This Progress Report describes the latest advances in vesicles and liposomes. Recent work on the self‐assembly of complex polymer systems shows that the formation of polymer vesicles or closed hull structures is archetypal, leading to fascinating new possibilities and applications in materials science. A general view of the underlying self‐assembly mechanisms leading to vesicles and the control of size, shape, and other vesicular properties by physicochemical means is presented, as background. This is followed by an overview of the recently described new classes of polymer and supramolecular tectons that make vesicle formation a more general phenomenon going beyond just lipids. Finally, the potential applications of vesicles, including non‐lipid vesicles, are outlined.

The phase behavior of ten polyisoprene-polystyrene (PI-PS) diblock copolymers, spanning the composition range from 0.24 to 0.82 polyisoprene volume fraction (/pi), has been studied near the order-disorder transition (ODT). Dynamic mechanical spectroscopy, transmission electron microscopy, and neutron and X-ray scattering have been used to characterize phase transition temperatures and ordered state symmetries. Five distinct microstructures were observed for this chemical system: spheres, hexagonally packed cylinders (HEX)_, lamellae (LAM), hexagonally perforated layers (HPL), and a bicontinuous cubic phase having an Ia3d space group symmetry. The bicontinuous Ia3d phase only occurs in the vicinity of the ODT between the HEX and LAM states at compositions of 0.65 £ /pi £ 0.68 and 0.36 £ /pi £ 0.39 (prior report). Farther from the ODT, within these composition ranges, the HPL phase occurs.We did not find the ordered bicontinuous double diamond (OBDD) morphology at any composition or temperature studied, and the overall phase diagram is qualitatively different from those reported previously for PI-PS block copolymers.

Amphiphilic block copolymers (ABCs) are important in interface and particle stabilization. Following consideration of the various methods of synthesis of ABCs, mesophases and micelles of block copolymers and the solubilization and adhesion of ABCs are considered. The Figure shows micelles formed by a polystyrene‐poly(vinylpyridine) copolymer. Nanoparticles and ABC/nanoparticle hybrid systems are also reviewed.

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