Dense Hydrogen-Bonding Network Boosts Ionic Conductive Hydrogels with Extremely High Toughness, Rapid Self-Recovery, and Autonomous Adhesion for Human-Motion Detection

Abstract

The construction of ionic conductive hydrogels with high transparency, excellent mechanical robustness, high toughness, and rapid self-recovery is highly desired yet challenging. Herein, a hydrogen-bonding network densification strategy is presented for preparing a highly stretchable and transparent poly(ionic liquid) hydrogel (PAM-r-MVIC) from the perspective of random copolymerization of 1-methyl-3-(4-vinylbenzyl) imidazolium chloride and acrylamide in water. Ascribing to the formation of a dense hydrogen-bonding network, the resultant PAM-r-MVIC exhibited an intrinsically high stretchability (>1000%) and compressibility (90%), fast self-recovery with high toughness (2950 kJ m-3), and excellent fatigue resistance with no deviation for 100 cycles. Dissipative particle dynamics simulations revealed that the orientation of hydrogen bonds along the stretching direction boosted mechanical strength and toughness, which were further proved by the restriction of molecular chain movements ascribing to the formation of a dense hydrogen-bonding network from mean square displacement calculations. Combining with high ionic conductivity over a wide temperature range and autonomous adhesion on various surfaces with tailored adhesive strength, the PAM-r-MVIC can readily work as a highly stretchable and healable ionic conductor for a capacitive/resistive bimodal sensor with self-adhesion, high sensitivity, excellent linearity, and great durability. This study might provide a new path of designing and fabricating ionic conductive hydrogels with high mechanical elasticity, high toughness, and excellent fatigue resilience for skin-inspired ionic sensors in detecting complex human motions.

Highly Stretchable and Reconfigurable Ionogels with Unprecedented Thermoplasticity and Ultrafast Self-Healability Enabled by Gradient-Responsive Networks

“…The formation of the gradient-responsive networks among the TPEI is vital to its unique thermoplasticity and largely enhanced mechanical robustness. Figure S4a (Supporting Information) shows the formation of hydrogen-bonded interactions between the PVA and PAAm chains within the TPEI that caused the peak shift in the Fourier transform infrared (FT-IR) spectrum. − The FT-IR spectrum of the PVA ionogel (PVA-I) had peaks at 3331 and 1092 cm –1 , which were assigned to the −OH stretching region and C–O–C symmetric stretching, respectively. For the PAAm ionogel (PAAm-I), four distinct peaks appeared at 3353, 3179, 1658, and 1615 cm –1 , which were ascribed to −NH 2 asymmetric stretching, −NH 2 symmetric stretching, and symmetric stretching of amide I and amide II, respectively. , The TPEI also showed the absorption peaks of PVA-I and PAAm-I in the FT-IR spectra.…”

A Waterproof Ion‐Conducting Fluorinated Elastomer with 6000% Stretchability, Superior Ionic Conductivity, and Harsh Environment Tolerance

“…Figure 4e displays that the G ′ values are higher than the G ″ values at a small shear strain (<300%), indicating the excellent structural integrity of ICFE‐1.5M. [ 35 ] When the shear strain further increases to 300%, the G ′ values begin to decline and are smaller than the G ″ values. The crossover point of G ′ and G ″ values reveals a critical point of solid‐liquid transition.…”

Crimped nanofiber scaffold mimicking tendon-to-bone interface for fatty-infiltrated massive rotator cuff repair

“…The fabrication and utilization of the nanofiber scaffolds (NS) and crimped nanofiber scaffolds (CNS) used via multi-bonding network densification strategy in this study are illustrated ( Fig. 1 A and B and S2) [ 28 ]. SEM images of the morphological and structural properties of NS, CNS1 (CNS immersed in the prepared crosslinking solution for 3 h), CNS2 (CNS immersed in the prepared crosslinking solution for 12 h), and CNS3 (CNS immersed in the prepared crosslinking solution for 24 h) are shown ( Fig.…”