Confined entanglement networks coordinate hierarchical energy dissipation in super-tough hydrogels

Abstract

Weak interfacial interaction and poor dispersion of conventional nanofillers within nanocomposite hydrogels often induce stress concentration, creating a dilemma between strength and toughness. Herein, a polyacrylamide–carbon aggregate (PAM–CA) hydrogel featuring a constrained entanglement network was successfully constructed by incorporating chlorophyll-derived carbon aggregates (CAs). Mechanistic investigations reveal that the exceptional mechanical properties originate from a hierarchical energy dissipation process: (i) the unfolding and stretching of entangled polymer chains, (ii) the reversible detachment of chains from CAs (rupture of sacrificial hydrogen bonds), and (iii) supporting structure integrity by the PAM network. Consequently, compared with the neat PAM hydrogel, the PAM–CA hydrogel exhibits a tensile strength of 1039 kPa (∼12-fold increase), an elongation at break of 2496% (∼3.7-fold), and a remarkable toughness of 10.1 MJ m⁻³ (∼35-fold). Furthermore, the PAM–CA hydrogel possesses superior adhesiveness, compressibility, and electrical conductivity. This study provides a facile fabrication strategy for the design of high-performance, multifunctional hydrogels.