Hydrophilic interface-crosslinked polymer micelles: a platform for nanoreactors and nanocarriers

Abstract

A poly(ethylene glycol)-b-poly(2-(2-bromoisobutyryloxy)ethyl methacrylate)-b-poly(tert-butyl acrylate) (PEG-b-PBIEM-b-PtBA) triblock copolymer self-assembles into micelles with an ATRP initiator residing at the interface. Interface cross-linked (ICL) micelles were prepared by interfacial atom transfer radical coupling (ATRC) reaction. The structure of the ICL micelles was characterized by ¹H NMR, transmission electron microscopy (TEM) and dynamic light scattering. After hydrolysis of PtBA in the cores, hydrophilic ICL micelles with PEG in the coronae and poly(acrylic acid) in the cores were obtained. The hydrophilic ICL micelles were used as nanoreactors for the preparation of inorganic nanoparticles and nanocarriers for small molecular compounds. CdS quantum dots were prepared in the cores of the micelles. The morphology and optical properties of the quantum dots were studied by TEM and UV-vis, respectively. The hydrophilic ICL micelles were also used as nanocarriers for the absorption of methylene blue, a positively charged dye. The absorption kinetics study demonstrates that the cross-linked interfaces do not limit the diffusion of methylene blue molecules into the cores of the hydrophilic ICL micelles.