Suppression of Delayed Fracture in Polyampholyte Hydrogels via Microphase-Separated Structure

作者：Siqi Huang (2558686), Kaining He, Yike Li (1529680), Kunpeng Cui · 发表于：Figshare · 年份：2026 · DOI：10.1021/acs.macromol.6c00674.s001 · 研究领域：Hydrogels: synthesis, properties, applications、Calcium Carbonate Crystallization and Inhibition、Advanced Materials and Mechanics

Polyampholyte (PA) hydrogels, distinguished by their unique microphase-separated structures, exhibit exceptional toughness and self-healing capabilities, making them promising candidates for load-bearing soft materials. Investigating the delayed fracture behavior of these materials under stress relaxation, along with their underlying microscopic failure mechanisms, is critical for predicting their long-term reliability. This study aims to elucidate the pivotal role of microphase-separated structures in governing the delayed fracture mechanism of PA hydrogels. By tuning the concentration of the chemical cross-linker, we synthesized hydrogels possessing either microphase-separated or single-phase structures and systematically compared their stress-relaxation responses. Single-phase hydrogels exhibit typical delayed fracture behavior during stress relaxation, with the failure time decreasing rapidly as the imposed relaxation strain approaches the tensile fracture strain. Within the present experimental window, the delayed fracture lifetime shows an empirical exponential dependence on the strain distance (ε f – ε r ), where ε r is the imposed relaxation strain and ε f is the fracture strain during uniaxial stretching. In contrast, microphase-separated hydrogels do not exhibit delayed fracture even when the applied strain approaches the fracture strain ε f . This remarkable resistance arises from their multiscale energy-dissipation mechanisms, including reversible ionic bond di...