Sepiolite-based PDA-PAM hydrogels with enhanced interfacial adhesion capability

Document Type

Article

Publication Date

2-1-2025

Abstract

Elastic and dense connective tissues exhibit exceptional tensile strength and fatigue resistance, enabling them to withstand continuous stretching and cyclic loading. The endeavor to replicate these remarkable mechanical properties in artificial bionic robots or engineered tissues is still a challenge. Our study reveals that the toughness of the body's elastic connective tissues is due to the orderly arrangement of collagen fibers. These fibers, 20 to 100 nanometers in diameter, act as a crucial buffer, reducing tension and fatigue impact. Inspired by that, we design and fabricate a sepiolite-based polydopamine-acrylamide (S-PDA-PAM) hydrogel, which mimics the structure of human tissue. The results demonstrate that, through mechanical training, the sepiolite composite hydrogel exhibits a higher adhesive fatigue threshold. Aligned sepiolite nanofibers reinforce and prevent polymer chain debonding, functioning as a rigid matrix. This structural reinforcement greatly increases the energy barrier against fatigue crack propagation, significantly raising the interfacial fatigue threshold. This boost in fatigue resistance gives the composite material exceptional mechanical resilience, similar to natural tissues.

Publication Title

Surfaces and Interfaces

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