1999-04-07
11:15 at NW B81

New building blocks to develop sol-gel materials: what can we measure, what can we model

Stelian Grigoras

Dow Corning ETH Zurich

The seminar will present a new route to produce sol-gel materials, starting with tetra-alkoxy cyclic tetrasiloxane. Using this compound as starting material, the structure of the product resulting from the acid catalyzed hydrolysis and condensation reaction is more uniform than the original route using alkyl trialkoxy silanes. NMR data allow to derive an average structure of the product, but the composition remains complex.

>From modeling point of view, possible structures resulting from the connection of the isomers of the cyclic tetrasiloxane were studied atomistically, to evaluate if different structures would have different properties, as a tool to target the separation, or synthetic effort towards materials with the suitable features. The mesoscopic approach (Palmyra) was then used to evaluate the elastic and thermal properties of cured materials.