We made a paper from nanocellulose, but its very brittle. How could we alleviate this problem?

Brittleness in nanocellulose paper can be a common issue due to the inherent properties of nanocellulose fibers and the way they are processed. Here are several strategies you can consider to alleviate brittleness and improve the mechanical properties of your nanocellulose paper: 1. **Additives:** - **Plasticizers:** Incorporate plasticizers such as glycerol, sorbitol, or polyethylene glycol (PEG) to increase flexibility and reduce brittleness. - **Polymers:** Blend with flexible polymers (e.g., polyvinyl alcohol (PVA), polylactic acid (PLA)) to improve mechanical performance. - **Natural Additives:** Consider using natural additives such as chitosan or gelatin, which can improve flexibility. 2. **Filler Materials:** - Incorporate fillers (e.g., talc, starch, or clay) that can enhance flexibility and tensile strength while reducing brittleness. 3. **Fiber Orientation:** - Optimize the processing conditions to improve fiber orientation in the paper, which could enhance the mechanical properties. 4. **Multilayer Structures:** - Create a layered paper structure where layers have different compositions or orientations, providing better overall mechanical properties. 5. **Composite Materials:** - Develop nanocellulose-based composites with other materials (e.g., natural fibers or synthetic fibers) to balance rigidity and flexibility. 6. **Crosslinking Agents:** - Use crosslinking agents to enhance bonding between fibers. This increases the overall cohesion of the paper structure, improving toughness. 7. **Drying Conditions:** - Adjust drying conditions (temperature, humidity) during production to ensure the paper retains some moisture content, potentially improving flexibility. 8. **Mechanical Treatments:** - Apply mechanical treatments such as beating or refining processes to alter the fiber structure, potentially improving flexibility and reducing brittleness. 9. **Addition of Nanomaterials:** - Introduce other nanomaterials such as graphene or carbon nanotubes to enhance mechanical properties without compromising flexibility. 10. **Surface Treatment:** - Use surface treatments or coatings to improve flexibility and toughness. For example, adding a thin polyvinyl acetate (PVAc) layer may help. By combining some of these strategies, you should be able to improve the mechanical properties of your nanocellulose paper and reduce its brittleness effectively. Consider evaluating different combinations to find the optimal formulation for your specific application.