Double Network Glycerol Gel: A Robust, Highly Sensitive, and Adaptive Temperature Sensor

Abstract

Temperature sensors have great potential applications for the body temperature monitoring, it's a big challenge to prepare sensors with high sensitivity and maintaining adaptive properties for the long‐term applications. In this study, an organohydrogel for the temperature sensor is achieved via glycerol solvent replacement of water in the poly‐N‐acryloyl glycinamide (PNAGA)/carrageenans double network (DN) hydrogel. Owing to successful construction of strong multiple hydrogen bonding (H‐bonding) interactions among PNAGA chains and carrageenans, the PNAGA‐based glycerol gel (Gly‐gel) sensor exhibits excellent thermal stabilities, possesses high sensitivities (2% °C) resulted from the acceleration of mobility of ions at high temperature and shows high tensile strength of about 4 MPa without chemical crosslinkers (higher than most reported organohydrogel‐based temperature sensor) with self‐healable performance. In addition, the double network of Gly‐gel enables it excellent dual and triple shape memory performance with high fixing ratio (Rf, 88%), recovery ratio (Rr, 95%) under large deformations (above 80%) that are beneficial to the potential application in wearable devices. Different from previous temperature sensors, this work provides a facile approach to prepare overly sensitive temperature sensors with the combination of excellent thermal stability, high tensile strength and adaptive properties via the solvent replacement of hydrogel.

Unlocking the Power of Multicatalytic Synergistic Transformation: toward Environmentally Adaptable Organohydrogel

“…[51] The LAlNPsOH organohydrogel formulation containing glycerol adds further hydrogen bonding to the system and therefore increases its durability (Figure 4d). [52] We made an initial investigation on the hypothesis that the Ag + /Ag 2+ catalytic system might promote the free radical crosslinking reaction in the presence of APS in the LAgNPsOH gel. It is well known that APS can oxidize Ag + to Ag 2+ .…”

Conductive and Eco-friendly Biomaterials-based Hydrogels for Noninvasive Epidermal Sensors: A Review

“…Body temperature, the essential physiological parameter, provides real-time sensing for monitoring human vital signs. 190 Available research tends to increase the durable water retention and low-temperature tolerance of sensors by introducing glycerol (enhanced hydrogen bonding interfacial interactions) 191,192 and to improve their mechanical properties by introducing cellulose. 193,194 Wu et al 195 arranged glycerol (Gly) to partially replace the water in the hydrogel by solvent substitution method to optimize the thermal sensitivity (19.6%/°C) and stability (regular operation at −18 to 70 °C) of the sensor.…”

“…Body temperature, the essential physiological parameter, provides real-time sensing for monitoring human vital signs . Available research tends to increase the durable water retention and low-temperature tolerance of sensors by introducing glycerol (enhanced hydrogen bonding interfacial interactions) , and to improve their mechanical properties by introducing cellulose. , …”

Recent developments of polysaccharide‐based double‐network hydrogels

“…The coil–helix structural transition of CG and hydrogen bonding between the two networks endowed the hydrogel self‐healing ability. Feng et al 99 reported an organohydrogel for the temperature sensor by a solvent replacement process (Figure 7B). Due to the multiple hydrogen bonds between poly‐N‐acryloyl glycinamide (PNAGA) chains and CG, CG/PNAGA DN hydrogel showed high tensile strength, sensitivity to temperature, self‐healing ability, and shape memory performance.…”

“…Copyright Elsevier 2019 (B) preparation and network structure of CG/PNAGA hydrogel. Reproduced with permission 99 . Copyright Wiley 2021…”