Formation of polystyrene nanoparticles with a core–shell contrast by surfactant-free emulsion polymerization and thermal annealing

Key Points

• The aim is to understand how different solvents and initiator ratios affect the formation of polystyrene nanoparticles with core-shell structures.
• Utilized soap-free emulsion polymerization in water with an organic solvent.
• Applied thermal annealing under reflux to modify the nanoparticle structure.
• Varying the solvent type and initiator/monomer ratio to assess their impact on particle characteristics.
• Successfully formed polystyrene nanoparticles with distinct core-shell contrast observed via TEM.
• Core size varied based on the type of solvent used.
• Increased initiator/monomer ratio led to a decrease in particle size.
• Maintained tunable internal contrast across various particle sizes.