Integrated Simulation System for Soft Materials.

A simulation of polymer phase separation associated with solvent evaporation was conducted using COGNAC (DPD). Two polymer components, a solvent, and a gas phase were represented by DPD particles, and the evaporation phenomenon was represented by the solvent components moving into the gas phase region and changing into gas phase components.

For simplicity, Figure 1 shows only the two polymer components in yellow and red. The two components, which were mixed in the initial state due to the presence of the solvent, formed a phase-separated structure as the solvent evaporated. As a result, first, a phase-separated structure formed parallel to the substrate, and finally, a phase-separated structure formed perpendicular to the substrate.

It is also possible to evaluate the phase-separated structure changed with conditions, for example, interaction between components, evaporation rate of solvent, and wettability to the substrate. See Reference (1) for details such as calculation conditions.

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