高能离子注入聚酰亚胺薄膜表面结构研究

Study on the surface structure of polyimide films injected with high energy ion

应用透射电子显微镜研究了聚酰亚胺薄膜在无外加氮源、氢源参与的条件下,分别经过1.0,2.0,2.5MeV的He^+注入改性后表面的微观结构变化,通过选区电子衍射和高分辨等手段分析,首次发现在注入He^+后薄膜表层发生了不同程度的晶化,生成了类金刚石晶体和CN_x微晶。经一定能量He^+轰击后的聚酰亚胺薄膜的硬度、耐磨性及抗环境能力得到了提高。

The variations in surface microstructure of polyimide films were observed under transmission electron micro- scope after the film specimens was injected with the high energy He+ ions of 1.0 MeV ,2.0 Mev and 2.5 MeV, respectively, in the absence of involvement of external nitrogen source and hydrogen source. Through the analyses of micro - area electron diffraction and high - resolution electron microscopy, the phenomenon was discovered for the first time that crystallization at different level occurred in the surface layer of the polyimide films after injecting He+ ions. These observation results demonstrated the formation of diamond - like crystalline and CNx microcrys-talline. The surface hardness, wear resistance and environmental resistance of the polyimide films were improved in case the film specimens were subjected to the bombardment of He+ ion beam with a given energy.