Harvesting and Manipulating Zeolite Nanocrystals
Recently, we have developed techniques to synthesize, isolate, harvest, and assemble silicalite nano-crystals into tightly bound aggregates having zeolitic domains interspersed by mesoporous areas. Crystals with well-defined zeolite structure, as small as 45 nm, have been synthesized then assembled into aggregate particles or planar films. This talk will touch briefly on two of these synthesis techniques, some characterizations of these aggregated nanocrystals, and some projections for future work in the area. Oriented films of zeolite crystals also can be prepared, using a concentrated precursor solution; an example of this process will be shown from prior work. Silicalite-1 microspheres, using a Dowex® ion-exchange resin as a macrotemplate, were prepared in the size range of ~.5-.65 mm, using hydrothermal synthesis times of 25 h, 35 h, and 45 h at 80 oC. Steaming time and temperature studies were also performed to determine the effect on the quality of the calcined product.
P. S. Sarangapani et al., "Harvesting and Manipulating Zeolite Nanocrystals", Advances in Science and Technology, Vol. 45, pp. 2096-2104, 2006