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nanotimes

News in Brief

10-03 :: March 2010

Materials //

Biomimetic Composites with Superior Material Properties

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esearchers at the Helsinki University of Techno- logy/Aalto University School of Science and

Technology, Finland, describe a process for advan- ced large-scale biomimetic materials in Nano Let-

ters. The new invention is based on deep understan- ding of self-assembly processes in material science, say PhD Andreas Walther and Academy professor Olli Ikkala who lead the project. “We have used self-assemblies and hierarchies already long in other types of materials to achieve functional properties. A good example of self-assembly is given by proteins whose chains contain in a delicate manner the in- formation how to assemble as functional structures,” they add.

They introduce a surprisingly simple and rapid methodology for large-area, lightweight, and thick nacre-mimetic films and laminates with superior material properties.

Nanoclay sheets with soft polymer coatings are used as ideal building blocks with intrinsic hard/soft character. They are forced to rapidly self-assemble into aligned nacre-mimetic films via paper-making, doctor-blading or simple painting, giving rise to strong and thick films with tensile modulus of 45 GPa and strength of 250 MPa.

The coatings that Helsinki researchers developed are strong and lightweight. However, they need to be

tougher for use as structural materials such as steel. The material properties are similar to those of fiber- glass, according to Andreas Walther. The researcher think that the results might be a breakthrough for

biomimetic materials.

The concepts are environmentally friendly, energy- efficient, and economic and are ready for scale-up via continuous roll-to-roll processes.

The researchers will work with the Finnish paper company UPM to commercialize the material. A patent for this and the like processes is pending.

Andreas Walther, Ingela Bjurhager, Jani-Markus Malho, Jaakko Pere, Janne Ruokolainen, Lars A. Berglund and Olli Ikkala: Large-Area, Lightweight and Thick Biomimetic Composites with Superior Material Properties via Fast, Eco- nomic, and Green Pathways, In: Nano Letters ASAP, March 10, 2010, DOI:10.1021/nl1003224: http://dx.doi.org/10.1021/nl1003224

http://tfy.tkk.fi/personnel/official.php?id=388 http://www.upm.com