| 초록 |
A novel synthetic process for the multi-porous organic/inorganic hybrid films has been investigated using supercritical technology. Two reaction mechanisms for a double pore system were used in supercritical carbon dioxide(SCCO2). Micro pores were generated in the organic segment of hybrid films by condensation polymerization of polyimide(PI). PI precursors were synthesized by reaction of diisocyanates(MDI) and diphthalic anhydride(6FDA) and hybridized with inorganic materials, poly(methylsilsesquioxane)(PMSSQ). PI/PMSSQ precursors that were prepared by solution polymerization were cured in supercritical CO2 media. During the curing process, the micro/nano pores were generated inside of the PI/PSSQ hybrid films. PI precursors were imidized and, at the same time, generated CO2 as by-product. The supercritical CO2 makes it possible to take away CO2. It is empty spaces where CO2 existed that form micro-pores. In case of nanopores in the inorganic segment of hybrid films, they were made by sol-gel reaction of PMSSQ via supercritical drying. In addition, the size of micro pores in PI segment could be controlled in the range of from nano to micron size by changing the supercritical process condition. |
