Crystallization-Driven Hierarchically Ordered Polymer Nanoparticles

Polymer nanoparticles have found broad applications ranging from biomedical, food industry, agriculture, to cosmetics. Hierarchically ordered polymer nanoparticles are of particular interest since they allow for exquisite control over particle structure and functions. In this work, poly(L-lactic acid) (PLLA) and PLLA-based block copolymers are controlled to crystallize at spherical oil/water interface of emulsion droplets. The resultant polymer nanoparticles are named crystalsomes. The crystalline packing and block copolymer ordering within the curved crystalsome shells (intra-crystalsome ordering), rendering its hierarchically ordered nature. Further assembly of these crystalsomes leads to unique colloidal crystals at a higher length scale (inter-crystalsome ordering). This presentation will cover particle growth mechanisms, hierarchical ordering, and supraparticle packing, systematically investigated using microscopy and scattering techniques.