Anisotropic nanoparticles have potentially various important applications, especially in 3D printing materials, binders and phase compatible agents, for which it is essential that the components and the structures are well designed and controlled. This paper investigated nanoparticles consisting of two lobes with opposite properties. As a model system, synthesis of poly(styrene-co-acrylic acid)/polystyrene anisotropic nanoparticles was studied and the effects of temperature, surfactant amount, inhibitors, and initiators for the involved polymerization procedures, and the swelling temperature, and swelling ratio for making the second lobe, on the morphology and size of the produced particles , were investigated. As a result, the anisotropic nanoparticles with uniform asymmetry, one lobe with hydrophilicity and the other with hydrophobicity, were successfully realized. The apparent size of the nanoparticles was below 200 nm, and the strategies for achieving various morphologies, such as snowman-like, potato-like and dumbbell-like, were established. The anisotropic nanoparticles achieved in this study are very useful in the 3D material development that is involved in our another research.

Keywords: snowman-like; anisotropic nanoparticles; 3D printing materials; hydrophilicity; hydrophobicity