the carbon layers parallel but to make them become larger.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
2004年第4期281-288,共8页
New Carbon Materials
基金
国家自然科学基金(50172034)~~
