A Self‐Healing Dielectric Supramolecular Elastomer Functionalized with Aniline Tetramer

Abstract

A new design strategy to produce a supramolecular elastomer with self‐healing and dielectric properties by synthesizing an aniline tetramer (AT)‐functionalized supramolecular elastomer (SE‐AT) is demonstrated. The termination of AT in the supramolecular system not only shortens linear amide molecular chain to decrease glass transition temperature but also destroys the crystallization to achieve amorphous structure. The SE‐AT provides two kinds of noncovalent bonding including π–π stacking and the hydrogen bond, which makes the material more easily healed. The SE‐AT20% can heal mechanical properties within 24 h at room temperature without any external stimulus. The dielectric constant shows a continuous increase overall with increasing AT content. The material exhibits good electro‐mechanical properties, which is attributed to a simultaneous increase in dielectric constant and decrease in modulus. The maximum actuated strain significantly increases with the increasing AT content and the SE‐AT20% reaches 10% at 1 V µm−1. Moreover, SE‐AT exhibits the ability to regain actuated strain on the location of the mechanical damage after self‐healing.

Self-Healing of Materials under High Electrical Stress

“…Li et al 69 developed highly stretchable and autonomous self-healing materials using dynamic metal-ligand interactions. When a square-wave field of >17.2 MV m À1 was applied to the self-healing dielectric elastomer actuator after the introduction of mechanical damage, an area expansion of 3.6% was achieved, thereby indicating the excellent self-healing ability of the material at temperatures as low as À20 C. Liu et al 71 produced a self-healing dielectric supramolecular elastomer functionalized with aniline tetramer. The maximum actuation strain increased with an increase of aniline tetramer content, for example, a healed elastomer with 15% aniline tetramer showed an area expansion of 4% at 9 MV m À1 at the location of the mechanical damage.…”

Electrical and Mechanical Self‐Healing in High‐Performance Dielectric Elastomer Actuator Materials

“…[15] Liu et al reported a supramolecular elastomer that self-healed with & ~ 64 -4126, Y ~ 12 -400 kPa, and relatively low E b ~ 1.1 -9.5 kV mm -1 and demonstrated self-healing of mechanical damage in a dielectric elastomer, however, the high dielectric loss (tan d) is a potential concern for device performance. [16] Finally, self-healing of mechanical and electrical damage was reported in hydrogen-bonded supramolecular polymer nanocomposites based on surface functionalised boron nitride nanosheets. [17] .…”

Self-Healing Dielectric Elastomers for Damage-Tolerant Actuation and Energy Harvesting

“…The use of dynamic covalent bonds, such as Diels–Alder interactions, − disulphide, − or imine bonds, , allows the polymer chains to break and reform during thermal treatment. The introduction of supramolecular interactions, such as hydrogen bonding, − ionic bonding, π–π stacking, , or metal–ligand coordination, , into polymer structures can also assist the self-healing process because of the reversible and reformative nature of the noncovalent interactions. The bond strength of the noncovalent interactions affects the self-healing dynamics and kinetics, where supramolecular interactions are also affected by phase segregation, crystallization, and chain entanglement .…”