Hollow nanospheres are peculiar nanoparticles featured by an inner cavity . They are characterized by a high specific surface, a high porosity, a high mechanical stability, and nanocontainer-type functionalities. Based on these features, hollow nanospheres are very interesting for catalysis, gas sorption, drug delivery, etc. .
As a straightforward access to hollow nanospheres – especially with diameters of 10 to 50 nm – we could establish a microemulsion (ME)-based synthesis strategy [1a]. In fact, MEs turned out as ideal for obtaining nanosized hollow spheres since their size directly correlates to the micelle diameter. The thermodynamical stability of MEs and the uniformity of the micelle diameter are additional assets for hollow-nanosphere synthesis [1a]. To obtain hollow nanospheres, the reactants are separately added to the polar droplet phase and to the non-polar dispersant phase.
Based on the ME-based strategy, we could prepare a wide range of hollow nanospheres (e.g., g-AlO(OH), La(OH)3, ZnO, Fe2O3, SnO2, TiO2, ZrO2, CuS, Cu1.8S, Cu2S, MgCO3, Gd2(CO3)3, Ag2S, Au, Ag) with outer diameters of 10–50 nm, a wall thickness of 2–10 nm and an inner cavity ranging from 5 to 30 nm in diameter [1a,2,3]. The as-prepared hollow nanospheres shown unique performance in view of catalyis (e.g. CO oxidation ), sensing (e.g. H2 detection ) and drug delivery (e.g. tuberculosis therapy or synergistic chemical/physical tumor treatment ). This presentation will address the ME-based synthesis as well as the properties and performance of hollow nanospheres.
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