Herein, we developed a synthetic approach for making HSNs
with tunable morphologies by using poly(vinylpyrrolidone)−
water droplets as the soft templates. Three morphologies with
hollow interiors, including tadpole-like, wirelike, and sphere,
were obtained easily by changing the applied solvent from 1-
propanol, to 1-pentanol, to ethanol, respectively. In addition,
we demonstrated that the molar ratio of NH4OH to TEOS and
the reaction time could also be used as factors to tune the
morphology of produced nanomaterials. The effect of various
factors on the morphology was systematically studied to
propose a growth mechanism. The potential application of the
developed hollow nanomaterials was investigated by taking the
hollow spherical silica nanomaterials (HSSNs) as an example to
study its drug-carrying ability. Using inexpensive and
commercially available reagents, the newly developed onestep
synthetic strategy shows significantly high reproducibility
that brings great potential for a large-scale synthesis