Constructing guar hydroxypropyltrimonium chloride continuous segregated network structure for preparation of biobased conductive film.

Stretchable bioelectronics advancements have placed higher demands on conductive elastic film. However, the high conductivity of elastomers largely relies on the substantial content of costly conductive fillers while being environmentally unfriendly. Herein, in order to achieve a win-win situation for the economy and the environment, guar hydroxypropyltrimonium chloride (CGG) was introduced in epoxy natural rubber (ENR) to prepare biobased conductive film. During film-forming, CGG is selectively fixed around the latex particles, thereby forming a continuous segregated network. This structure can be transformed into nanofluidic channels upon hygroscopic, resulting in low volume resistance of 211 Ω·cm (≈280 times decrease). Simultaneously, the toughness of the film is increased to 10.8 MJ/m³ (≈20 times increase) due to the "reinforced concrete structure" effect of the network of CGG. Notably, the presence of segregated network also improved the response to strain (gauge factor of 19.1) and humidity (relative resistance change of 95.9 %). Therefore, the material can be used as wearable flexible sensors. This study not only reveals the formation process of segregated structures in detail but also has significantly advanced our comprehension of biosourced conductive film.