| 초록 |
We present the light-driven active shapeshifting of block copolymer (BCP) particles. The key strategy is the design of azobenzene-grafted Au nanoparticles (Au@Azo NPs) as light-responsive surfactants through photoisomerization of azobenzene ligands. In this way, visible light induced formation of onion-like spherical polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) BCP particles due to the non-polar nature of trans-Azo ligands, while the UV-induced isomerization to polar cis-Azo isomers caused transformation of the spheres to ellipsoidal BCP particles. This light-driven shape change was fully reversible over multiple cycles of irradiation with UV/Vis light. The shape evolution process was captured using a cryogenic electron microscope. Finally, light-dependent fluorescence of these hybrid BCP particles was successfully demonstrated, translating the change in particle shape into an optical signal. |
