Stimuli-Responsive Nanolatexes: Porating Films

A new class of very stable and stimuli-responsive nanolatexes based on copolymers of reactive and stimuli responsive ionic liquid surfactants is synthesized by microemulsion polymerization to yield dispersions of 22-30 nm diameter particles. Aqueous coatings of these nanolatexes dry to form robust films that exhibit stimuli-responsiveness to certain ion exchangeable anions. The nature of the reactive ionic liquid surfactant monomers induces an ion exchange capacity in the resulting copolymers and films. Transparent films of such nanolatexes can be transformed into opaque and porous films and membranes as a stimulus-response to anion exchange. These nanolatexes are ionic nanogels that are insensitive to Debye-Hückel screening by an indifferent salt and exhibit very soft interparticle interactions, qualifying them as ideal candidates as waterborne dispersing aids; in addition, these nanogels appear to be experimental examples of osmotic nanospheres emanating from the theoretical development of osmotic brushes.