Solvents induce phase separation for fabrication of Janus hybrid nanoparticles: A dissipative particle dynamics simulation

Polyacrylic acid-gold (PAA-Au) Janus nanoparticles (JNPs) show a broad application prospect in many fields. However, PAA-Au JNPs are difficult to prepare and characterize due to their specific structures and properties. In this work, the self-assembly of PAA-Au NPs was investigated by dissipative particle dynamics (DPD) simulation method. It was found that PAA-Au NPs had a structure transition with changing the volume ratio of different solvents according to DPD simulation. The morphology of PAA-Au NPs varied from core–shell structure to Janus structure when the volume ratio of isopropanol increased in the system, which was confirmed by experimental results. In addition, other solvents with different ratios were studied in DPD simulation system. The results indicated that isopropanol and ethanol were the proper solvents to form PAA-Au Janus nanoparticles because of their unique solubility parameters. Therefore, this study reveals an optimal mixed solvent for PAA-Au NPs Janus structure and the formation mechanisms of these Janus nanoparticles.