Structural Evolution of Silsesquioxane-based Organic/Inorganic Nanocomposite Networks

Richard Laine

E. KLWWCZ C. L. Soles and R. M Laine (2001)

in Organic/Inorganic Hybrid Materials–2000, MRS Symp. Ser., 628:CC4.2.1-6, R.M. Laine, C. Sanchez, and C.J. Brinker, eds. Mater. Res. Soc..

The basic tetrahedra of silica are readily assembled into eight cornered cages known as cubic silsesquioxanes ([RSiO1.5]8). Silsesquioxane cubes represent one of the smallest possible units of ceramic silica. The corners of these nanometer-sized ceramic cubes are readily functionalized with reactive groups and incorporated into organic polymers. In this work, we characterize the structures that result from varying the length of the flexible organic segments used to connect the cubes in a series of hybrid network materials. For very short organic segments, steric hindrances inhibit high degrees of network conversion and the resulting network is very inhomogeneous. As the length of the flexible organic segment increases, the added degrees of freedom allow a more ‘ordered’ glassy material to evolve. If the length of the organic segment becomes very long in comparison to the size of the cube, a disordered polymer-like network is obtained.

nanocomposites, silsesquioxanes