Recent progress on segregated polymer composites for functional applications

Polymer composites embedded with functional particles (e.g., conductive, thermally conductive, or magnetic fillers) integrate the processability of polymers with the tailored functionalities of these additives. However, conventional composites often necessitate excessively high loadings to establish percolation networks, leading to challenges such as increased costs, diminished mechanical performance, and compromised processability. Segregated structures-where particles are selectively localized at polymer domain interfaces-significantly enhance filler utilization efficiency, outperforming traditional composites with uniformly dispersed particles. Since our group’s seminal 2014 review on electrically conductive segregated polymer composites, extensive advancements have been achieved across diverse applications, including electromagnetic interference shielding, thermal management, and gas barriers. Innovative processing strategies have also been tailored to accommodate various polymer matrices. Despite these breakthroughs, critical gaps persist in understanding the mechanistic interplay and scalable fabrication of multifunctional segregated systems. This review systematically synthesizes the progress in segregated polymer composites over the past decade, emphasizing novel fabrication techniques, matrix-dependent design principles, and emerging functional applications. We critically analyze persistent challenges-such as interfacial control, and scalability-alongside recent solutions and evolving research trends. By elucidating structure–property correlations and offering actionable design guidelines, this work aims to drive the broader adoption of segregated structures and accelerate the development of next-generation high-performance functional materials.