Renewable Adhesive Provides Effective Bonding Underwater

Renewable Adhesive Provides Effective Bonding Underwater The National Institute for Materials Science (NIMS) has developed a renewable adhesive that enables repeated bonding and debonding cycles and can restore both the substrate and adhesive to their original state when needed. As awareness grows regarding the need to balance environmental concerns with economic growth, demand has emerged for technologies that enable the disassembly and recovery of multi-component molded products. In this context, attention is turning toward a new adhesion method that provides sufficient bonding during use while allowing easy release once the purpose is fulfilled. The challenge lies in combining seemingly contradictory elements such as strong adhesion and easy debonding. Furthermore, even when separation was achieved, problems such as adhesive residue on the substrate or substrate damage have hindered material recovery. In this study, the research team focused on ferulic acid, which can reverse cross-linking and bond-breaking reactions through irradiation with ultraviolet (UV) light at different wavelengths. This research was published in Advanced Functional Materials journal. In the study, a polymer containing ferulic acid was applied to a substrate and formed a cross-linked film that became insoluble when exposed to 365 nm UV light. This film shows no adhesion when stored at room temperature, but can be repeatedly bonded and debonded when heated. Additionally, when the film was exposed to 254 nm UV light at the end of its service life, the cross-linked portions broke apart and reverted to their original state prior to application, enabling both the adhesive and substrate to be recovered and reused. Furthermore, the catechol groups found in the chemical structure of ferulic acid are commonly present in adhesive compounds secreted by adhesive organisms such as mussels. This adhesive has demonstrated strong bonding and recyclability even on substrates and under environmental conditions that are challenging for conventional adhesives such as fluoropolymers and underwater adhesion. In future research, the team will investigate the effectiveness of this adhesive in the repair of various technologies including electronic devices, transportation equipment, medical equipment, and physical infrastructure, with the aim of contributing to a circular economy. The project was conducted by a research team led by Masanobu Naito (Director of Macromolecules Division, Macromolecules and Biomaterials Research Center (RCMB), NIMS) and Siqian Wang (Postdoctoral Researcher, RCMB, NIMS). Academic Reference: Siqian Wang et al, Bio-Inspired Adhesive with Reset-On Demand, Reuse-Many (RORM) Modes, Advanced Functional Materials (2023). DOI: 10.1002/adfm.202215064   Source