Journal of the American Chemical Society, 130 (51), 17284, 2 Dec 2008
Understanding the nucleation and growth phenomena in solution is of fundamental and practical significance for the synthesis of various materials including zeolites. In this context, the synthesis of all-silica zeolite with MFI-type framework (referred to as MFI) has been studied extensively as a model system. Of fundamental importance is the role of nanoparticles (ca. 5 nm) present in the precursor sol in nucleation and crystallization Recently we proposed a mechanism in which the nanoparticles evolve towards the zeolite crystal structure, which can then contribute to crystal growth by aggregation.1, 2 However, information regarding the structure of the evolving nanoparticles, nuclei and early aggregates is limited since they are vaninshingly small components of the sols at the early stages of growth and due to the challenges of sample preparation and characterization.
1. Davis, T. M.; Drews, T. O.; Ramanan, H.; He, C.; Dong, J.;
Schnablegger, H.; Katsoulakis, M. A.; Kokkoli, E.; McCormick, A. V.;
Penn, R. L.; Tsapatsis, M., Nat. Mater. 2006,
2. Kumar, S.; Davis, T. M.; Ramanan, H.; Penn, R. L.; Tsapatsis, M., J. Phys. Chem. B 2007, 111, 3398-3403.
Financial support was provided by the NSF (NIRT-CMMI-0707610, -CBET-0522518 and the MRSEC Program: DMR-0212302). Characterization was carried out at the Characterization Facility, University of Minnesota, which receives support from NSF through the NNIN. ZW received support from China Scholorship Council (2007) for his stay at the University of Minnesota.