In another field, inorganic hollow spheres have increasingly
attracted interest because of their potential applications in catalysis,
controlled delivery of drugs, artificial cells, light fillers, low dielectric
constant materials, acoustic insulation and photonic crystals [11,12].
In recent years, the use of polymer template particles to fabricate such
hollow spherical structure of inorganic materials has proven to be
very successful [13–15]. However, it is generally difficult to synthesize
the titania-coated particles because the titania precursors are highly reactive,
making it difficult to control their precipitation [16]. This property
of the precursors easily causes the aggregation of the core particles or
the formation of separate titania particles without cores. To overcome
this difficulty, Li and Zhang utilized sulfate-stabilized PS particles as a
template in conjunction with the sol–gel methods [17].