The Polymer Society of Korea

Abstract

In this study, we developed a BCP particle system capable of reversible and programmable shape transformation by incorporating hydrazone-based additives (Hyd) into the PS-b-P2VP. The Hyd undergoes reversible (E)/(Z) isomerization under alternating 410 and 365 nm light, which in turn controls its light-triggered quaternization with P2VP domains. This enables the generation of three distinct particle morphologies: a default ellipsoid in the dark, a larva-like shape under 410 nm light, and a stacked-disc structure under 365 nm light. These photoinduced morphologies are reversibly switchable during solvent vapor annealing and show excellent fatigue resistance. Importantly, the programmed shapes are stable for over 30 days in the absence of light, demonstrating structural memory for long-term information storage. Additionally, when domain-selective dyes are incorporated, the particle morphology alters FRET emission, offering both structural and functional programmability.