Systematic study on evolution of self-assembly morphologies of CABC tetrablock terpolymers with varied segment lengths

The self-assembly structures of PEEA-PMMA-PGLMMA-PEEA CABC-type tetrablock terpolymers with a fixed length of the PGLMMA segment and varied lengths of the PMMA and PEEA segments were systematically studied, where PMMA is poly(methyl methacrylate), PGLMMA is poly(glycerol monomethacrylate), and PEEA is poly(2-(2-ethoxyethoxy)ethyl acrylate). The morphological evolution from spherical flower-like micelles to discs, toroids, and porous structures was demonstrated by tuning the lengths of the PEEA and PMMA segments. Two smart toroids were also synthesized. One is the temperature-directed morphology-changeable toroid. The temperature-responsiveness of the PEEA segment enabled a reversible morphological transformation from toroids to spherical star-like micelles. The other is the crosslinked toroid. The toroid was successruflly crosslinked, and the crosslinked toroid enabled the change in the hole size of the toroid in response to temperature. The obtained toroids (uncrosslinked and crosslinked) may serve as red blood cell-like containers in delivery applications, act as ring-shaped molecular templates in material design, and also be used in stimuli-responsive systems.