Macroporous materials by self-assembly of linear oligo(phenylsilsesquioxanes).

Materials with macroporous architecture were prepared in a template-free system using linear oligo(phenylsilsesquioxanes) (Ph-LPSQ), obtained in a two-step, one-pot, acid/base sol-gel method. The spontaneous self-assembly of silsesquioxane chains is governed by π-π interactions between side substituents and facilitated by the backbone rigidity of the polymer. The porous structure of the material can be changed on adjusting the processing conditions (concentration of Ph-LPSQ solution, the ratio solvent/nonsolvent and rate of stirring during precipitation). Ph-LPSQ oligomers can be also used for modification of silica particles and preparation of interesting macro-mesoporous materials of narrow pore size. Morphology and properties of the polymer and self-assembled particles were characterized by nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopies, wide angle X-ray scattering (WAXS), scanning electron microscopy SEM, mercury intrusion porosimetry, fluorescence spectroscopy and dynamic light scattering