Core-shell octa(azidopropyl) POSS-PEO micelle via “click” chemistry

An amphiphilic OAPS-PEO was synthesized by “click” reaction between octa(azidopropyl) POSS (OAPS) and propargyl-terminated PEO. The structure of OAPS-PEO was characterized by nuclear magnetic resonance (NMR). The amphiphilic properties and aggregation process of OAPS-PEO in aqueous solution were investigated by fluorescence, dynamic and static light scattering (DLS and SLS), and transmission electron microscopy (TEM). The critical aggregates concentration was determined at ~ 0.10 mg/mL using fluorescence measurements. At this concentration, unassociated unimolecular micelles with diameter size of 40-50 nm were found by DLS, and were also studied by means of TEM. At a lower concentration, all the OAPS-PEO self-assembled into loose balls. With the increase of the OAPS-PEO polymer concentration, OAPS centralizes to be the core of the aggregates. At the concentration of 2.0 mg/mL, aggregates present to be a core-shell structure.