Effects of inorganic components on aggregate structure of the PI/SiO2 hybrid film

In this paper, polyimide/SiO₂ (PI/SiO₂) hybrid films were prepared via the Sol-Gel process and thermal imidization by the hydrolysis and condensation of triethoxysilane (TEOS), methyl-triethoxysilane (MTEOS) and dimethyldiethoxylsilane (DDS) served as inorganic precursor respectively. The coupling agent used in these hybrid films is 3-amionpropyltriethoxysilane (APrTEOS). The microstructure of hybrid films was characterized by scanning electron microscope (SEM) and atomic force Microscope (AFM) respectively. The result shows that in the PI/TEOS-SiO₂ hybrid film, the inorganic particles in nano size were isolated when the silica content was 5 wt%. While for the PI/MTEOS-SiO₂ hybrid system, there were a few holes in the organic matrix and the silica particles is in the shape of oval-like and the particles produced agglomerating with the increasing of inorganic component. The quantity of holes was increased on the surface of the PI/DDS-SiO₂ hybrid system films. The inorganic particles were in the shape of sphere and generated agglomeration. So DDS is often used with other inorganic precursor.