Abstract
In this study, we aimed at design of tri-block polymers comprising propylene oxide chain connecting two ends of triquaternary ammonium groups, and used them and molecules with different types of amphiphilic groups for the synthesis of hierarchical zeolites in order to observe their influences on zeolite structure, morphology, and porosity. In the synthesis of hierarchical silicalite-1 with MFI structure, we added compunds including hexadecyl-trimethyl-ammonium bromide, poly(propylene glycol) bis(2-aminopropyl ether), or 1,3,5-trimethylbenzene and found that the surfactant with cationic quaternary ammonium groups or long propylene oxide chain strongly influenced the structure, crystallinity, and morphology of hierarchical silicalite-1. On the other hand, in the synthesis of SSZ-13 with CHA structure, we added tri-block polymers designed with different amphiphilic groups to synthesize hierarchical SSZ-13 with N,N,N-trimethyl-1-adamantammonium hydroxide (TMAdaOH) as structure-directing agent. We observed that the tri-block surfactants with different amphiphilic group induced the formation of zeolitic materials with diverse mophology and affected the zeolite crystallinity. We noted that 1-adamantyl-N+(CH3)2-C4H8Br hydrophilic group that interacts strongly with zeolite framework interfered the CHA structure formation when it is confined by short propylene oxide chain, and that tri-block polymers with long propylene oxide chain created defects on the surface of zeolite particles. Besides, we adjusted the ratio of TMAdaOH and tri-block polymers to synthesize spherical SSZ-13 particles with irregular surface defects and some mesoporosity.