Ion-conducting gel with light-controlled variable conductivity: From cyclodextrin to messenger of light

Abstract In this work, an ion-conducting supramolecular gel with light-controlled variable conductivity named αCD-Azo gel was prepared by introducing α-cyclodextrin (αCD), anionic 1-octanesulfonic acid and azobenzene into PAM-co-PAA gel system. Based on the host-guest interactions between α-cyclodextrin and anionic 1-octanesulfonic acid (and azobenzene), the light-controlled variable conductivity properties of αCD-Azo gel have been achieved. In the absence of UV light, the conductivity of the αCD-Azo gel is around 45 mS/m. When the αCD-Azo gel was irradiated with 365 nm UV light, the conductivity of the αCD-Azo gel is about 55 mS/m. Upon 420 nm Vis light irradiation, the conductivity of the gel is about 62 mS/m. Moreover, a light-controlled logic circuit constructed with the αCD-Azo gel can control small light bulbs by UV light signals. This work provides an achievable platform for achieving the photo-controlled variable resistance effect of the gel, and can also be used to achieve non-composite photo-responsive properties of polymer materials.