Sol-gel process was utilized to produce organic/inorganic composite in this research, and the effect of mixing time¡]of polymer¡¦s and silica¡¦s precursor¡^ and coupling agent were investigated. To get low к materials was also the important objective. TMA, TGA, SEM, FT-IR, and RF impedance were used to investigate thermal properties, chemical bonding, morphology, and dielectric constant, respectively. The experiments showed that mixing time influence little to thermal stability but a lot to morphology and к. When mixing time was nearer to reaction time, the particle of silica was larger and the surface was flatter. The materials with coupling agent didn¡¦t show the same tendency as one without coupling agent. Regardless of coupling agent, it got larger к when mixing time was nearer to reaction time. Comparing with pure polymer, the modified materials got lower к. The lowest к got in this research was 2.36 which was lower than other materials.

Current membrane technology, based on polymeric materials, is subject to a limiting tradeoff between productivity (permeability) and efficiency (selectivity). Other materials with better gas separation performance exist, such as zeolites and carbon molecular sieves, but the physical characteristics of these materials inhibit industrial scale membrane preparation. This research focuses on the application of hybrid membrane technology, which has shown the ability to combine the advantageous properties of these materials, to a system comprised of carbon molecular sieves dispersed in the upper bound polymer 6FDA-6FpDA. Hybrid membranes require effective mass transfer across the interface between the two phases. This work shows the sensitivity of the component materials to processing conditions and the importance of consistency in gas separation membrane production. In particular, milling the sieves to reduce the size and using chemical linkage agents to bond to the polymer have potential to alter the separation performance of the respective materials. Analysis of multiple factors in this work provides important information regarding the source of unexpected properties in the hybrid membranes. Hybrid membrane testing in this work shows a need for active control of particle agglomerates within the dope prior to casting for effective membrane production. Continual sonication during the preparation of the casting dope was able to prevent the excessive agglomerates present in earlier trials. Further reduction of stresses generated during the casting process was also necessary to produce membranes with enhanced selectivity. Annealing the hybrid films above the polymer Tg appears to repair the interfacial morphology and produce effective membranes. The application of this process to enhance the gas separation performance of 6FDA-6FpDA represents the first known report of successful selectivity improvement in an upper bound polymer using the hybrid membrane approach.