Hydro/Organo/Ionogels: “Controllable” Electromagnetic Wave Absorbers

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(43)

Published: Sept. 6, 2022

Demand for electromagnetic wave (EMW) absorbers continues to increase with technological advances in wearable electronics and military applications. In this study, a new strategy overcome the drawbacks of current by employing co-contribution functional polymer frameworks liquids strong EMW absorption properties is proposed. Strongly polar water, dimethyl sulfoxide/water mixtures, highly conductive 1-ethyl-3-methylimidazolium ethyl sulfate ([EMI][ES]) are immobilized dielectrically inert networks form different classes gels (hydrogels, organogels, ionogels). These demonstrate high correlation between their dielectric polarity/ionic conductivity/non-covalent interaction liquids. Thus, performances can be precisely tuned over wide range due diversity stability The prepared hydrogels show good shielding performance (shielding efficiency > 20 dB) constants, while organogels moderate attenuation ability impedance matching achieve full-wave X-band (8.2-12.4 GHz) at 2.5 ± 0.5 mm. ionogels also offer effective bandwidth (10.79-16.38 GHz 2.2 mm) via prominent ionic conduction loss. short, work provides conceptually novel platform develop high-efficient, customizable, low-cost absorbers.

Language: Английский

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Strong Tough Conductive Hydrogels via the Synergy of Ion‐Induced Cross‐Linking and Salting‐Out

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 32(39)

Published: July 19, 2022

Abstract Ion is one of the most common additives that can impart electrical conductivity to insulating hydrogels. The concurrent toughening effect ions, however, often neglected. This work reports extreme hydrogels via synergistic cations and anions, without need for specific structure design or adding other reinforcements. strategy equilibrate a physical double network hydrogel consisting both multivalent cation‐ kosmotropic anion‐sensitive polymers in salt solutions induce cross‐linking salting‐out simultaneously. Both effects are proven positive boost mechanical performance original weak gel, result tough conductive gel with exceptional properties, achieving significant enhancements fracture stress, energy, ionic by up 530‐, 1100‐, 4.9‐folds, respectively. optimal stress toughness reach approximately 15 MPa 39 kJ m –2 , exceeding state‐of‐the‐art Meanwhile, satisfactory 1.5 S –1 attained. presented simple also found generalizable ions polymers, which expected expand applicability conditions involving demanding durability.

Language: Английский

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Roles of Ionic Liquids in Adjusting Nature of Ionogels: A Mini Review

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 32(32)

Published: June 8, 2022

Abstract Over the past two decades, unique features of ionic liquids (ILs) drive their exploration and exploitation in gel field endow gels with many excellent properties including thermal stability, antifreezing capability, mechanical strength, self‐healing, conductivity, antibacterial performance. As promising functional materials, ionogels have attracted remarkable interest various applications flexible electronics, energy storage, biomedical applications. This review aims to give a detailed overview recent advances developing IL‐based task‐specific ionogels. The effects ILs on ionogels’ formation structure modification promotion elevating these from viewpoint fundamental application are comprehensively discussed. different interactions also discussed between other components forming ionogels, such as hydrogen bond, electrostatic interaction, host–guest IL‐philic IL‐phobic introduced ILs’ dissolvability biomass; capability owing ILs, electrochemical ability. Finally, future challenges perspectives outlooked.

Language: Английский

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Environmentally Stable, Robust, Adhesive, and Conductive Supramolecular Deep Eutectic Gels as Ultrasensitive Flexible Temperature Sensor

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(21)

Published: Feb. 27, 2023

Abstract It is essential and of great significance to impart high mechanical performance, environmental stability, sensitivity emerging flexible temperature sensors. In this work, polymerizable deep eutectic solvents are designed prepared by simply mixing N‐cyanomethyl acrylamide (NCMA) containing an amide group a cyano in the same side chain with lithium bis(trifluoromethane) sulfonimide (LiTFSI), obtain supramolecular polyNCMA/LiTFSI gels after polymerization. These exhibit excellent performance (tensile strength 12.9 MPa fracture energy 45.3 kJ m −2 ), strong adhesion force, high‐temperature responsiveness, self‐healing ability, shape memory behavior due reversible reconstruction ability hydrogen bonds cyano‐cyano dipole‐dipole interactions gel network. addition, also demonstrate good stability 3D printability. To verify its application potential as sensor, gel‐based wireless monitor developed displays outstanding thermal (8.4%/K) over wide detection range. The preliminary result suggests promising PNCMA pressure sensor.

Language: Английский

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Rapid Gelation of Tough and Anti‐Swelling Hydrogels under Mild Conditions for Underwater Communication

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 33(1)

Published: Nov. 4, 2022

Abstract Swelling is ubiquitous for conventional hydrogels but not favorable many situations, especially underwater applications. In this study, an anti‐swelling and mechanically robust polyacrylic acid (PAAc)/gelatin composite hydrogel reported with a rapid gelation process (10 1 s) under mild conditions via the synergy of MXene‐activated initiation zirconium ion (Zr 4+ )‐induced cross‐linking, without requirement external energy input. The MXene found efficient to activate chain initiation, while Zr prone indispensable facilitating cross‐linking formed polymer chains. resulting exhibits integration exceptional properties high mechanical performance at room temperature, thanks dense hydrogen bonds between PAAc gelatin chains that enable upper critical solution temperature above temperature. Also, desirable electrical conductivity emerges in due simultaneous contribution , allowing stable signal output gel upon deformation underwater. As demonstration, communicator by harnessing as sensing module assembled, which capable wirelessly delivering messages decoder on ground Morse codes. This study provides exemplary way tough durable

Language: Английский

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Vascular smooth muscle-inspired architecture enables soft yet tough self-healing materials for durable capacitive strain-sensor

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Jan. 10, 2023

Catastrophically mechanical failure of soft self-healing materials is unavoidable due to their inherently poor resistance crack propagation. Here, with a model system, i.e., polyurea, we present biomimetic strategy surpassing trade-off between and high fracture toughness, enabling the conversion weak into yet tough material. Such an achievement inspired by vascular smooth muscles, where core-shell structured Galinstan micro-droplets are introduced through molecularly interfacial metal-coordinated assembly, resulting in increased crack-resistant strain toughness 12.2 34.9 times without sacrificing softness. The obtained up 111.16 ± 8.76 kJ/m2, even higher than that Al Zn alloys. Moreover, resultant composite delivers fast kinetics (1 min) upon local near-infrared irradiation, possesses ultra-high dielectric constants (~14.57), thus being able be fabricated sensitive capacitive strain-sensors tolerant towards cracks potentially evolved service.

Language: Английский

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Ionogels: recent advances in design, material properties and emerging biomedical applications

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(7), P. 2497 - 2527

Published: Jan. 1, 2023

This review describes the most recent developments in materials design and advanced features of ionogels, as well their emerging biomedical applications.

Language: Английский

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Strong and Tough Physical Eutectogels Regulated by the Spatiotemporal Expression of Non‐Covalent Interactions

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 32(41)

Published: Aug. 5, 2022

Abstract Physical eutectogels are appealing materials for technological devices due to their superior ionic conductivity, thermal and electrochemical stability, non‐volatility, low cost. Nevertheless, current physical suffering from weak mechanical strength toughness. Here, taking advantage of the distribution difference polyvinyl alcohol (PVA) in water deep eutectic solvents (DESs), a simple universal solvent‐replacement approach is proposed regulate spatiotemporal expression intra/interpolymer interactions prepare strong tough eutectogels. The exchange DESs with can restrengthen weakened between PVA chains water, enabling crystallize construct uniform robust polymer network. Consequently, resultant eutectogel exhibits record‐high (20.2 MPa), toughness (62.7 MJ m –3 ), tear‐resistance (tearing energy Σ42.4 kJ –2 while possessing excellent stretchability (Σ550% strain), repairability, adhesive performance. Furthermore, this strategy proven be universally applicable various species polymers, even utilized fabricate continuous conductive fibers, demonstrating potential as engineering wearable sensors.

Language: Английский

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Organogels versus Hydrogels: Advantages, Challenges, and Applications

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(27)

Published: April 2, 2023

Abstract Organogels are an important class of gels, and comparable to hydrogels owing their properties as liquid‐infused soft materials. Despite the extensive choice liquid media compatible networks that can provide a broader range properties, relatively few studies reported in this area. This review presents applicability organogels concerning components, unique applications. Their distinctive features compared other gels discussed, including multi‐stimuli responses, affinity broad substances, thermal environmental stability, electronic ionic conductivity, actuation. The active role solvents is highlighted versatility organogel properties. To differentiate between these classified filled with different organic liquids, highly polar binary solvent systems. Most promising applications sophisticated multifunctional materials discussed light features.

Language: Английский

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Recent advances in 3D printing of tough hydrogels: A review

Composites Part B Engineering, Journal Year: 2022, Volume and Issue: 238, P. 109895 - 109895

Published: April 13, 2022

Language: Английский

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