Topological Morphology of Methylsilsesquioxane Derivatives

A change in the morphological topology of particles of methylsilsesquioxane derivatives is observed with a change in the silicone monomer formulation. The particles change from a spherical shape to a hollow hemispherical shape with an increase in the content of silica-forming monomers in methylsilsesquioxane-forming monomers, whereas the spherical shape does not change with the addition of dimethyl silicone-forming monomers to methylsilsesquioxane-forming monomers. The intermediate shape is a sphere surrounded by a wrinkly surface, like a soccer ball, and the particle finally becomes a hollow hemisphere. These phenomena were examined by FT-IR, 29Si CP/MAS NMR (solid-state), and XPS spectra from the perspective of internal steric stress due to tetra- or trifunctional units in the particle core.