Tough Supramolecular Polymer Networks with Extreme Stretchability and Fast Room‐Temperature Self‐Healing

Abstract

Recent progress on highly tough and stretchable polymer networks has highlighted the potential of wearable electronic devices and structural biomaterials such as cartilage. For some given applications, a combination of desirable mechanical properties including stiffness, strength, toughness, damping, fatigue resistance, and self-healing ability is required. However, integrating such a rigorous set of requirements imposes substantial complexity and difficulty in the design and fabrication of these polymer networks, and has rarely been realized. Here, we describe the construction of supramolecular polymer networks through an in situ copolymerization of acrylamide and functional monomers, which are dynamically complexed with the host molecule cucurbit[8]uril (CB[8]). High molecular weight, thus sufficient chain entanglement, combined with a small-amount dynamic CB[8]-mediated non-covalent crosslinking (2.5 mol%), yields extremely stretchable and tough supramolecular polymer networks, exhibiting remarkable self-healing capability at room temperature. These supramolecular polymer networks can be stretched more than 100× their original length and are able to lift objects 2000× their weight. The reversible association/dissociation of the host-guest complexes bestows the networks with remarkable energy dissipation capability, but also facile complete self-healing at room temperature. In addition to their outstanding mechanical properties, the networks are ionically conductive and transparent. The CB[8]-based supramolecular networks are synthetically accessible in large scale and exhibit outstanding mechanical properties. They could readily lead to the promising use as wearable and self-healable electronic devices, sensors and structural biomaterials.

Applications of Cucurbit[n]urils (n=7 or 8) in Pharmaceutical Sciences and Complexation of Biomolecules

“…[4] These properties have attracted much attention from scientists. [10] On the other hand, due to its modest water-solubility and a larger cavity that can often accommodate two small molecules simultaneously, [3] CB [8] has been widely used in polymer/material sciences [11] and biomedical sciences. [5] Upon encapsulation by CB [7], a variety of drug molecules have exhibited enhanced bioavailability, [7] improved water solubility, [8] modulated efficacy [9] and reduced toxicity.…”

Dynamic Interfacial Adhesion through Cucurbit[n]uril Molecular Recognition

“…Movie 3s hows the peeling process of Benz@HBP-CB [8]@Benz. [17][18][19][29][30][31] Benz@HBP-CB [8]@Benz lap-joints were subjected to peeling until failure, they were then re-bonded and subjected to another peeling measurement. On account of its dynamic nature,CB[8] molecular recognition imparts av ariety of supramolecular self-assemblies with astounding reversible and self-healing characteristics.…”

Patterned Arrays of Supramolecular Microcapsules

“…[22][23][24][25][26] In this study we exploit supramolecular building units to construct patterned hydrogel microcapsules on solid substrates for cargo delivery and chemical sensing. [22,29,33,34] [22,[27][28][29] In our previous report, supramolecular microcapsules can be readily fabricated through a one-step microfluidic approach.…”