1College of Materials Science and Engineering, Hunan University, China
Materialization of ionic liquids (ILs) is truly a novel, promising research direction for IL research. The obtained materials combine the advantageous characteristics of ILs with the original properties of the functional groups or materials, and in some cases exhibit unexpected functions resulting from synergistic interactions between the two components. In this study, we demonstrated that a range of small-molecule and polymeric ILs could be designed as novel adhesive materials, with the incorporation of bulky, asymmetric ionic groups playing a crucial role in achieving high adhesion. Specifically, the introduction of these groups prevented the formation of an ordered stacking structure of high-density and multiple hydrogen bonds within the adhesive materials, thus lowering the glass transition temperature to facilitate adhesion, while also enhancing the cohesive energy of the adhesive materials through strong electrostatic interactions. In addition, the adhesive ILs formed numerous free hydrogen bond donors and acceptors at the adhesive interface, further promoting adhesion. These IL-based adhesives exhibited exceptional adhesion properties on various substrates, exceeding the performance of most commercial adhesives. Moreover, the compatibility of ILs with inorganic/organic materials allows for the development of multifunctional adhesives.