Interfacial interaction-driven comparison of phase-transition and phase-change nanocomposite hydrogels for multifunctional energy-therapeutic platforms

Abstract

A new class of soft materials known as phase-transition and phase-change hydrogels (PTHs and PCHs, respectively) may undergo reversible changes in volume or structure in response to external stimuli, including heat, light, pH, or electromagnetic fields. For sophisticated healthcare, energy, and smart device applications, their chemical adaptability and adjustable mechanical properties have attracted significant attention. The basic ideas that determine hydrogel responsiveness and multifunctionality are introduced at the outset of this review, followed by classifications and design guidelines. After that, this review delves into synthesis techniques for customizing PTHs and PCHs, with a focus on using nanoparticles as reinforcing agents to improve multifunctionality, strength, and responsiveness. To demonstrate how nanoscale interactions regulate mechanical reinforcement, energy dissipation, phase-change kinetics, the molecular processes and structure–property correlations driving phase transitions are examined. Energy technologies (thermal management, storage, and wearable electronics), smart devices (actuators, sensors, and bioelectronics), and therapeutic systems (drug delivery, tissue engineering, and photothermal treatment) are among the recent advancements in multifunctional applications that are reviewed. Finally, this study addresses key challenges such as biocompatibility, long-term stability, and scalability of production, which offers future perspectives for flexible, sustainable, and multipurpose soft materials.