Research review May 2018: new topics from the world of cellulose fibrils
Ole Martin Kristiansen | May 29, 2018
Ever heard about bouligand structures or tunicates? And how are these topics relating to nanocellulose? This week’s research review is giving you a summary of some really exciting news relating to strength performance from nanocellulose (nanocrystalline cellulose). In addition, we are bringing you news on nanocellulose as an art-preservation aid. Spend 4 minutes and read through some really interesting updates.
Can the mix of aquaculture and wood sources give improved composites?
Heard about the bouligand structure before? I had not, so I needed to do some research. Bouligand structure is “a layered and rotated microstructure resembling plywood, which is frequently found in naturally designed materials”. In plane words, it’s a twisted structure looking like plywood. And what does it bring? Well, it allows the material to adapt to the tensile loading, meaning that if you twist and turn it, it will distribute the forces in the material in a way that distributes them more effectively, rather than create cracks in an early phase. This is a way of describing a somewhat elastic material.
So, this one is interesting to me. Why you say? Some of the scientists at the National institute of Standards and Technology (NIST), have discovered that if they combine something called tunicates, and nanocrystalline cellulose (NCC), they get to a material which shows significant strength and elastic properties. They have mixed long and short fiber structures (long from the tunicates, and short from the NCC. They added up to 30% tunicates to the NCC and got to a 15-20 times tougher material(!). They also found that 30% was the limit, after this the toughness was reduced.
Where would one need composites that are strong and flexible? NIST points at aerospace composites and other high-performance composites where distribution of forces is very important.
An article in ACS Applied Nano Materials, researchers at the Chalmers university in Sweden investigated how cellulose fibrils (CF) and silicananoparticles (SNP) together could improve the art preservation of paintings. The article stresses that the major weakness in the art itself and detoriation over time is relating to the canvas used (which is typically made of cellulose fibers). They found that the SNP and CF acted in two different ways: the SNP penetrated the canvas and strengthened the individual fibers of the canvas, while the CF increased the surface toughness of the canvas as well as increasing its flexibility. Thus, this method was concluded to be a valid alternative to the current processes mainly used.
Ole Martin Kristiansen
Ole Martin is the Marketing Manager of Exilva in Borregaard. He holds a bachelor's degree in Media Management and has been with the company since 2017.