γ射线辐照后木荷粉自由基的ESR和XPS分析

利用电子自旋共振波谱（ESR）和X射线光电子能谱（XPS）技术分别测量γ射线辐照后木荷粉体的自由基波谱和X射线光电子能谱。分析木荷粉体在60Coγ射线辐照下自由基的变化规律、化学组成和结构变化。结果表明：木荷自由基的光谱分裂因子g=2．0033，自由基的强度随吸收剂量按指数规律，I=1-e40增加；经过200kGy剂量的辐照后木荷表面O／C原子比稍有增加，C—C、C—H和C-O键含量增加，C=O双键含量减少，-O—C=O含量增加为原来的2．5倍，说明木材表面生成了一些含氧官能团，或碳的氧化态增高。

ESR and XPS analysis of schima superba powder after y-rays irradiation

Electron spin resonance （ESR） and X-rays photoelectron spectroscopy （XPS） techniques were used to study the variation of the free radical, the chemical structure and components of the schima superba powder irradiated by 60Co γ-rays. The results show that the intensity of free radicals increases with the absorbed doses according to the exponential law of/= 1 - e-b-h,D when the spectral splitting factor of the free radicals （g） is 2.0033. The O/C atomic ra- tio in the schima superba powder surface increases slightly after 200 kGy dose irradiation. At the same time, the con- tents of the C--C, C-H and C-O increase, and the C=O content decreases. The content of the -O-C=O increases to 2.5 times of the original. These phenomena may indicate that some oxygen-containing functional groups occurred on the schima superba surface and the structure of organic carbon has been changed.