Porous materials are an attractive playground for the confinement of polymers and polymerization reactions to take place. We explored the use of porous hosts of various nature from synthetic to biological origin. This approach enables to achieve intriguing molecular architectures and morphologies. Within the family of natural hosts, we proposed for the first time the use of dipeptides as crystalline hosts for in situ polymerization: they provide ideal spaces for orienting polymer microstructure during its formation, mimicking enzymes. Exclusively 1,4-trans diene polymers and isotactic polycryloniltrile were synthesized as the output of the rigorous order of the crystalline structure. In the case of PAN the curing treatment results in a carbon nanofibrils which retain the crystal morphology. Moreover, prompted by the exceptional absorption properties of porous organic polymers with BET surface areas of 5500 m2/g, we realized the confined polymerization of acrylonitrile to yield bi-continuous phase materials with extended interfaces. The porous aromatic frameworks can be envisaged as a cradle for thermally activated chemical reactions of confined PAN. Solid state 2D NMR could describe the intimacy of the nanophases and polymer confinement. Optical absorption of the cured nanocomposites in the visible and near-infrared spectra could be tuned as a function of the thermal treatment and the energy gap falls in the range of semiconductor. Interestingly, through CH∙∙∙pi interactions, the molecular recognition of specific blocks of triblock copolymers and amphidynamic molecules by a host molecule promotes the formation of hierarchical periodic structures and surface inclusion compounds, respectively. The formation of the supramolecular architectures was followed by in situ synchrotron XRD while specific intermolecular interactions were highlighted by fast-1H MAS NMR and GIAO HF ab initio calculations.
Sozzani, P., Comotti, A., Bracco, S., Beretta, M. (2013). Microporous materials for in situ polymerization and selective inclusion of block copolymers to fabricate hierarchical supramolecular architectures. In Book of Abstracts - 3rd International Conference on Multifunctional, Hybrid and Nanomaterials.
Microporous materials for in situ polymerization and selective inclusion of block copolymers to fabricate hierarchical supramolecular architectures
SOZZANI, PIERO ERNESTO;COMOTTI, ANGIOLINA;BRACCO, SILVIA;BERETTA, MARIO
2013
Abstract
Porous materials are an attractive playground for the confinement of polymers and polymerization reactions to take place. We explored the use of porous hosts of various nature from synthetic to biological origin. This approach enables to achieve intriguing molecular architectures and morphologies. Within the family of natural hosts, we proposed for the first time the use of dipeptides as crystalline hosts for in situ polymerization: they provide ideal spaces for orienting polymer microstructure during its formation, mimicking enzymes. Exclusively 1,4-trans diene polymers and isotactic polycryloniltrile were synthesized as the output of the rigorous order of the crystalline structure. In the case of PAN the curing treatment results in a carbon nanofibrils which retain the crystal morphology. Moreover, prompted by the exceptional absorption properties of porous organic polymers with BET surface areas of 5500 m2/g, we realized the confined polymerization of acrylonitrile to yield bi-continuous phase materials with extended interfaces. The porous aromatic frameworks can be envisaged as a cradle for thermally activated chemical reactions of confined PAN. Solid state 2D NMR could describe the intimacy of the nanophases and polymer confinement. Optical absorption of the cured nanocomposites in the visible and near-infrared spectra could be tuned as a function of the thermal treatment and the energy gap falls in the range of semiconductor. Interestingly, through CH∙∙∙pi interactions, the molecular recognition of specific blocks of triblock copolymers and amphidynamic molecules by a host molecule promotes the formation of hierarchical periodic structures and surface inclusion compounds, respectively. The formation of the supramolecular architectures was followed by in situ synchrotron XRD while specific intermolecular interactions were highlighted by fast-1H MAS NMR and GIAO HF ab initio calculations.
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