Studies on evolution of crystal patterns of single-layer lamellae of three star-shaped poly(ethylene oxide)s (PEO) samples with 3

4 and 8 arms and a 5000 molecular weight for each arm and a 5000 linear PEO sample were reported.With increasing crystallization temperature the dendritic-to-seaweed and seaweed-to-faceted crystal pattern transitions in these samples were observed.Plotting the transition temperatures with the arm number generated a morphology diagram that clearly reflected the effect of macromolecular topology on the crystal pattern formation and selection.Increasing the arm number of the star-shaped PEOs results in a topological change from an anisotropic line to an isotropic sphere

so the molecular motion also alters from a sliding motion of linear macromolecules to a coordination motion of star-shaped macromolecules.These changes further affect the two key issues of crystal pattern formation:the diffusion and crystallization of macromolecules

so the crystal pattern formation and selection of star-shaped macromolecules depend on their molecular topology.