Preparation of polymer particles and control of their inner structures

We have reported that a novel preparation method of polymer particles by simple good solvent evaporation from the polymer solution of the good solvent and a poor solvent. By using this method, polymer particles ranging from several tens nanometer to several micrometer can be prepared from many kinds of polymeric materials. In this report, we show the preparation of block-copolymer nanoparticles and their hierarchic structures in them. Submicrometer-sized poly(styrene-b-isoprene) particles were prepared by using our method. Observing by using scanning transmission electron microscope (STEM), various kinds of micro-phase separation structures were formed depending on their polymer segment ratio and polymerization ratio.