Additively manufactured tannic acid-nanocellulose structures with superior mechanical, antioxidant, and antibacterial properties

초록

Nanocellulose (NC), including cellulose nanofibers and nanocrystals, is a renewable, biodegradable material, but has weak antioxidant and antimicrobial properties. Here, this paper presents an extrusion-based 3D printing technique to print a concentrated (≥26 wt% solid content) NC paste by adding different concentrations (0.75, 1.5, and 2.25 wt%) of tannic acid (TA). The 3D-printed structures were dried in cleanroom conditions (relative humidity: 45 % and temperature: 25 °C), followed by post-curing. The 3D-printed TA-NC structures demonstrate a maximum bending strength of 138.0 ± 2.3 MPa (246.5 % increase compared with NC), a maximum flexural modulus of 15.0 ± 0.9 GPa (205.39 % increase compared with NC), a maximum compressive strength of 31.9 ± 1.5 MPa, and a maximum compressive modulus of 128.3 ± 12.2 MPa. Furthermore, they show excellent antioxidant activity (94.5 %) and antibacterial properties. This preliminary study demonstrates that extrusion-based 3D printing enhances the mechanical, antioxidant, and activity against Escherichia coli of TA–NC scaffolds, showing the possibility for external biomedical fixation applications. © 2025 Elsevier B.V.

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