3. Results and discussion
3.1 Nucleation/crystal growth mechanism of ZSM-5
zeolites
The nucleation/crystal growth mechanism is significant for the
controllable synthesis of ZSM-5 zeolites. The characterization methods
with high sensitivity to the amorphous matrix and crystalline species
are necessary for the mechanism study [28]. FTIR spectroscopy is
often employed to observe the short-range order structures of crystals,
and IR vibrations of the structural units of zeolites are intense in the
nucleation process [29]. XRD analysis is usually used to study the
long-range order structures of crystals, which is beneficial to studying
the growth process of zeolites [30]. Fig. 2 displays the FTIR
spectra of solid aliquots drawn off the reaction mixture at t = 0.5 h
(after RPB premix) and t = 1.5-8.5 h (under dynamic crystallization at
130 ℃).