Anisotropic wood-hydrogel composites: Extending mechanical properties of wood towards soft materials’ applications
Sophie Marie Koch, Christian Goldhahn, Florence J. Müller, Wenqing Yan, Christine Pilz‐Allen, Cécile M. Bidan, Beatrice Ciabattoni, Laura Stricker, Peter Fratzl, Tobias Keplinger, Ingo Burgert
Abstract
Delignified wood (DW) offers a versatile platform for the manufacturing of composites, with material properties ranging from stiff to soft and flexible by preserving the preferential fiber directionality of natural wood through a structure-retaining production process. This study presents a facile method for fabricating anisotropic and mechanically tunable DW-hydrogel composites. These composites were produced by infiltrating delignified spruce wood with an aqueous gelatin solution followed by chemical crosslinking. The mechanical properties could be modulated across a broad strength and stiffness range (1.2–18.3 MPa and 170–1455 MPa, respectively) by varying the crosslinking time. The diffusion-led crosslinking further allowed to manufacture mechanically graded structures. The resulting uniaxial, tubular structure of the anisotropic DW-hydrogel composite enabled the alignment of murine fibroblasts in vitro, which could be utilized in future studies on potential applications in tissue engineering.