Nanomaterials

© Photo Fraunhofer SCAI

Nanoparticles feature exceptional material properties and thus provide a wide range of possible applications in various areas such as lightweight construction (composite materials, concrete), energy and environmental engineering (batteries, fuel cells, hydrogen storage), electronics (cooling, transistors, field emission display), medicine (sensor technology, drug-delivery) and also information and communication technology.

For instance, carbon nanotubes (CNTs) show outstanding mechanical, thermal and electrical properties. Hence they are already used in industrial applications for mechanical reinforcement and optimization of electrical conductivity of polymer composite materials. Besides carbon or boron-nitride based nanoparticles (Fullerene, CNTs, graphene, BN-NTs) also ceramic and metallic nanoparticles have already been synthesized with remarkable properties.

In the context of design and production of nanomaterials many questions and challenges emerge. To this end, the Department of Virtual Material Design of Fraunhofer SCAI provides several efficient software tools to tackle these problems.

Reinforced Nanomaterials

© Photo Fraunhofer SCAI

Due to their outstanding properties nanoparticels are widely used as fibers for modern high performance and lightweight nanocomposite materials. Carbon based nanoparticles for example are commonly applied to mechanically reinforce polymer composites. In particular CNTs are also used to increase the fracture toughness of ceramic nanocomposites as well as the tensile strength and ductility of metal-nanocomposites. Moreover, various types of nanoparticles are employed to obtain nanomaterials with different special effective properties.

Actual topics of research are on one hand the initial design and on the other hand the production process of the nanocomposites. Common challenges are the homogeneous dispersion of the fibers in the matrix and the optimal linkage of the fiber to the base material on the nanoscale. Additionally, in some cases the problem emerges that the structure of the nanoparticles is destroyed during the synthesis process of the composite matrix material. Then it is necessary to develop an alternative production process.

References

  1. C. Diedrich, D. Dijkstra, J. Hamaekers, B. Henninger, and M. Randrianarivony. A finite element study on the effect of curvature on the reinforcement of matrices by randomly distributed and curved nanotubes. Journal of Computational and Theoretical Nanoscience, 2014. accepted.
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  2. M. Griebel, J. Hamaekers, and F. Heber. A molecular dynamics study on the impact of defects and functionalization on the Young modulus of boron-nitride nanotubes. Computational Materials Science, 45(4):1097-1103, 2009.
    [ bib, note]
  3. M. Griebel and J. Hamaekers. Molecular dynamics simulations of boron-nitride nanotubes embedded in amorphous Si-B-N. Computational Materials Science, 39(3):502-517, 2007.
    [ bib, note]
  4. M. Griebel and J. Hamaekers. Molecular dynamics simulations of the mechanical properties of polyethylene-carbon nanotube composites. In M. Rieth and W. Schommers, editors, Handbook of Theoretical and Computational Nanotechnology, volume 9, chapter 8, pages 409-454. American Scientific Publishers, 2006.
    [ bib ]
  5. M. Griebel and J. Hamaekers. Molecular dynamics simulations of the elastic moduli of polymer-carbon nanotube composites. Computer Methods in Applied Mechanics and Engineering, 193(17-20):1773-1788, 2004.
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  6. S. J. V. Frankland, A. Caglar, D. W. Brenner, and M. Griebel. Molecular simulation of the influence of chemical cross-links on the shear strength of carbon nanotube - polymer interfaces. Journal of Physical Chemistry B, 106(12):3046-3048, 2002.
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Related Projects

Regarding research and development in this project, there is a close collaboration with the Institute for Numerical Simulation of the University of Bonn. Within this framework modules of the molecular dynamics software Tremolo-X have been successfully applied in the research project Multiscale QM/MM simulations of the growth process and the material properties of inorganic nanotubes and nanotube composites of the DFG priority program 1165 "Nanowires and Nanotubes: From Controlled Synthesis to Function" applied.