High strength, self‐healing, and anti‐freezing polyurethane ionogel based on multiple hydrogen bonding for wearable strain sensor

Abstract

Hydrogel-based electronic skin sensors often suffer from low mechanical properties, poor durability, and low temperature resistance. Herein, an ionogel was fabricated by casting the water-borne polyurethane (WPU) and 1-ethyl-3-methylimidazoliumdicyanamide (EMIM:DCA). The imidazolidinyl urea with multiple hydrogen bonds as chain extenders was introduced into WPU systems. Owing to the multiple hydrogen bonds, the ionogels exhibited good mechanical properties with a tensile stress of 1.45-12.09 MPa, a strain of 730%-860%, and good resilience. Moreover, the mechanical properties, conductivity, and sensing ability of the ionogels could be conveniently healed with the assistance of heat. EMIM:DCA endowed the ionogels with excellent ionic conductivity at room temperature (1.8-246 μS cm À1 ). In addition, due to the low vapor pressure of EMIM:DCA, the ionogel exhibited excellent antifreezing property at À20 C. The ionogel can be assembled into a sensor to monitor the movements of human body with good responsiveness and stability.

Preparation and characterization of hydrophilic and water‐swellable elastomeric nanocomposites

“…[1][2][3] In terms of mechanical properties, these fillers can actually absorb and transfer loads at the filler-matrix interface [1,2,4] whereas for electrical conductivity features, conductive fillers are controlled to create percolated pathways for electrons to flow within the matrix. [1,2,4] Therefore, there is an increase rate of interests of application of elastomer-fillers compositions, including; dielectrics, sensors and actuators, [5][6][7][8][9][10] flexible electronics, heat sinks and gaskets, [11][12][13][14] electromagnetic shields, [15] elastomeric quantum dots materials, [16] and many attractive areas. Over the years, water swellable elastomer (WSE) class of polymers have received great attention in academics and industry for several purposes like sealing or expandable materials used in civil constructions for avoiding water leakages in pipes and working joints in concrete, [17][18][19][20] oil and gas drilling fields [19,21,22] and water-responsive and mechanically adaptive sensors [23][24][25][26] etc.…”

High strength, self-healing sensitive ionogel sensor based on MXene/ionic liquid synergistic conductive network for human-motion detection

“…However, according to previous studies, the strength of ionogels with excessive ionic liquid content could reduce significantly. 13 Ionogels with excessively low mechanical strength are limited in use and prone to damage, reducing their service life as sensors.…”

Insights into self‐healing performance of epoxidized deproteinized natural rubber/graphene oxide composite

“…Since first presented by Manlinskii et al [5] in the 1970s, S-H materials have progressed through four generations and have been classified into extrinsic and intrinsic S-H materials. [6] In the case of intrinsic S-H materials, S-H capability was derived from supramolecular interactions, including non-covalent bonds, that is, hydrogen bonds (H-bonds), [7,8] ionic bonds, [9,10] and covalent bonds, that is, ester linkages, [11,12] disulfide bonds. [13,14] In the case of extrinsic S-H materials, S-H agents were physically added to materials and released onto damaged surfaces to conduct S-H performance.…”