Superior, Environmentally Tolerant, Flexible, and Adhesive Poly(ionic liquid) Gel as a Multifaceted Underwater Sensor

Abstract

In recent years, gel-based sensors have been widely considered and fully developed. However, it is of vital importance, yet rather challenging to achieve a multifaceted gel, which can unify the advantages of favorable conductivity, high adhesion, excellent environmental resistance, and so forth and be applied in various harsh conditions. Herein, an ideal, extremely stable, adhesive, conductive poly(ionic liquid) gel (PILG) was designed via a onestep photoinitiated radical polymerization based on 1-vinyl-3butylimidazolium bis(trifluoromethylsulfonyl)imide (VBIm-NTf 2 ) cross-linked with ethylene glycol dimethacrylate (EGDMA) in methyltributylammonium bis(trifluoromethanesulfonyl)imide (N 1444 -NTf 2 ) medium. There are abundant hydrophobic butyl chains and fluorinated groups in VBIm-NTf 2 and N 1444 -NTf 2 , which can impart the PILG with stable conductivity, excellent environmental tolerance, and adhesion even in water due to the ion−dipole and ion−ion interactions. The resulting PILG can be assembled as a soft and smart sensor that can be applied in specific conditions such as underwater or undersea and even in dynamic water, achieving a stable signal transmission. Meanwhile, the PILG can be utilized as a flexible electrode to convey ECG signals in air or water whether it is in the static or dynamic state. Therefore, it is envisioned that this novel PILG will serve as a hopeful electrical device for signal detection and healthy management in specific environments.

Visible-Light Transparent, Ultrastretchable, and Self-Healable Semicrystalline Fluorinated Ionogels for Underwater Strain Sensing

“…The area of the hysteresis loop grows progressively with increasing cyclic strain, indicating that SFIG3 can efficiently dissipate energy via noncovalent bond breakage. 28 To confirm the self-recovery ability of SFIG3, cyclic tensile tests at a loading strain of 500% with various rest times were performed on SFIG3 (Figure 3c). The SFIG3 shows excellent self-recovery properties.…”

“…During the cyclic tensile tests, SFIG3 showed a clear hysteresis loop and only a small amount of plastic deformation. The area of the hysteresis loop grows progressively with increasing cyclic strain, indicating that SFIG3 can efficiently dissipate energy via noncovalent bond breakage . To confirm the self-recovery ability of SFIG3, cyclic tensile tests at a loading strain of 500% with various rest times were performed on SFIG3 (Figure c).…”

Double-Layer Carbon Encapsulated Co Particles Combined with Ionic Liquid for Enhancing Electrochemical Detection of Oxygen

“…With these factors taken into consideration, ionic liquids (ILs) are given more and more attention for their outstanding characteristics including high ionic conductivity, thermal stability, nonvolatility, and low vapor pressure, as well as wide electrochemical windows. − These characteristics made them suitable to be widely employed in fields of electrochemistry such as electrosynthesis, electrochemical supercapacitors, and sodium batteries, especially acting as both electrolytes and solvents simultaneously for electrochemical (gas) sensors. − There have been works reported on the O 2 reduction behavior in multiple ionic liquids in diverse concentrations, verifying the feasibility of ionic liquids acting as solvent and electrolyte simultaneously for electrochemical oxygen detectors. , Although the restrictions of traditional sensors can be avoided by utilization of ionic liquid electrolytes, challenges involving low viscosity and weak response yet remain for ionic liquid sensors. Strategies were hence developed such as modifying the ionic liquid electrolyte by introducing electroactive materials, which has recently become the preferable method.…”

Novel Uracil-Functionalized Poly(ionic liquid) Hydrogel: Highly Stretchable and Sensitive as a Direct Wearable Ionic Skin for Human Motion Detection

“…Recently, polymeric ionic liquids (PILs) have garnered tremendous attention due to their high conductivity, chemical stability, structural designability, antibacterial activity, and biocompatibility . Based on these unique physicochemical properties, PIL–polymer composites have been widely used in many fields including sensors, energy storage materials, biomedicine, eco-materials, etc. , Meanwhile, research on the preparation method and functional improvement of PIL hydrogels has also been quietly carried out. − Compared with the hydrogel prepared with ionic liquid (IL) as a solvent, the preparation of hydrogels through in situ polymerization of IL monomers has more advantages. It avoids the leakage of conventional ionic liquid-impregnated polymer hydrogel caused by deformation and retains the unique properties of PILs.…”