StOber synthesis, studies

Among metal oxide compositions, the chemistry of silica is the most widely studied and weU established, from the classical Stober synthesis of a silica sphere [23] to the recently developed surfactant-mediated synthesis of mesoporous silica [24, 25]. These developments were mainly enabled by the availability of stable silica precursors, their controllable hydrolysis and condensation, and the stable oxidation state of silica. Based on previously established chemistries, sol-gel or microemulsion methods were used to synthesize silica-shell-based core-shell NPs. 

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