Tailored Polymer Particles with Ordered Network Structures in Emulsion Droplets.

The structural control of block copolymer (BCP) particles, which determines their properties and utilities, is quite important. Understanding the structural relationship between solution-cast samples and polymer particles in a confined space is necessary to precisely regulate the internal structure of polymer particles. Therefore, a facile method by choosing an appropriate selective solvent is reported to prepare spherical polymer particles with ordered network structures. The rod-coil BCP, poly(dimethylsiloxane)--poly{2,5-bis[(4-methoxyphenyl)-oxycarbonyl]styrene} (PDMS--PMPCS), was chosen as a model polymer because of its strong phase segregation ability. First, the structures of the BCP with a thermodynamically stable lamellar structure cast from different selective solvents were systematically studied. Then, a polymer particle with the same internal structure as that of the solution-cast sample can be easily prepared by self-assembling in an emulsion confined space. The relatively large particle size is of importance in this process because the large value of the particle size to periodicity ratio can provide a weak confined environment. This method helps us understand the inherent self-assembling mechanism of polymer particles in an emulsion confined space and accurately control the internal structure of the polymer particle obtained.