Highly ordered hierarchically macroporous- mesoporous TiO₂ for thiol-ene polymer design by photoclick chemistry

Photoclick chemistry is a green, atomic economy reaction. While it is still difficult to obtain a polymer compound with well-controlled molecular weight using the click chemistry method. The ordered hierarchically macroporous-mesoporous TiO₂ show excellent photocatalytic activity in the thiol-ene reaction of polymers due to their large specific surface area. Meanwhile, the degree of polymerization and molecular weight (about 2600 amu) of the polymer can be controlled. Owing to the confinement effect of mesoporous structure in macroporous walls, which offers us a new perspective for thiol-ene polymer design by photoclick chemistry. Highly ordered hierarchically macroporous-mesoporous TiO₂ with crystalline framework walls are directly achieved via a one-pot process, and the dual templates are assembled at the same time by a solvent evaporation process. The crystalline mesoporous walls are anatase titania, and the BET surface area is up to 301 m²/g. The macroporous diameter can be manipulated by controlling the size of PS microspheres.