HIGH-RESOLUTION ELECTRON-MICROSCOPY STUDY ON THE GROWTH OF ZEOLITE-L NANOCLUSTERS

The synthesis of zeolite L nanoclusters that starts from a clear mixtu re and proceeds through the formation of an amorphous gel phase is fol lowed by high-resolution transmission electron microscopy (HRTEM). It is shown that by examining the solid products from partially crystalli zed samples, it is possible to deduce information concerning growth ev ents at the nanometer scale. HRTEM studies reveal a definite link betw een the gel microstructure and the zeolite L nanocluster morphology. M oreover, it is demonstrated that a cautious interpretation of HRTEM in formation does not justify the conclusion that growth takes place by a gglomeration of individual zeolite L nanocrystals but rather by propag ation of more isolated nucleation events through the gel network.