On the role of water in regulating the mechanics of collagen fibers

Abstract

The mechanical properties of collagen fiber–based materials have garnered considerable attention owing to their application in various hydration environments. Herein, we conducted a comprehensive investigation on the mediatory role of water in the mechanical properties and structure of collagen fibers. Lower hydration levels are conducive to the mechanical strength, particularly the tensile and tear properties, and reduce the softness of collagen fibers as well as the D-period and the lateral spacing between collagen molecules. Atomic force microscopy measurements indicate that lower hydration levels also enhance the roughness, adhesion force and lateral forces between collagen fibers. Theoretical calculations further reveal that the hydration level regulates weaker components of water-mediated interactions, such as electrostatic and van der Waals forces, which dominate the resistance against mechanical shock. Our findings provide valuable insights into the role of water in regulating the mechanical behaviour of collagen fibers, thereby contributing to the development of novel high-performance collagen fiber materials.