M. Chamoumi et al., CHARACTERIZATION OF OFFRETITE MODIFIED BY SILANATION WITH TETRAMETHOXYSILANE AND OCTAMETHYLCYCLOTETRASILOXANE, Zeolites, 14(4), 1994, pp. 282-289
Offretite has been modified (silanated) with octamethylcyclotetrasilox
ane (OMCTS) and tetramethylsiloxane (TMS) using an improved CVD method
. The parent and silanated offretites were characterized by scanning e
lectron microscopy, X-ray diffraction, i.r. spectroscopy, microporous
volume determination, and stepwise thermal desorption of ammonia. OMCT
S and TMS agents transform the more accessible silanol groups into [GR
APHICS] grafted groups, respectively. OMCTS was found to be a suitable
agent for the selective silanation of external acidic sites, leading
to unilayer grafting of the surface without reducing the internal site
number and the intracrystalline zeolite voids.