Noncovalent Spiropyran Coatings for Photoinduced Wettability Switching

Figure 2

Measured absorption of a spiropyran layer on a PET foil; excitations were performed in the same sequence as shown in the legend; (a) UV exposure; inset: spiropyran-covered PET foil after first UV excitation partly shadowed with a simple mask such that only the lower left corner was covered during the exposure; (b) irradiation with blue light after UV exposure.

(a)

(b)