Self‐Assembly of Stimuli‐Responsive, Thioether‐Based Bottlebrush Diblock Copolymers: Effect of Brush Side Chain Length

ABSTRACT Linear–bottlebrush (LB) amphiphilic block copolymers offer a unique platform for designing self‐assembled nanostructures with tunable responsiveness. In this study, we synthesized a series of LB copolymers incorporating oxidation‐sensitive thioether groups in the hydrophobic bottlebrush segment, while systematically varying the brush side chain length under fixed backbone length and graft density. Self‐assembly in aqueous media led to spherical particles with distinct internal morphologies, including vesicular and densely packed structures, depending on brush architecture. Disassembly triggered by hydrogen peroxide revealed that shorter‐brush LBs with internally hollow structures disassembled more rapidly, whereas longer‐brush LBs exhibited slower disassembly due to densely packed cores and limited accessibility of oxidants. These results demonstrate that the internal morphology and oxidative responsiveness of LB assemblies can be finely tuned through architectural control, providing valuable design principles for developing stimuli‐responsive nanocarriers with programmable release profiles.