A facile method to fabricate tough hydrogel with ultra‐wide adjustable stiffness, stress, and fast recoverability

Abstract

In this article, we report a synergistic strategy to develop dual physically cross‐linked tough hydrogels via one‐pot bulk copolymerization of N‐vinyl‐2‐pyrrolidone, acrylic acid, and stearyl methylacrylate (SMA) without any adscititious surfactant. Due to synergic effects of hydrogen bonding and hydrophobic association, the resulted dual physically cross‐linked hydrogels (DP Gel) with ultra‐wide range adjustable Young's modulus (0.08–45.6 MPa), tensile stress (0.7–6.9 MPa), and toughness (3.3–23.1 MJ m−3). Stretching to 300%, DP Gel exhibited fast recoverability that remained ~95% of initial dissipated energy after resting in 60 °C for 3 min. Finally, scanning electron microscopy revealed that the microstructure of hydrogel changed from phase separation structure to micro phase separation as SMA added, which accounted for excellent performance of DP Gel. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1469–1474

Achieving High-Speed Retraction in Stretchable Hydrogels

“…1,11 There also have been efforts to synthesize polymeric hydrogels with high stretchability and resilience, but many of the synthesis schemes require complex reaction routes that limit their large-scale applicability. 9,10,[12][13][14] Furthermore, although many of these systems display high stretchability, a significant energy dissipation during cyclic loading is observed. 9,10,[12][13][14] None of these hydrogels have been tested for the retraction behavior from a stretched state, however, the dissipation of energy observed in these gels is expected to cause a lower retraction velocity, which will defeat the very purpose of their applications for power amplification.…”

Dual‐responsive shape memory hydrogels with self‐healing and dual‐responsive swelling behaviors

“…Inspired by the synergy mechanism of the DN structure, dual physically cross-linked (DPC) hydrogels were designed, prepared and also received extensive attention recently. [35][36][37][38][39][40][41] Different from PDN hydrogels, DPC hydrogels are composed of a single network formed by two totally different physical interactions. The DPC strategy could provide a convenient and effective method to design and prepare hydrogels with outstanding mechanical and shape memory performances.…”

A Stretchable Capacitive Strain Sensor Having Adjustable Elastic Modulus Capability for Wide‐Range Force Detection

“…To attain adjustable modulus, various promising methods are reported in the literature: structural design, [21][22][23][24][25][26] designing of composite materials, [27,28] and chemical synthesis method. [29] Maziz et al and Kharkova et al used a structural design method based on weaving and knitting and obtained adjustable modulus strain sensors made up of electroactive polymers. [30,31] Jang et al achieved adjustable modulus by using a low-modulus matrix structurally reinforced with an open, stretchable network of hard and soft structural composites.…”

“…The liquid metal (LM) core of these fibers broke continuously with the increasing of applied stress and the load-bearing capacity of those fibers did not exceed 7 N. [28] Furthermore, Dong et al obtained an adjustable elastic modulus from 0.08 to 45.6 MPa, by using double physical cross-linked hydrogel (DP gel), developed by a chemical synthesis method. [29] All of these methods are suitable for manufacturing adjustable modulus materials, but these methods cannot be used to manufacture adjustable modulus strain sensors. In addition to this, a lot of methods are available for micro-force sensing, but measuring larger loads still remains a significant challenge due to the fix and low modulus of the sensor.…”

“…To attain adjustable modulus, various promising methods are reported in the literature: structural design, designing of composite materials, and chemical synthesis method . Maziz et al and Kharkova et al used a structural design method based on weaving and knitting and obtained adjustable modulus strain sensors made up of electroactive polymers .…”