模板技术制备有序大孔含硅聚酰亚胺薄膜

Macroporous Silicon-containing Polyimide Films Obtained via Colloidal Crystal Template

以二氧化硅胶体晶体为模板 ,将由含硅的芳香二酐单体与芳香二胺单体在N ,N 二甲基乙酰胺溶液中进行共聚得到的聚酰胺酸填入模板的空隙 ,经热环化 ,得到了二氧化硅 /含硅聚酰亚胺复合物 ,再用氢氟酸除去二氧化硅模板 ,制备出了有序大孔含硅聚酰亚胺薄膜 ,通过扫描电子显微镜和紫外 -可见光分光光度计对样品进行了表征 .研究表明 ,所制备的含硅聚酰亚胺多孔薄膜 ,孔大小均匀、无收缩 ,在空间排布高度有序 ,其有序结构与模板中二氧化硅微球自组装方式完全相同 ,并且大孔之间由小孔互相连通 .由于大孔的周期性排列 ,制备的薄膜表现出较好的光学特性 .含硅聚酰亚胺兼具聚酰亚胺和有机硅树脂的优良性能 ,使制备的有序大孔薄膜在光电器件、催化、吸附。

The preparation of macroporous silicon-containing polyimide films with regular voids and the characterization of their diffractive optical properties are reported in this paper. These materials were synthesized using a colloidal crystal template of silica microspheres. The air between the spheres was replaced by the poly(amic acid) that had been synthesized by copolymerizing monomer bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride with 4,4'-diaminodiphenyl ether in N, N-dimethylacetamide, the poly(amic acid) was subsequently cyclized, and the template was removed by treatment with hydrofluoric acid. Scanning electron microscopy (SEM) of these molded samples indicated highly uniform cavities ordered in hexagonal lattices, representing a negative replica of the original colloidal crystal. These large cavities are not isolated, but interconnected by a network of monodisperse smaller pores. These films exhibit striking optical proper-ties due to the periodic arrangement of air spheres in the silicon-containing polyimide. Because silicon-containing polymides have the good comprehensive properties of both polyimides and organosilicone resin, the macroporous material may have a wide range of applications as photoelectric device, catalytic surfaces and supports, separation and adsorbent media, biomaterials, etc.