Designing New Materials with Nanostructures as Building Blocks
Vincent Meunier and Sefa Dag, CNMS
Jose Manuel Romo Herrera, Mauricio Terrones and Humberto Terrones,
Instituto Potosino de Investigacion Cientifica y Tecnologica, San Luis Potosi, Mexico
Novel and robust networks, tailored from nanostructures as building blocks, are the foundations for constructing nano- and microdevices. However, assembling nanostructures into ordered micronetworks remains a significant challenge in nanotechnology. The most suitable building blocks for assembling such networks are nanoparticle clusters, nanotubes and nanowires. Unfortunately, little is known about the different ways networks can be created and their physicochemical properties as a function of their architecture. It is expected that, when one-dimensional (1D) nanostructures are connected covalently, the resulting assemblies will possess mechanical, electronic, and porosity properties that are strikingly different from those of the isolated 1D blocks. Extensive theoretical studies by researchers from the CNMS (Vincent Meunier and Sefa Dag) and from the Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT, or Potosi Institute of Scientific and Technological Research) in San Luis Potosi, Mexico (Jose Manuel Romo Herrera, Mauricio Terrones and Humberto Terrones)  have shown that the properties of 2D and 3D networks built from 1D units are dictated by the specific architecture of these arrays. Specifically, they introduce the hierarchy concept, a practical way to design complex nanostructures from basis nano-building block. They also demonstrate that one can join nanotubes to make supernetworks that exhibit different properties compared to the individual building blocks (i.e. the nanotubes).
In addition to unique and unusual mechanical and electronic properties, the porosity of these systems makes them good candidates for exploring novel catalysts, sensors, filters, or molecular storage properties. The crystalline 2D and 3D networks are also expected to present unusual optical properties, in particular when the pore periodicity approaches the wavelength of different light sources, such as optical photonic crystals. The power of theoretical calculations at predicting novel materials with enhanced electronic and mechanical properties, using single atoms as building blocks, has been demonstrated repeatedly. A further step in this direction is to analyze the mechanical properties of 3D arrays built up from carbon nanotubes and study the influence of different framework architectures. Exploring these materials computationally will lead to the identification of promising candidates for synthesis.
This research was published in Nano Letters, and is featured on the March 1, 2007 issue cover.
 J. M. Romo-Herrera, M. Terrones, H. Terrones, S. Dag, and V. Meunier, “Covalent 2D and 3D Networks from 1D Nanostructures: Designing New Materials,” Nano Letters 7, 570–576 (2007).