Fabrication of uniform hollow mesoporous silica spheres and ellipsoids of tunable size through a facile hard-templating route

A facile hard-templating route has been successfully developed to fabricate uniform hollow mesoporous silica spheres and ellipsoids by using hematite as hard template. The outer diameter of the spherical mesoporous silica particles can be well adjusted in a sub-micrometric range (typically around 100-200nm) by selecting suitable hematite particles as core templates. The thickness of the mesoporous shell can be tuned independently at around 10nm by tailoring the amount of tetraethoxysilane and n-octadecyltrimethoxysilane mixture. Ellipsoidal hollow mesoporous silica particles are prepared as well for the first time when spindle shaped hematite particles are employed as core templates. In addition, these hollow mesoporous particles manifest high drug storage capacity (726 mg ibuprofen per gram) mainly and physically in the core part, hence justifying their promising applications as nanocarriers in drug delivery.