Figure 3. DPD simulations of 16-arm star-shaped polymers of varying arm lengths and the formation of different emulsions.

For 16-arm PLLAs, as the length of the polymer arm decreases from 120 to 10, the structures undergo a transition from non-hollow (N_bead=120, a, b) to hollow (N_bead=40, c, d) to spongy (N_bead=10, e, f). This occurs for a variety of polymer droplet concentrations and in other star polymer systems with different arm numbers. The left column of images (a, c, e) shows the polymer isosurface, with individual hydroxyl beads on the bottom half of the droplet shown in red. The conformation of a single 16-arm PLLA is shown in the square box. The right column (b, f, j) shows the internal structure of the same droplet in the left, with glycerol in purple. Some hydroxyls (red beads) are removed for clarity.