Preparation and Characterization of Novel Mixed Periodic Mesoporous Organosilica Nanoparticles.

We report herein the preparation of mixed periodic mesoporous organosilica nanoparticles (E-Pn 75/25 and 90/10 PMO NPs) by sol-gel co-condensation of E-1,2-bis(triethoxysilyl)ethylene ((E)-BTSE or E) with previously synthesized disilylated tert-butyl 3,5-dialkoxybenzoates bearing either sulfide (precursor P1) or carbamate (precursor P2) functionalities in the linker. The syntheses were performed with cetyltrimethylammonium bromide (CTAB) as template in the presence of sodium hydroxide in water at 80 °C. The nanomaterials have been characterized by Transmission Electron Microscopy (TEM), nitrogen-sorption measurements (BET), Dynamic Light Scattering (DLS), zeta-potential, Thermogravimetric Analysis (TGA), FTIR, 13C CP MAS NMR and small angle X-ray diffraction (p-XRD). All the nanomaterials were obtained as mesoporous rodlike-shape nanoparticles. Remarkably, E-Pn 90/10 PMO NPs presented high specific surface areas ranging from 700 to 970 m2g-1, comparable or even higher than pure E PMO nanorods. Moreover, XRD analyses showed an organized porosity for E-P1 90/10 PMO NPs typical for a hexagonal 2D symmetry. The other materials showed a worm-like mesoporosity.