A highly efficient bionic self-healing flexible waterborne polyurethane elastic film based on a cyclodextrin–ferrocene host–guest interaction

Ren

ACS Appl. Mater. Interfaces

et al. 2021

166

Hydrogel-based flexible strain sensors have shown great potential in body movement tracking, early disease diagnosis, noninvasive treatment, electronic skins, and soft robotics. The good self-healing, biocompatible, sensitive and stretchable properties are the focus of hydrogel-based flexible strain sensors. Dual network (DN) hydrogels are hopeful to fabricate self-healing hydrogels with the above properties. Here, multifunctional DN hydrogels are prepared via a combination of host−guest interaction of β-cyclodextrin and ferrocene with dynamic borate ester bonds of poly(vinyl alcohol) and borax. Carbon nanotubes are used to endow the DN hydrogels with good conductivity. The obtained DN composite hydrogels possess good biocompatibility, stretchability (436%), fracture strength (41.0 KPa), self-healing property (healing efficiency of 95%), and high tensile strain sensitivity (gauge factor of 5.9). The DN composite hydrogels are used as flexible strain sensors to detect different human motions. After cutting, the healed hydrogels also can monitor human motions and have good stability. In addition, the hydrogel sensors may track the respiratory movement of a pig lung in vitro. This work exhibits new ideas and approaches to develop multifunctional self-healing hydrogels for constructing flexible strain sensors.

Section: Resultsmentioning

confidence: 83%

Multifunctional Self-Healing Dual Network Hydrogels Constructed via Host–Guest Interaction and Dynamic Covalent Bond as Wearable Strain Sensors for Monitoring Human and Organ Motions

Ren

ACS Appl. Mater. Interfaces

et al. 2021

166

“…As for polyurethane, the introduction of host-guest interactions also contributes to the self-healing capability of polyurethane materials. Zhang et al [24] reported that they produced a series of new selfhealing waterborne polyurethane materials modified with methylated β-cyclodextrin and specially presynthesized ferrocene-diol. When damaged, they can show great self-healing capability of 100 % (slightly damaged) or 98.54 % (severely damaged) repair effect at most.…”

Section: Host-guest Interactionsmentioning

confidence: 99%

“…Figure 4. The cooperative effect between host-guest interaction and H-bonding contributes to the selfhealing capability[24]. Sugane et al[25] reported that they obtained host-guest (cyclodextrin and adamantane) driving selfhealing thermoset polyurethane network films.…”

mentioning

confidence: 99%

Research Progress in Intrinsic Self-healing Polyurethane Materials Based on Dynamic Reversible Non-covalent Bonds

Lin

Zhou

2022

J. Phys.: Conf. Ser.

Polyurethane (PU) is a polymer with great capabilities like high elasticity, low-temperature resistance, wear resistance, and corrosion resistance. However, it will inevitably be damaged in processing or long-term use, which will shorten the service life of the material and increase the potential safety hazards. The widespread use of polyurethanes has given researchers more motivation to make polyurethanes self-healing, thereby eliminating material damage and potential safety hazards to a certain extent. This paper mainly reviews the self-healing mechanism and the research progress of intrinsic self-healing polyurethanes based on dynamic reversible non-covalent bonds, including H-bonding, metal-ligand, π-π and host-guest interactions. This paper holds that the non-covalent self-healing polyurethane can repair cracks repeatedly without adding a repair agent by introducing the above non-covalent reversible bonds into the polyurethane with good mechanical properties. Various types of reversible bonds provide a variety of options for self-healing. In addition, through the research on the preparation, mechanical properties, and self-healing ability of various self-healing polyurethanes, this paper summarizes and analyzes the prospect and existing problems of self-healing polyurethanes. In the future, researchers should focus on solving the existing deficiencies. This paper looks forward to finding a better scheme to improve the performance of self-healing polyurethanes and preparing ideal self-healing polyurethane materials that appear in the public’s field of vision. This paper is written to provide help for the research of self-healing PU and accelerate the transformation of the world to green development.

Macromol. Rapid Commun.

“…As so far we know, waterborne polyurethane, consisting of hydrophobic backbone and emulsifier (2, 2-bis(hydroxymethyl)propionic acid, DMPA), had good biocompatibility and high mechanical properties, it could be used as a polymer reinforcement. [15][16][17][18] Besides, what most people do not notice was that its molecular chain contains a large number of carboxyl anions similar to cellulose nanofiber, the latter had been reported to enhance ion conductivity by promoting counterion migration. [19] Therefore, we hoped that PU could be used to simultaneously promote the mechanical strength and ionic conductivity of hydrogel.…”

Section: Introductionmentioning

confidence: 99%

Waterborne Polyurethane Enhanced, Adhesive, and Ionic Conductive Hydrogel for Multifunctional Sensors

Zhang

Shi

et al. 2021

Self Cite

In the past two decades, ionic conductive hydrogel has attracted tremendous research interests for their intrinsic characteristics in the field of flexible sensor. However, synchronous achievement of high mechanical strength, satisfied ionic conductivity, and broad adhesion to various substrates is still a challenge. Herein, a novel zwitterionic composite hydrogel that displayed excited strechability (up to 900%), satisfied strength (about 30 kPa), high ionic conductivity (1.2 mS cm−1), and adhesion to polar and nonpolar materials is fabricated though the combination of waterborne polyurethanes (PU) and poly(sulfobetaine zwitterion‐co‐acrylamide) (SAm). Especially, this facile strategy demonstrates that PU has a synergistic effect on enhancing mechanical strength and ionic conductivity for ionic conductive hydrogel. Moreover, the hydrogel‐based strain/stress sensor shows high sensitivity, wide sensing range, great stability, and accuracy for human body movements detecting and voice recognition. This novel ionic conductive hydrogel has promoted the development of wearable devices.