Cation–π interactions in polymer science: from fundamental insights to material applications

This review comprehensively assesses recent advancements in the utilization of cation–π interactions in high-performance polymers, a unique form of point-to-face non-covalent bonding with significant implications in both biological systems and materials science. We begin by exploring the fundamental properties of cation–π interactions, including their nature, influencing factors, and various classifications. The review then delves into specific types of high-performance polymer materials, such as films, porous materials, hydrogels, composites, and storage materials, each illustrating how cation–π interactions influence their structure and properties. Particular emphasis is placed on the challenges of precise molecular design, stability under diverse conditions, multifunctionality, and managing competing interactions. Through selected examples, we highlight strategies to regulate and enhance these interactions, offering insights into the future trajectories of research in this rapidly evolving field.