Solution-Processable Porous Nanoparticles Of A Conjugated Ladder Polymer Network

Conjugated ladder polymers possess multiple stranded bonds which impart rigidity into their backbones. This rigidity can promote pi-orbital delocalization for improved electronic and optical properties, or preserve interchain void space to render microporosity. Limited solution processability, however, often impedes their practical applications. To address this challenge, nanoparticulated, cross-linked ladder polymer networks were synthesized through miniemulsion polymerization followed by ring-closing olefin metathesis. The size of the nanoparticles was constrained to similar to 200 nm, affording dispersibility in organic solvents and well-defined solution-phase optical properties. The rigid, cross-linked, and conjugated ladder-type network imbued the particles with microporosity while remaining colloidally stable without external stabilization. The nanoparticles were also processed into thin films and into freestanding composites with a polymer matrix as a proof of concept for their future application as functional materials.