Discrete spherical colloidal TPA-silicalite-1 with the gel composition 1.0TPAOH:3.0SiO2:100H2O:xPromoter (Promoter= H 2SO4, HCl, HNO3 and NH4OH, x=0-0.5) has been synthesized at 100°C. The spherical compounds modified as functions of acidic species and added promoter amount were fully investigated using PXRD, SEM, Light scattering, Zeta potential and 29Si solid NMR. The mean sizes of H2SO4 -induced TPA-silicalite-1 were ranged from 200 to 500nm and agreed with the results of the light scattering. The spherical morphology of the TPA-silicalite-1 was compared with a typical silicalite-1 with multiple twins and hillock. These facts suggest acidic promoter addition in TPA-silicalite enhanced the interaction of TPA+ and the silica source, leading the effect of nucleation and crystallization, and led the preferred orientation of crystal growth due to regulate the shape of TPA-silicalite-1.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry