Nanostructured silica-type hybrids from poly(styrene-b-ethylene oxide-b-caprolactone) copolymers

By employing a triblock copolymer, poly(styrene-b-ethylene oxide-b-caprolactone) copolymer, as a structure-directing agent, a series of silica-type hybrid materials were prepared via a sol-gel method of (3-glycidyloxypropyl) trimethoxy silane and aluminum sec-butoxide. Small angle X-ray scattering and transmission electron microscopy analyses demonstrated that ordered nanostructures, from lamellar to 2-dimensional hexagonal columnar with a disordered intermediate morphology, were exhibited as a function of the amount of loaded silica nanoparticles. Among the observed morphologies, the silica particles in the lamellar sample were localized at the PS/PEO interface, which could be elucidated by the dominant translational entropy of small silica particles.