D. Bersani et al., Structural changes induced by the catalyst in hybrid sol-gel films: a micro-Raman investigation, MATER LETT, 51(3), 2001, pp. 208-212
The effect of acid catalysts on the structure and properties of zirconia-ba
sed hybrid organic-inorganic thin films obtained by sol-gel, starting from
gamma -glycidoxypropyl-trimethoxysilane (GLYMO) and zirconium n-propoxide Z
r(C3H7)(4), is studied by means of micro-Raman spectroscopy. The kind of ne
twork formed during the polymerisation process depends on the catalyst: thi
s modifies the reactivity of the organic moiety of the GLYMO and a glass fo
rmer behaviour is obtained only when the epoxy ring of the GLYMO is cleaved
. Unopened epoxy rings, on the other hand, may protect the guest luminescen
t molecules. like the azo-dyes, to acid attacks. Nitric and acetic acids ar
e reported as examples. (C) 2001 Elsevier Science B.V. All rights reserved.