Triblock copolymer-assisted synthesis of a hybrid mesoporous ethenylene–silica with 2D hexagonal structure and large pores

Abstract

Highly ordered hybrid mesoporous ethenylene–silica is successfully synthesized from bis(triethoxysilyl)ethylene under acidic conditions using triblock copolymer P123 as a structure-directing agent. The mesoporous material is confirmed to exhibit a two-dimensional, hexagonal structure based on analyses by powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The material is also shown to have a uniform pore size distribution with a mean diameter of 6.3 nm, with a BET surface area of 705 m² g⁻¹ and pore volume of 0.84 mL g⁻¹. The incorporation of ethenylene groups within the silicate framework is confirmed by solid-state nuclear magnetic resonance (NMR) measurements, and the formation of an organic–inorganic network composed of the O_1.5Si–CHCH–SiO_1.5 unit is strongly suggested by ¹³C and ²⁹Si NMR analyses. Quantitative analysis of the available ethenylene content by liquid-phase bromination followed by iodometric titration indicates that approximately 20% of the constituent ethenylene is exposed at the surface and available for chemical reaction.