High Strengthening of Carbon Fiber by Imposition ofa High Magnetic Field

结果表明，在石墨化过程中，PAN基碳纤维在强磁场作用下，其抗拉强度比无磁场作用下提高了30%。在碳化过程中，强磁场处理的碳纤维的抗拉强度比无磁场处理的碳纤维的抗拉强度高。另外，在稳定化过程中，磁场对低张力处理的碳纤维的影响大于高张力处理的碳纤维，研究发现，煤沥青热处理时，在磁场作用下，出现中间相小球并聚，其尺寸随磁场强度的增大而增大。进一步延长热处理时间可使中间相小球转变为板状碳。利用红外光谱研究了其形貌变化。已经发现，通过施加高磁场促进脱氢反应。此外，强磁场促进脱氢反应的原因可以用磁场中的自由基对理论来解释。

It has been found that when PAN-based carbon fibers are processed under a high magnetic field in the graphitization process, their tensile strength is increased in 30% in comparison with that processed under no magnetic field. It has also been investigated that in the carbonization process, the tensile strength of carbon fibers processed under a high magnetic field is higher than that under no magnetic field. Furthermore, in the stabilization process, the effect of a magnetic field on carbon fibers processed in a low tension is larger than that processed in a high tension.It has been found that when a coal tar pitch is heat-treated, appearing mesophase spherules coalesce under the imposition of a magnetic field and their sizes are increased with increase of a magnetic field intensity. The further long heat-treating time changs mesophase spherules to tabular carbons. The morphology change was investigated by use of IR spectra. It has been found that a dehydrogenation reaction is promoted by imposition of a high magnetic field. Furthermore, the reason that the dehydrogenation reaction is promoted by the imposition of a high magnetic field can be explained on the basis ofa radical pair theory in a magnetic field.