STUDIES ON THE CRYSTALLIZATION BEHAVIOR OF ZEOLITE SILICALITE-1 IN (TPA)(2)O-NA2O-SIO2-H2O SYSTEM .2.

Zeolite silicalite-1 with a high crystallinity was synthesized in the system of (TPA)(2)O-Na2O-SiO2-H2O at 60 degrees C by using fumed silic a-silica aerogel (I) or silica sol (II) as the silicon source, The cry stal size of products obtained is 0.2 mu m in (I) and 0.45 mu m in (II ) measured by SEM, and 0.02 mu m determined by the method of XRD peak broadness, In comparison with the properties of sample A prepared at 1 80 degrees C, the fine crystals B synthesized at 60 degrees C possess some characters which the nanometer particles have, The adsorption of n-hexane on sample B is abnormaly high, Investigated by XRD, FT-IR, Si -29 MAS NMR and TG/DTG/DTA, the temperatures for structural damage and for monoclinic/orthorhombic symmetry transformation of sample B are o bviously lower than that of sample A, The defects of Si-OH in sample B are much more than those in sample A.