O. Regev et al., APPLICATION OF THE INDIRECT FOURIER-TRANSFORM METHOD TO A STUDY OF ZEOLITE NUCLEATION, Journal de physique. IV, 3(C8), 1993, pp. 397-400
The nucleation events of synthesis reactions of ZSM5 and Na-A zeolites
were studied, with particular emphasis on the role of organic templat
e, TPA+ (tetrapropylammonium), in the ZSM5 synthesis. Qualitative eval
uation of the structural units was obtained by Small-Angle X-ray Scatt
ering (SAXS) measurements which were analyzed using an indirect Fourie
r transform method. In the presence of organic cation TPA+ in the ZSM5
synthesis we found globular structural units, 5 nm in diameter, which
aggregate to elongated bodies 44 nm long. These results suggest that
the zeolite ZSM5 building blocks are globular structural units, 5 nm i
n diameter, containing silica, alumina, organic cation and water, whic
h fuse together to produce elongated aggregates that may compose the f
inal unit cell. We found that the Na-A zeolite follows nucleation via
1 nm globular particles, which suggests that the existence of globular
structural units in the nucleation of zeolites is a general phenomeno
n.