介孔SiO_2薄膜孔结构的慢正电子技术表征

Pore structure determination of mesoporous SiO_2 thin films by slow positron annihilation spectroscopy

通过蒸发诱导自组装技术制备了具有不同有序结构的介孔SiO2薄膜,并采用同步辐射X射线反射率以及慢正电子束流技术对其进行表征.实验结果表明,随着旋涂速率的增加,介孔结构由三维立方向二维六角结构转变,同时平均孔隙率随转速增加而减小.利用各向同性无机孔收缩模型和Fourier变换红外光谱,探讨了薄膜结构和正电子湮没参数的内在联系.

Mesoporous silica thin films with different pore shapes were prepared by evaporation induced self-assembly method. The synchrotron radiation x-ray reflectivity and slow positron annihilation techniques were used to characterize the pore structures. The results indicated that with increase of the spin-coating speed,the pore structure transformed from 3-D cubic to 2-D hexagonal,the average porosity also decreased. The correlation of the film structures and positron annihilation parameters was songht for with FT-IR spectroscopy and isotropic inorganic pore contraction model.