Supramolecular Micelles Constructed by Crown Ether-Based Molecular Recognition

A novel supramolecular amphiphilic polymer constructed by crown ether-based molecular recognition has been fabricated and demonstrated to self-assemble into core-shell supramolecular micelles in water. The reversible transition between assembled and disassembled structures can be achieved by changing the pH. This transition was used to realize the controlled release of small molecules. The supramolecular micelle was characterized by various techniques including conductivity, transmission electron microscopy (TEM), dynamic laser light scattering (DLS), and fluorescence titration. TEM images showed dark gray spherical aggregates, and the mean size of the micelles was 50 nm in diameter and of uniformly dispersed size, in good agreement with the DLS results. The release of hydrophobic molecules from the micelles was realized by adding acid (aqueous HCl), weakening the host-guest interactions and leading to disassembly of the supramolecular micelles.