title: Confined Polymerization in Highly Ordered Mesoporous Organosilicas.
abstract: Hybrid mesoporous organosilica exhibiting crystal-like order in the walls provided an ideal channel reaction vessel for the confined polymerization of acrylonitrile (PAN). The resulting high-molecular-mass PAN fills the channels at high yield and forms an ordered nanostructure of polymer nanobundles enclosed into the hybrid matrix. The in situ thermal transformation of PAN into rigid polyconjugated and, eventually, into condensed polyaromatic carbon nanofibers, retains the periodic architecture. Simultaneously, the matrix evolves showing the fusion of the p-phenylene rings and the cleavage of carbonsilicon bonds: this gives rise to graphitic-carbon/silica nanocomposites containing hyper-oxydrylated silica nanophases. Interestingly, the 3D hexagonal mesostructure survives in the carbonaceous material. The exploitation of porous materials of high capacity and a hybrid nature, for polymerization in the confined state, followed by high temperature treatments, allowed us to achieve unique and precisely fabricated nanostructures, thus paving the way for the construction of fine-tuned electronic and light-harvesting materials.
authors.affiliation: Department of Materials Science, University of Milano Bicocca, Via. R. Cozzi 55, 20125 Milan (Italy).
authors.forename: Angiolina
authors.initials: A
authors.lastname: Comotti
authors.affiliation: Department of Materials Science, University of Milano Bicocca, Via. R. Cozzi 55, 20125 Milan (Italy). silvia.bracco@unimib.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Bracco
authors.affiliation: Department of Materials Science, University of Milano Bicocca, Via. R. Cozzi 55, 20125 Milan (Italy).
authors.forename: Mario
authors.initials: M
authors.lastname: Beretta
authors.affiliation: Department of Materials Science, University of Milano Bicocca, Via. R. Cozzi 55, 20125 Milan (Italy).
authors.forename: Jacopo
authors.initials: J
authors.lastname: Perego
authors.affiliation: Center for Nanotechnology Innovation@ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy).
authors.forename: Mauro
authors.initials: M
authors.lastname: Gemmi
authors.affiliation: Department of Materials Science, University of Milano Bicocca, Via. R. Cozzi 55, 20125 Milan (Italy). piero.sozzani@mater.unimib.it.
authors.forename: Piero
authors.initials: P
authors.lastname: Sozzani
keywords: NMR spectroscopy; confined polymerization; ladder polymers; mesoporous organosilicas; nanostructures