Electrochromic Metallo-Supramolecular Polymers with Memory Effect

① Prepare two ITO glasses (glasses coated with ITO) (Size: 10 × 10 cm; Sheet resistance: <10 Ω/sq)

② Coat Poly(Fe-btpyb) Purple on ITO glass either by spray or spin coating the methanol solution (3 mg/mL)^*2*3

^*2 An uncoated part (5-10 mm) is required to connect with a battery

^*3 Counter layer is prepared on another ITO glass, if needed ²⁾

③ Load the gel electrolyte^*4*5 on another ITO glass and spread it uniformly^*6

^*4 A mixture of LiClO₄ (1.5 g), propylene carbonate (10 mL), and PMMA powder (10 g) (Degassing by stirring the gel for 2 h at rt under reduced pressure is recommended before use)

^*5 Amount: 10-20 g

^*6 An uncoated part (5-10 mm) is required to connect with a battery

④ Bond the two glasses of ② and ③ together so that the Poly(Fe-btpyb) Purple layer and the gel electrolyte layer face each other^*7

^*7 Bond the two glasses of ② and ③ together so that the Poly(Fe-btpyb) Purple layer and the gel electrolyte layer face each other

⑤ Clip the stacked glasses and anneal it for 5 min at 100 ºC

⑥ Remove the clips to obtain the electrochromic (EC) device

① Prepare two AA batteries, a battery holder, and two alligator clips

② Connect the series-connected batteries to two bear parts of the ITO glasses using the alligator clips.^*8

③ The original purple color disappears when (+) of the battery is connected to the ITO glass coated with Poly(Fe-btpyb) Purple.^*8

^*8 Power off once the color change ends, to prevent the degradation of the device

An image can be displayed on the device when a transparent film with the image cut is put on a Poly(Fe-btpyb) Purple layer during the device fabrication.^*9

^*9 The film-coated part does not show any color changes, because the film prevents anion transfer to the Poly(Fe-btpyb) Purple layer.

All the pictures and deta were provided by National Institute for Materials Science (NIMS), Japan.