Noncovalent Aggregation for Diverse Properties in Hydrogels: A Comprehensive Review

The rapid expansion of hydrogel research over recent decades has bridged fundamental chemistry and physics with advanced materials science applications. This field necessitates comprehensive and in-depth review and discussion of the diverse and rapidly expanding body of research, thereby providing a cohesive understanding that can drive future innovations and applications. This review delves into the role of noncovalent interactions in hydrogel aggregation, a critical mechanism for creating desired microstructures that enhance material properties. Inspired by natural molecular architecture, this paper explores how synthetic hydrogels exploit hydrogen bonds, hydrophobic interactions, and other noncovalent forces to create robust, multifunctional, and water-rich networks. We further discuss methods to induce these interactions and the unique properties resulting from the formed structures. With these methods, we provide insights into the art of manipulating aggregated structures within hydrogels to develop adaptable, tunable materials for a broad range of applications, including bioengineering, robotics and soft electronics, highlighting their significant practical value across interdisciplinary fields.