Fig. 5.

Evolution of light-enabled reversible self-assembly of PMAMC-capped Au NPs with retained morphology. TEM images of PMAMC-capped Au NPs after the PMAMC-capped Au NPs CH₂Cl₂ solution (c = 8.3 μM) was exposed to (A–D) 365-nm UV light and (E and F) 254-nm UV light for a given time. The corresponding time-dependent UV–vis spectra are shown in Fig. 3 A and B, respectively. It is worth noting that images (E and F) were obtained by subsequent 254-nm UV light irradiation on the PMAMC-capped Au NPs CH₂Cl₂ solution after it was previously irradiated by 365-nm UV light for 24 h. The 365-nm UV exposure times are (A) t = 0 min, (B) t = 60 min, (C) t = 120 min, and (D) t = 180 min. The 254-nm UV exposure times (E) t′ = 5 min, (F) t′ = 15 min, (G) t′ = 30 min, and (H) t′ = 45 min. (Scale bars: Insets, 50 nm.)