materialsscienceandengineering:

Crab-shell and seaweed compounds spin into yarns for sustainable and functional materials

Researchers from Aalto University, the University of São Paulo and the University of British Columbia have found a way to make a new kind of fibre from a combination of chitin nanoparticles, extracted from residual blue crab shells and alginate, a compound found in seaweed. This new bio-based material is sturdy and has antimicrobial properties.

The team studied how differences in the concentration of each component, the size of the nanoparticles, and other variables affect the mechanical properties and spinnability of the final thread. With this information, the researchers were able to produce strong, flexible threads continuously.

Professor Orlando Rojas from the Biobased Colloids and Materials (BiCMat) team at Aalto University, says that the researchers wanted to make a fibre that combined the properties of chitin – known for its antimicrobial properties – and seaweed alginate, which forms strong gels, ‘The designed material, took advantage of the strong interaction between the components, which are oppositely charged. We found that when a solution of alginate contacts a suspension of chitin nanofibers, the alginate wraps around the chitin nanoparticles, forming fibrils that align in parallel as the thread is drawn upward’.

Alginate dissolves readily in water. Brown algae have alginic acid in its cell walls, which can be converted to sodium alginate. The blue crab shells were ground and purified; then the material was partially deacetylated using simple procedures.

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