A novel pH-responsive POSS-based nanoporous luminescent material derived from brominated distyrylpyridine and octavinylsilsesquioxane

Abstract

For the first time, a novel pH-responsive porous material based on POSS was easily prepared from the cubic octavinylsilsesquioxane (OVS) and brominated distyrylpyridine (Br-DSP) via the Heck coupling reaction. The resulting material possessed high porosity with Brunauer–Emmett–Teller specific surface area of 600 m² g⁻¹ and total pore volume of 0.58 cm³ g⁻¹. It also exhibited high CO₂ storage capability of 0.82 mmol g⁻¹ (3.62 wt%) at 298 K/760 Torr. The porous polymer was luminescent with the maximum emission at ca. 530 nm in the solid state, due to the incorporation of the conjugated structures of distyrylpyridine. Owing to the protonated nitrogen centers in the porous material, an excellent pH-responsive property was observed and a linear relation was established between the maximum luminescent emission wavelengths (λ_em) of the turbid liquid in buffer solutions and the corresponding pH values in the pH range from 1 to 4. This porous material is very promising as a fluorescent probe in the rapid test systems.