Stretchable, conductive poly(acrylamide‐co‐maleic acid)/triethylene glycol/NaCl double‐crosslinked organohydrogel with excellent antifreezing and sensing properties

Abstract

Recently, the wearable electronic devices have attracted extensive attention while the low stretchability and freezing-induced performance deterioration largely limit the applications in many fields. In this work, the poly(acrylamide-co-maleic acid) hydrogels are immersed in the triethylene glycol/sodium chloride/water solution to establish the dual-crosslinked organohydrogels, which present the extraordinary stretchability (1322 ± 75%) ascribed to the energy dissipation of physical interactions and stability of chemical crosslinked networks. Triethylene glycol forms strong hydrogen bonds with water, which interfere with the formation of intermolecular hydrogen bonds among water molecules at low temperatures and inhibit the formation of ice crystals in the organohydrogel networks.Sodium chloride imparts excellent electrical conductivity to the organohydrogel. As a result, a stretchable electronic sensor based on the organohydrogel is fabricated, which is strain-sensitive with a wide strain sensing window (0%-440%) and excellent stability. More importantly, the sensor based on the as-prepared organohydrogel could precisely detect various activities of the human model at À30 C leading to the widely application prospects.

Stretchable Semi-Interpenetrating Carboxymethyl Guar Gum-Based Composite Hydrogel for Moisture-Proof Wearable Strain Sensor

“…The gauge factor (GF) of is estimated by eq : , GF = false( R − R 0 false) / false( R 0 ε false) where ε was the applied strain.…”

Hydrogel Bioelectronics for Health Monitoring

“…Wang, Lai, Li, and Wu et al reported a ionic conductive hydrogel ( Figure 6 A), which was a dual-crosslinked organohydrogel fabricated by immersing the poly(acrylamide-co-maleicacid) hydrogels in triethylene glycol/sodium chloride/water solution with electrical conductivity and excellent stretchability (1322 ± 75%), even at low temperature [ 44 ]. Sun and He et al reported a ionic zwitterionic nano-micelle hydrogel, which was fabricated via in situ co-polymerization of zwitterionic monomer SBMA and nonionic monomer-hydroxyethyl methacrylate (HEMA) using Pluronic F127 di-acrylate (F127DA) as macro-crosslinkers ( Figure 6 B) [ 45 ].…”

“… ( A ) Schematic illustration of ionic conductive hydrogels’ formation, structure, and intermolecular interactions. Reproduced with permission from Wiley-VCH, copyright 2022 [ 44 ]. ( B ) Schematic illustration of the fabrication process of the nano-micelle zwitterionic hydrogels.…”