Quadruple Hydrogen-Bonding Cross-Linked Networks Empowering Supramolecular Ionic Pressure-Sensitive Adhesives with Robustness and Response

A robust and highly responsive pressure-sensitive adhesive (PSA) holds significant importance in interface interaction technology, requiring specific attributes such as a low modulus for surface adhesion, high strength to withstand stress, and responsiveness to external stimuli. However, achieving these requirements is often challenging due to structural limitations. In this study, a series of supramolecular ionogels with quadruple hydrogen bonding cross-linked networks and mobile ions were developed to decouple the modulus-strength relationship, thereby enhancing sensing performance. The quadruple hydrogen bonds cross-linked supramolecular networks exhibit good strength even with an increased ionic liquid content of up to 30 wt %. As a result, impressive lap-shear strengths of 2165.1 kPa on aluminum and tacking bond strengths of 1842.6 kPa on glass were attained, surpassing most of the literature-reported values. Additionally, the movement or orientation of ions under voltage application led to a 69.5% enhancement in the bonded strength. Moreover, the PSA demonstrated stress sensing capabilities, achieving a sensitivity of 32.2 MPa –1 in lap-shear applications and 9.5 MPa –1 in compression scenarios.