Graphene-based spine in seaweed gel offers enables industrial applications

Seaweed has for millennia been a rich source of materials useful for humanity. It was arguably the basis of the very first chemical industries, yielding iodine for medical uses in prehistory; its use in agriculture as a fertiliser has often underpinned the economies of island nations with scarce cultivatable land; and, of course, many species are themselves edible. In more recent years, seaweeds and other marine plants have been investigated by industrial chemists as sources of oil is and other materials. Alginate, a natural hydrogel, has found applications in the medical sector, but because they tend to be mechanically fragile and unstable in certain solutions, their uses are somewhat limited.

Engineers at Brown University in Rhode Island have now developed a way of reinforcing alginate by incorporating the atomically-thick layered material graphene oxide into its structure. This produces a material that can be 3D printed into structures that are stiffer and more fracture resistant than alginate alone. Furthermore, changes in the chemical environment can make the composite even stiffer or softer, allowing the structures to respond their surroundings in real time. Despite this change in behaviour, the composite retains some of the useful properties of alginate.