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Tetrabutylphosphonium Cation as Template in the Kinetics of Crystallisation of ZSM‐5
Author(s) -
Lingappan N.,
Krishnasamy V.
Publication year - 1996
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170310303
Subject(s) - nucleation , crystallization , zeolite , chemistry , kinetics , zsm 5 , sodium aluminate , chemical engineering , silicate , template , molecule , morphology (biology) , sodium silicate , catalysis , crystallography , materials science , organic chemistry , aluminium , nanotechnology , physics , quantum mechanics , biology , engineering , genetics
Zeolite ZSM‐5 was synthesised using ethyl silicate ester 40 and sodium aluminate so as to get the gel mix with SiO 4 /Al 2 O 3 = 90 employing TBPCl and TPABr templates separately (for comparison) at temperatures 423 K, 448 K, and 473 K. Nucleation and crystallisation processes were kinetically analysed. Activation energies for nucelation and crystallisation and the geometric factors have been evaluated. Correlations were found between the kinetic characteristics and the habits of the crystals formed. The study of the composition and morphology of the intermediates, with the support of SEM pictures, reveal the different mechanisms operating in the templating action of TBPCl and TPABr molecules.