Wonder what would happen if this research team hooked up with these guys: http://tinyurl.com/slime-mold-network
- Sid. On 1/26/10, Udhay Shankar N <[email protected]> wrote: > http://www.newscientist.com/article/mg20527445.600-smart-mud-could-be-the-new-plastic.html > > Smart mud could be the new plastic > > * 20 January 2010 by Colin Barras > > Could a mixture of water and clay replace plastics? The desire to wean > the world off oil has sparked all manner of research into novel > transportation fuels, but manufacturing plastics uses large amounts of > oil too. Researchers at the University of Tokyo, Japan, think their > material could be up to the task. > > Takuzo Aida and his team mixed a few grams of clay with 100 grams of > water in the presence of tiny quantities of a thickening agent called > sodium polyacrylate and an organic "molecular glue". The thickening > agent teases apart the clay into thin sheets, increasing its surface > area and allowing the glue to get a better hold on it. > > This means that, while the mixture is almost 98 per cent water, it forms > a transparent and elastic hydrogel with sufficient mechanical strength > to make a 3.5-centimetre-wide self-standing bridge. > > Self-repairing hydrogel > > The strength of the material depends on the sum of the forces acting > between the molecules in the clay nanosheets and the glue, says Aida. > These so-called supramolecular forces, such as hydrogen bonds, also help > to trap water molecules between the clay sheets. > > Some other hydrogels rely on covalent chemical bonds rather than > supramolecular forces for their strength. One disadvantage of this is > that when the covalent bonds break, the material irreversibly loses its > strength, says Aida. Supramolecular forces, on the other hand, can > easily reform, so if the material fails under stress it can quickly > regain its strength. > > The gel takes just 3 minutes to form, and making it requires no > understanding of the chemical process involved, Aida says, – a fact that > impresses Craig Hawker at the University of California in Santa Barbara, > who was not involved with the study. "One of the primary breakthroughs > is the overall simplicity of the procedure coupled with the exceptional > physical properties of the final assemblies," he says. > New class of materials > > "Toughness, self-healing and robustness are just some of the initial > physical properties that will be found for this new class of materials," > Hawker says. "I predict that this approach will lead to the design of > even more impressive materials in the near future." > > Polymer scientist Jian Ping Gong at Hokkaido University in Sapporo, > Japan, says the work is "beautiful" but points out that the material's > mechanical strength falls short of what is possible for plastics and > chemically cross-linked gels. > > Aida says that strengthening the material is as simple as increasing the > quantities of clay, sodium polyacrylate and glue, provided transparency > is not important. > > Journal reference: Nature, DOI: 10.1038/nature08693. > > > -- > ((Udhay Shankar N)) ((udhay @ pobox.com)) ((www.digeratus.com)) > >
