When 1-propanol was used as the solvent, although it is also
miscible with H2O, the combined solution was far from
homogeneous.35 In this case, some produced H2O molecules
would prefer binding with PVP rather than dispersing into the
surrounding solvent. Thus, the surface tension of PVP−H2O
droplets would be changed. As the anisotropic supply
continued to hydrolyze and condense, the PVP−H2O droplets
were deformed where the silica grew along, resulting in a
tadpole-like shape [Scheme 1(2)]