Preparation of PAAS/GL/GO anti-freezing conductive hydrogels based on chemical cross-linking networks and their application in wearable sensors

Abstract

Conductive hydrogels have potential applications in the field of wearable devices as carrier materials for flexible strain sensors. In this work, antifreeze filler glycerol (GL) and conductive filler graphene oxide (GO) were introduced into sodium polyacrylate (PAAS) chemical cross-linking network hydrogels, and the PAAS/GO/GL antifreeze conductive hydrogels were prepared by one-pot method. The structures and properties of the hydrogels were characterized and tested. The results showed that the addition of GO improved the mechanical properties and conductivity of the hydrogel. When the addition of GO was 0.6 wt%, the tensile strength of PAAS/GO/GL hydrogel reached the maximum of 0.215 MPa, the corresponding elongation at break reached 1180%, and the conductivity reached 1.056 S·m⁻¹ at room temperature. The addition of GL resulted in good freezing resistance and moisture retention of the hydrogel, with a conductivity of 0.846 S·m⁻¹ even after freezing at −20 °C. The PAAS/GO/GL hydrogel showed good sensing performance. When the tensile deformation reached 600%, the gauge factor (GF) reached 10.82. In addition, PAAS/GO/GL hydrogel also has good self-healing and adhesion, which has potential application value in flexible wearable sensors.