炭化条件对炭纤维纳米微孔分形维数的影响

Influence of Carbonification Condition on Carbon Fiber Nanometer Micropore Fractal Dimension

应用X射线小角散射方法研究了炭纤维纳米微孔内表面特征的分形维数D.结果表明,不同炭化温度下得到的炭纤维,其微孔尺寸在1 60～4 13nm.随着炭化温度的升高(由900℃升至2400℃),D值增大(由2 09增加到2 59).当增大炭化牵伸率时,微孔分形维数也有所增加.从具有不同分形维数炭纤维力学强度的测试中发现,分形维数较低的试样,具有较高的拉伸强度和压缩强度.

By means of small angle X-ray scattering, the fractal dimension D for carbonfiber nanometer micropore inner surface is studied. The results show that the size of the carbon-fibers obtained at different carbonification temperatures varies from 1.6 nm to 4.13 nm. And as the carbonification temperature goes up from (900 ℃) to 2 400 ℃, the value of D also goes up from 2.09 to 2.59. When the carbonification draft ratio is (enlarged), the micropore fractal dimension will increase somewhat. By determining the mechanical intensity of the carbon-fibers which have different fractal dimension, it was found that those samples which have lower fractal dimension possess larger stretch intensity and condensation intensity.