A facile dual templating route to fabricate hierarchically mesostructured materials

Hierarchically mesostructured materials have been successfully synthesized via a facile route using amphiphilic block copolymer polystyrene-b-poly (acrylic acid) (PS-b-PAA) and cetyl trimethyl ammonium bromide (CTAB) as dual templates. It is found that the dimension of spherical micelle-like aggregates of PS-b-PAA could be adjusted by changing the kind of solvents. With N,N-dimethylformamide (DMF) as solvent, spherical micelle-like aggregates with an average diameter of 35 nm were obtained, and bimodal mesoporous materials (BMM) possessing large pores of ∼35 nm and small pores of 2.5 nm could be prepared. As the solvent was changed to N,N-dimethylformamide (DMF)/tetrahydrofuran (THF) (v/v = 1:1), the average diameter of the spherical micelle-like aggregates of PS-b-PAA was increased to 200 nm, and hollow mesoporous spheres (HMS) with 200-nm hollow cores and 25-nm shells were thus achieved.