Internal Morphology-Controllable Self-Assembly in\nPoly(Ionic Liquid) Nanoparticles

Abstract

Precise\ncontrol of the interior and outer shapes of polymer nanoparticles\nhas found broad interest in nanosciences, for example, in fundamental\nstudies of their physical properties, colloidal behavior, and corresponding\napplications. Realizing such control below the 50 nm scale (<i>i.e.</i>, a size scale close to individual polymer chains) requires\naccurate manipulation of polymerization techniques and a judicious\nchoice of the chemical structure in monomers and/or polymers. Here,\nwe constructed a series of well-defined sub-50 nm homopolymer nanoparticles\nwith controllable shape and highly ordered, complex internal structures\nwith sub-5 nm domain spacings, starting from 1-vinyl-1,2,4-triazolium-type\nionic liquids in a one-pot dispersion polymerization. With cryogenic\nelectron microscopy and tomography, a morphological evolution of particle\nshape and interior at this extremely small size end, unusual for polymer\ncolloids, was identified and investigated in detail.