Synthesis and characterization of hollow mesoporous silica spheres with tunable shell thicknesses and its application in ibuprofen delivery

By using SBA-15 and RF latex with an average diameter of around 400 nm as dual templates, the hollow mesoporous silica spheres (H-SBA15) with highly ordered parallel pore size distribution centered at 3.8 nm were subsequently synthesized via modified Stober method. Meanwhile, in order to synthesis radial pore size distribution, as compared with that of H-SBA15, hollow mesoporous silica spheres (H-BMMs) were synthesized by using RF latex as a hard template and cetyltrimethylammonium bromide as a soft template. The effects of RF additives on the structural properties of H-SBA15 and H-BMMs were systematically investigated via XRD, N2 sorption isotherms, SEM, and TEM method. It was found that their tunable shell thickness could be easily controlled from 35 to 75 nm, particularly, the mesopores structures of H-BMMs were effectively tailored by adjusting ammonia dosage during sol–gel process, showing a decreasing tendency for d value of (100) peak and gradual disappearance of mesopores. Their drug-loading and releasing performances were preliminary investigated using ibuprofen as a model drug.