A Bio‐Based Supramolecular Adhesive: Ultra‐High Adhesion Strengths at both Ambient and Cryogenic Temperatures and Excellent Multi‐Reusability

Abstract

Developing high-performance and reusable adhesives from renewable feedstocks is of significance to sustainable development, yet it still remains a formidable task. Herein, castor oil, melevodopa, and iron ions are used as building blocks to construct a novel bio-based supramolecular adhesive (BSA) with outstanding adhesion performances. It is prepared through partial coordination between melevodopa functionalized castor oil and Fe 3+ ions. Noncovalent interactions between adherends and the catechol unit from melevodopa contribute to reinforcing adhesion, and the metal-ligand coordination between catechol and Fe 3+ ions is utilized to strengthen cohesion. By combining strong adhesion and tough cohesion, the prepared BSA achieves an adhesion strength of 14.6 MPa at ambient temperature, a record-high value among reported bio-based adhesives as well as supramolecular adhesives to the best of knowledge. It also outperforms those adhesives at cryogenic temperature, realizing another record-high adhesion strength of 9.5 MPa at −196 °C. In addition, the BSA displays excellent multi-reusability with more than 87% of the original adhesion strength remaining even after reuse for ten times. It is highly anticipated that this line of research will provide a new insight into designing bio-based adhesives with outstanding adhesion performances and excellent multi-reusability.

High‐Performance Supramolecular Adhesives

“…To figure out this relationship and construct supramolecular adhesives with high bonding strengths, Sun, Xu, and coworkers developed an ultra strong bio-based supramolecular adhesive (BSA) recently. [31] As shown in Figure 4a, the BSA was prepared through partial coordination between melevodopa functionalized castor oil and iron ions (Fe 3+ ). The metal-ligand coordination between catechol and Fe 3+ contributed to improving mechanical properties.…”

“…Reproduced with permission under the terms of the CC-BY license. [31] Copyright 2022, the Authors. Published by Wiley-VCH GmbH.…”

“…In recent years, by combining well-developed noncovalent interactions with rational design strategies, strong and functional supramolecular adhesives have been fabricated. [24][25][26][27][28][29][30][31] In this perspective, as shown in Scheme 1, we will discuss lately developed high-performance supramolecular adhesives and their design strategies. At first, supramolecular adhesives with high bonding strengths are focused.…”

“…By improving mechanical properties and enhancing interfacial interactions, the adhesion strength of supramolecular adhesives has been increased substantially. [24,27,29,31] Second, we will concentrate on how to construct underwater and conductive supramolecular adhesives. By absorbing or repelling the hydration layer on adherend surfaces, supramolecular adhesives can be endowed with the functionality of joining substrates together in water.…”

“…b) The Young's modulus and adhesion force,and c) the adhesion strength of BSA with the increased content of iron ions. Reproduced with permission under the terms of the CC-BY license [31]. Copyright 2022, the Authors.…”