Nanomaterials, such as nanoclays, carbon nanotubes and graphene, have been extensively investigated in terms of their ability to bring additional functionality to composites. Nano-scale particles typically have a very high surface area to volume ratio, meaning that the addition of relatively small amounts to a composite can bring significant improvements in performance.
At NetComposites, we have just finished a three year collaborative programme looking at a particular family of nanomaterials known as “crystalline nano cellulose (CNC)”. These are highly crystalline nanoparticles that can be extracted from sustainable sources such as paper mill or forestry waste. A single CNC fibre has a stiffness of around 150 GPa and a strength of 10 GPa, meaning that they have a high potential as building blocks for 100% bio-based structural materials.
Specifically, our team has examined the use of CNC as the basis for producing lightweight core materials for composite sandwich structures. Our partners from Melodea and the Hebrew University of Jerusalem have developed a technology for extracting CNC from waste streams of cellulose and then self-assembling the resulting nanoparticles into three-dimensional cellular structures. At NetComposites we have examined how these biofoams can be further stiffened and strengthened by resin infusion and subsequently incorporated within sandwich composites. By combining these CNC-based foam cores with our flax fibre Ecopreg materials, we’ve been able to achieve truly 100% bio-based structural composites.
You can find out more about this work at ncc-foam.eu
Joe Carruthers is the Managing Director of NetComposites