Preparation of Raspberry-like Polymer Particles by a Heterocoagulation Technique Utilizing Hydrogen Bonding Interactions between Steric Stabilizers

Large polystyrene particles stabilized by poly(acrylic acid) (PAA) (L-PSPAA) (as the core) and small polystyrene particles stabilized by poly(vinyl pyrrolidone) (PVP) (S-PSPVP) (as the corona) were successfully used to prepare raspberry-like particles by a heterocoagulation technique utilizing the hydrogen bonding interaction between PAA and PVP. The coverage of L-PSPAA by S-PSPVP could be controlled by adding PVP homopolymer to the L-PSPAA dispersion and by changing the molecular weight of the stabilizers. Moreover, the heterocoagulation of large poly(methyl methacrylate) particles stabilized by PAA (L-PMMA(PAA)) and S-PSPVP particles was also accomplished, resulting in the formation of L-PMMA(PAA)-core/S-PSPVP-corona raspberry-like composite particles. These results suggested that the raspberry-like particles composed of various polymer particles could be formed by the heterocoagulation technique utilizing the hydrogen bonding interaction.