Aerosol-synthesis of mesoporous organosilica nanoparticles with highly reactive, superacidic surfaces comprising sulfonic acid entities

Abstract

Combining high internal surface area with tailor-made surface properties is pivotal for granting advanced functional properties in many areas like heterogeneous catalysis, electrode materials, membranes, or also biomimetics. In this respect, organic-inorganic hybrid nanostructures and in particular mesoporous organosilica materials are ideal systems. Here, the preparation of mesoporous solids via a new sol–gel building block comprising sulfonic acid (R-SO3H) is described. The degree of organic modification is not only maximal (100%), it is also proven that the novel material exhibits superacid properties. Furthermore, an aerosol assisted method is applied for generating this material in the form of mesoporous, spherical nanoparticles with substantial colloidal stability. Highly acidic, high surface area materials, like prepared here, are promising candidates for numerous future applications like in heterogeneous catalysis or for proton conducting membranes. However, first experiments addressing the antibacterial effect of the sulfonic-acid, mesoporous organosilica materials are shown. It is demonstrated that the superacid character is required for exhibiting sufficient antifouling activity.