Raspberry-like composite polymer particles by self-assemble heterocoagulation based on a charge compensation process.

Nano-sized poly(ethylene glycol dimethacrylate-co-acylic acid) (poly(EGDMA-co-AA)) were effectively self-assembled on poly(divinylbenzene-co-styryl methylpyridinium chloride) (poly(DVB-co-StMPyCl)) surfaces to form the raspberry-like composite by a charge compensation mechanism through the affinity complex between carboxylic group and pyridinium group. The effects of pH and salt electrolyte on the morphology of the self-assembled polymer composites were investigated. The resulting heterocoagulates were highly stable in water and acid solution. These heterocoagulates were reversible through the self-assembly in acidic or neutral media and the dissociation in the basic medium due to the charge compensation through the strong affinity complex between hydroxide anion and pyridinium group cation. The resulting heterocoagulates were characterized with scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). As a result, a new method for tuning the structure of a charge compensation directed polymer composite was developed.