Self-assembled films of well-defined olystyrene-b-poly(acryloxypropyltriethoxysilane)-b-polystyrene triblock copolymers are prepared by solvent casting, as presented by Emmanuel Beyou and colleagues On page 4193. An ordered nanostructure of alternating PS and PAPTES lamellae is observed regardless of the copolymer composition. The average d-spacing is estimated from the electron micrographs to be 34.3 nm for the PS272PAPTES130PS268 sample. Cross-linking of the inner PAPTES block is performed through hydrolysiscondensation of the ethoxysilyl groups in acidic medium and the formed hybrid structure is confirmed from the residual weight loss after removing the organic polymer by calcination at 800°C under argon. As shown by the SEM image, the lamellar shape of the PS272PAPTES130PS268 sample is retained after calcination with a dspacing close to that of the corresponding hybrid film.