Iron(III)-Based Triple Network High-Strength Low-Swelling Hydrogel

Abstract

In this study, a tough chitosan-gelatin-polyacrylamide-Fe³⁺ (CGPA-Fe³⁺) hydrogel with a triple-network structure is successfully synthesized using photoinitiated free-radical polymerization. The hydrogel is designed to achieve a high-strength, low-swelling material suitable for biomedical applications. Experimental results demonstrate that the CGPA-Fe³⁺ hydrogel exhibits excellent mechanical properties, with a compressive stress of 5.29 MPa and a compressive modulus of 1.27 MPa under 80% compressive strain. Furthermore, the CGPA-Fe³⁺ hydrogel shows outstanding fatigue resistance, retaining nearly 100% of its peak stress after 10 compression cycles. It also displays remarkable self-recovery capabilities, with an energy dissipation recovery rate exceeding 85% after a 60-s rest period. Regarding swelling behavior, the hydrogel demonstrates excellent stability, further highlighting its potential for structural biomedical applications. In summary, the CGPA-Fe³⁺ triple-network hydrogel represents a promising candidate for high-strength, low-swelling materials. This study provides a novel approach and strategy for designing advanced hydrogels with superior mechanical performance and stability.