Strong flexible conductive hydrogel based on adaptive temperature and humidity characteristics

Abstract

The development of conductive hydrogels has attracted great attention due to their broad applications. In this work, based on a dual-network structure, a highly flexible and adaptive conductive hydrogel has been developed, using the catalytic polymerization method, which also obtains Poly(3,4-ethylenedioxythiophene)-poly (styrene sulfonate) (PEDOT: PSS). Upon environmental warming, the double-network-structured hydrogel featuring a LiBr solution (LiBr@PAM-SA) undergoes a gradual water loss. However, significant moisture depletion occurs only when the temperature reaches 180 °C. Notably, compared to hydrogels devoid of a LiBr solution that experiences dehydration at 120 °C, LiBr@PAM-SA hydrogels manifest a superior capacity for adapting to varying environmental temperatures. Furthermore, this hydrogel maintains 90% of its inherent conductivity after undergoing 1000 cycles of stretching and compression. Upon incorporating 1 wt% PEDOT: PSS, the conductive hydrogel (LiBr@PAM-SA) displays the smallest volume resistivity of 0.022 Ω-cm and the highest volume conductivity of 44.665 µS/cm, in comparison to the hydrogels of single-layer graphene oxide (SLGO) and AgNWs. Additionally, its light transmittance and hydrogel quality improve in environments with lower temperatures or higher humidity. Finally, this conductive hydrogel might show great potential in varied fields of dynamic environment monitoring, intelligent conductive transmission, and intelligent sensing identification.