Reversed Surfactant Micelles as Templates for Functionalized Nanogels

Nanogels are small, highly crosslinked networks of a soluble polymer. In the case of water-soluble polymers these networks (hydrogels) can reach a very high water content by swelling in aqueous environments. The design and fabrication of functionalized nanogels as carriers of biomolecules have drawn great interests in nanotechnology and pharmaceutical applications due to their biocompatibility and useful mechanical properties. Good reproducibility and control of the nanogel size and polydispersity are essential for many of the envisioned applications.

Sodium bis(2-ethylhexyl)sulfosuccinate (AOT), one of the most widely used anionic surfactant, can form spherical reverse micelles in nonpolar liquids. These reverse micelles can be swollen to various degrees by solubilizing water in their hydrophilic core. We utilize the core of reversed micelles as nano-reactors for polymerization of functionalized nanogels. The size of the polymerized nanogel is restricted by size of the aqueous micelle core. The ratio of water to AOT in the system and the average concentrations of monomer, initiator and cross-linking agent per micelle provide a way to control the size and internal structure of the nanogel.