One-Pot Syntheses of the First Series of Emulsion Based Hierarchical Hybrid Organic−Inorganic Open-Cell Monoliths Possessing Tunable Functionality (Organo−Si(HIPE) Series)

The elaboration of organo−silica-based hybrid monoliths exhibiting a hierarchical trimodal porous structure (micro-, meso-, and macroporosity) with tunable functionality have been synthesized for the first time via high internal phase emulsion (HIPE) process and lyotropic mesophases. Through one-pot synthesis, many organic functionalities that can act as network modifiers (methyl, dinitrophenylamino, benzyl, and mercaptopropyl) or co-network formers (pyrrol) have been anchored to the amorphous silica porous network. The resulting materials have been thoroughly characterized via a large set of techniques: SEM, TEM, SAXS, mercury porosimetry, nitrogen adsorption isotherms, FTIR, 29 Si MAS NMR, and XPS. These sol−gel-derived hierarchical open-cell functional hybrid monoliths exhibit macroscopic void spaces ranging from 5 μm up to 30 μm and their accessible micro-and mesoporosities reveal hexagonal organization for the dinitrophenylamino-, benzyl-, and pyrrol-based hybrids. The average condensation degree for these hybrid networks ranges between 86 and 90%, yielding shaped monoliths with both good integrity and sufficient mechanical properties to be usable as functional catalytic or chromatographic supports. Also, function accessibility has been demonstrated through heterogeneous nucleation of Pd metallic nanoparticles.