pH-Sensitive Nanocontainers

Water-soluble polyelectrolyte nanocapsules can be synthesized by vesicular or emulsion polymerization via core–shell latexes. These particles show a reversible pH- and ionic strength-dependent swelling transition causing a considerable increase (decrease) of their radius. During this transition gated pores are opened (closed) in the spherical polymer shells, which enable free molecular exchange between the interior of the hollow sphere and the bulk medium. This pH-switchable control of the permeability of the polyelectrolyte envelopes can be used to trigger the release of encapsulated materials from their central cavity.