基于气溶胶微空间的超长SiC纳米线生长及其连续纤维纺丝

连续SiC陶瓷纤维是高强度SiC陶瓷基复合材料不可缺少的增强体，在多个高技术领域具有广泛的应用前景。近几年，关于连续碳纳米管纤维纺丝的研究方兴未艾，这种由碳纳米管自下而上组装成宏观纤维材料的方法为新型连续SiC纤维的制备提供了新的研究思路。申请人拟在前期SiC纳米线研究的工作基础之上，研究碳气溶胶微空间超长单晶SiC纳米线的持续生长，并将生成的SiC纳米线气溶胶经直接纺丝获得连续SiC纳米线纤维。研究将澄清气溶胶微空间SiC纳米线的生长机理，确定SiC纳米线生长的关键制备技术和工艺参数。研究牵引、加捻和浸润等后处理工艺对纤维力学与物理性能的影响，并探讨通过液相聚碳硅烷浸渍工艺制备连续SiC纳米线陶瓷纤维。研究将重点解决气溶胶微空间SiC纳米线的持续稳定生长及SiC纳米线纤维的直接纺丝两个关键问题。这种新型SiC纳米线纤维的纺丝可为今后SiC纤维的研究与开发提供材料设计思想和关键制备技术。

The continuous SiC fibers which are used as important reinforcements for silicon carbide matrix composite have many promising applications in some high-tech fields. Recently, the spinning of the continuous carbon nanotube fibers is becoming a rapidly emerging field of material research. This spinning method accomplished by integrating bottom-up carbon nanotube self-assembly provides a new way for the fabrication of the new continuous SiC fibers. Based on our previous research work on SiC nanowires, the continuous growth of the ultralong single-crystalline SiC nanowires in the micro space of the carbon aerosol will be studied, and the continuous SiC nanowire fibers will also be spun directly from the as-synthesized SiC nanowire aerosol. The growth mechanism of SiC nanowires in the micro space of the aerosol will be clarified. The key technology and process control parameters will be confirmed. The effects of the post-processings on the mechanical and physical properties of the fibers will be investigated. SiC nanowire ceramic fibers will also be fabricated via polycarbosilane infiltration and pyrolysis technique. Two key problems, the continuous fabrication of SiC nanowires and the direct spinning of the continuous SiC nanowire fibers, will be resolved. The new spinning technique for SiC nanowire fibers will provide a new strategy toward materials design and fabrication for the research and development of the continous SiC fibers.