3MeV硅离子辐照聚苯乙烯引起的化学改性

Chemical modifications of polystyrene irradiated with 3MeV silicon ions

在室温下用 3MeV硅离子对聚苯乙烯薄膜进行了辐照注入 ,并对辐照后的样品进行了傅立叶转换红外反射光谱和紫外 /可见透射光谱的测量。测量结果显示 ,材料经 3× 10 13 ions/cm2 以上剂量辐照后 (即吸收剂量在约 4 5MGy以上时 )迅速降解 ,包括苯环在内的大部分特征官能团遭到破坏 ;与此同时 ,材料的光能隙随着剂量的增大逐渐减小 ,在辐照剂量达到 1× 10 14 ions/cm2 和 3× 10 14 ions/cm2 时 ,材料的光能隙分别由原来的 2 .7eV减小到 1.85eV和 1.2eV。

Polystyrene films were irradiated with 3MeV silicon ions ranging from 1×10 12ions/cm 2 to 3×10 14ions/cm 2 at room temperature. Fourier-transform infrared spectra, reflection spectra and ultraviolet/visible transmission spectra were measured to investigate the radiation induced chemical modifications of the material. It was found that the material underwent significant degradation at fluences higher than 3×10 13ions/cm 2, corresponding to an average energy deposition of about 45MGy. Most of the functional groups including the phenyl ring were destroyed at high fluence. Simultaneously the energy gap of the material decreased with increasing fluence. At fluences of 1×10 14ions/cm 2 and 3×10 14ions/cm 2, the energy gap reduced from about 2.7eV to 1.85eV and 1.2eV, respectively. It is concluded that the irradiated film is transformed gradually into hydrogenated amorphous carbon at high fluence.