MORPHOLOGY AND CHARACTERIZATION OF POLYIMIDE/POLYSILSESQUIOXANE HYBRID FILMS WITH MESO/MACRO DOUBLE POROUS STRUCTURE.

Supercritical CO2 (ScCO2) can dissolve organic materials easily just by changing temperature and pressure. This property of ScCO2 can be applied to extract some ScCO2-philic organic molecules from matrix material. The ScCO2 was used to generate the meso/macro double porous structure of polyimide/polysilsesquioxane (PI/PSSQ) hybrid film. The morphology of the porous structure was measured by scanning electron microscope (SEM). Here, we demonstrate that the ScCO2 could penetrate into the hybrid thin film and take away the small molecules, which are the by-product (CO2) from the imidization reaction of the PI segment and the solvent remained in the PSSQ segment by sol-gel process. [ABSTRACT FROM AUTHOR]