Material Adhesion through Direct Covalent Bond Formation Assisted by Noncovalent Interactions

Effective, quick, and stable adhesion systems are expected in many fields. Direct covalent bond formation has the potential to realize the adhesion between materials. However, adhering materials without conventional glues, which show anchoring effects to mechanically support the surface of the adherent, is generally difficult. Here, noncovalent interactions were employed in combination with a direct covalent bond formation to achieve effective adhesion between materials. Adhesion via hostguest interactions and amide bond formation was designed to adhere objects such as polymeric materials and glass. Host-guest interactions and amide bond formation cooperatively led to strong adhesion between these materials. The rupture strength between the test pieces increased with increasing molar contents of the host and guest units. Further investigation, including competitive guest tests, revealed that the host-guest interactions support amide bond formation to achieve effective direct bonding between the adherents.