Synthesis of core‐shell and Janus polystyrene@polypyrrole particles by variation of surfactant and monomer amount through seeded emulsion polymerization

Abstract

Polystyrene (PS) seed particles were synthesized under similar conditions with different anionic, cationic, and non‐ionic surfactants, as well as without surfactant. The effect of surfactant type on the morphology and size of PS particles was investigated. These particles were then used as seeds in chemical oxidative polymerization of pyrrole and the effect of surfactant type and pyrrole/seed weight ratio on the morphology of the resulting composite particles was monitored. According to the results, different surface properties of PS seed particles resulted in various morphologies. Anionic surfactant led to formation of core‐shell structure because of electrostatic interactions between polypyrrole (PPy) oligomers and seed particles. However, cationic surfactant led to electrostatic repulsions between positively‐charged PPy oligomers and PS particles' surface and formation of patchy structures. Non‐ionic surfactant resulted in formation of snowman‐like Janus particles due to absence of electrostatic interactions.