Crosslinked 1,2,4-triazolium-type poly(ionic liquid) nanoparticles.

In this work we studied covalently crosslinked poly(ionic liquid) nanoparticles synthesized via aqueous dispersion polymerization of 1,2,4-triazolium ionic liquid monomers in the presence of a dication crosslinker. Compared to their non-crosslinked counterparts, the nanoparticles showed improved structural integrity in organic media. Assisted by cryogenic electron microscopy, these nanoparticles were analyzed in detail and found to present vastly diverse shapes and highly ordered inner mesostructures. Upon altering the length of the alkyl substituents on the triazolium cation from dodecyl to tetradecyl and hexadecyl, a shape transformation from elongated “nanoworms” to a mixture of “onion-like” and “wasp-like” nanoparticles was observed. Additionally, the size variation of these colloidal nanoparticles was investigated systematically by polymerizations at different concentrations of monomer, external added salt and crosslinking agent. Finally, the crosslinked poly(ionic liquid) nanoparticles were able to readily disperse multi-walled carbon nanotubes in water and organic media. [ABSTRACT FROM AUTHOR]