Recyclable Cross-Linking of Liquid-Crystalline Polymers Grafted from Nanorod Surfaces by Atom Transfer Radical Polymerization

Anisotropic functional materials demand stable molecular alignment. Cross-linked liquid-crystalline (LC) polymers provide such stability but sacrifice recyclability due to permanent networks. Here, we introduce a hybrid design in which LC polymers grafted from nanorods give rise to pseudocross-linking behavior, enabling alignment stability without chemical cross-linking. Shear-aligned films composed solely of these hybrid nanorods show a cooperative uniaxial alignment and reversible optical anisotropy. In these films, the aligned nanorods preserve the polymer entanglement in the isotropic state, allowing mesogen alignment to recover upon cooling and producing a reversible “memory effect.” The films also remain soluble, enabling redispersion and refabrication while retaining optical anisotropy, and exhibit enhanced mechanical stiffness derived from nanorod incorporation. This approach offers a versatile pathway to recyclable yet alignment-stable LC polymer systems through synergistic coupling between inorganic nanorods and LC polymer chains.