Nanostructured polymer composite nanoparticles synthesized in a single step via simultaneous ROMP and ATRP under microemulsion conditions

Ring‐Opening Metathesis Polymerization (ROMP) and Atom‐Transfer Radical Polymerization (ATRP) were carried out simultaneously under microemulsion conditions with 1st generation Grubbs catalyst playing a double role: ROMP initiator and ATRP controlling agent. Starting from two distinct microemulsions—one containing the monomers and the other the catalyst—well‐defined composite nanoparticles with z‐average hydrodynamic diameter smaller than 50 nm were prepared. Depending on the monomers droplet composition, homopolymers blends or graft‐copolymers were synthesized in a one‐pot, one‐step, one‐catalyst approach.