No abstract

No abstract

No abstract

A detailed atomic force microscopy study has been performed on the open-framework, microporous material silicalite. Emphasis has been placed on determining the effect of supersaturation on the crystal growth process. The relative rates of fundamental crystal growth processes can be substantially altered by tuning the supersaturation. In this manner, it is possible to, for instance, switch on and off surface nucleation while retaining terrace spreading. This offers a potential mechanism by which it might be possible to control important crystal aspects such as defect density and intergrowths.

Silicalite membranes have been prepared using a novel seeding method. By sonicating silicalite seed crystals in the presence of a stainless steel mesh followed by a controlled hydrothermal synthesis step it has been shown by AFM, SEM, and simple diffusion measurements that coherent membranes are produced. The sonication step anchors the nanometer-sized zeolite seeds to the porous stainless steel support and the subsequent hydrothermal growth produces a zeolite membrane grown on this seed layer.