Abstract: By using different zeolites(Nonasil, MCM-22 or MCM-49) as the crystal seeds, the synthesis of Nonasil(HMI) porosil was studied under hydrothermal conditions in the presence of hexamethyleneimine(HMI) as the organic template. Various synthesis parameters, including the type of crystal seeds, silica source, temperatures and the concentrations of Na⁺, are investigated for the synthesis of nonasil(HMI). It was found that the addition of crystal seeds could considerably shorten the time of crystallization in the presence of appropriate amount of Na⁺ and that different kinds of crystal seeds could accelerate the crystal growth with different degrees. Particularlly, nonasil(HMI) with a high crystallinity level can be obtained with heterogeneous crystal seeds(i.e. MCM-22, MCM-49).

Key words: Nonasil, Crystal seed, Hexamethyleneimine(HMI), MCM-22, MCM-49