Polymer/silica nanocomposite micro-objects as a key point for silica-to-polymer shape replication

Abstract

Nanocomposite micro-objects of mesoporous silica with polymers have been obtained by inclusion polymerization of vinyl monomers (styrene and methylmethacrylate) via a radical process. The intimacy between the silica scaffold and the grown polymer has been addressed by a multi-technique approach and the extended interface has been recognized. In particular, phase-modulated Lee–Goldburg 2D heterocorrelated NMR was exploited to study the heterogeneous interfaces and the micro-adhesion between the inorganic matrix and the organic phase. By the in-depth characterization, it was possible to achieve a model in which polymer nanofibrils interact with the walls of the nanochannels in the mesoporous silica, resulting in interdigitated nanophases. A material consisting of two distinct phases so intimately entangled can explain the success of a replication process in which the morphology of the original material is entirely transposed to a polymeric material that fully retains its shape. The obtained micrometric shapes as well as their nanometric structure were directly observed, respectively, by scanning and transmission electron microscopies.