Polymer Crystallization in Nanoemulsion Systems

Polymer crystalsomes are a new type of polymeric nanoparticles, which can form by crystallization at curved liquid/liquid interface of nanoemulsions. Previous work showed the polymer shell is single-crystal-like with a splayed lattice wrapped into a spherical shell whose size ranges from 100nm to several micrometers. The highly dynamic nanoemulsion system offers a unique opportunity to control further the crystalsome size, size distribution, and morphology, which are essential for their end applications. In this work, using poly(lactic acid) (PLA) as an example, we demonstrate that while polymer crystallization is confined mainly in the emulsion droplets, inter-droplet interaction, which often manifests itself as droplet coalesce or Oswald ripening, can also alter polymer crystallization pathways. Stabilizing nanoemulsion can lead to much-improved polydispersity of the crystalsomes. Possible polymer chain exchange was followed by blending nanoemulsions formed by the R and S enantiomer of PLA nanoemulsions. Our results reveal that nanoemulsion is a versatile platform for fabricating functional polymer nanoparticles and advancing our understanding of polymer crystallization.