Nanomaterials graphene

Y.H. Hu, H. Wang, B. Hu, Thinnest two-dimensional nanomaterials-graphene for solar energy. ChemSusChem 3, 782-796 (2010)... 

Rapid changes in material science such as nanomaterials, graphene, conductive polymers (both ionic and electronic), and ionic liquids will open battery designs to new formats such as thin printed and battery on board, nonreplaceableprimary batteries [7,8]. These trends, further coupled with the rise in popularity of low-power applications, may transition some of today s secondary electrochemistries into primary applications without the added cost of charge control systems required for secondary batteries. 

The nanomaterials chapter is also carefully surveyed, focusing on nomenclature, synthetic techniques, and applications taken from the latest scientific literature. The 2nd edition has been significantly updated to now include nanotoxicity, vapor-phase growth of 0-D nanostructures, and more details regarding synthetic techniques and mechanisms for solution-phase growth of various nanomaterials. Graphene, recognized by the 2010 Nobel Prize in Physics, is now also included in this edition. 

Graphene is a carbon material composed of carbon atoms in a single chip and is the thinnest and hardest nanomaterial on earth. The basic structural units of graphene are the most stable possible, benzene rings, and they form the current ideal of a two-dimensional nanomaterial.Graphene exhibits low resistivity and the most rapid electron transfer speed available. Therefore, it is expected to be utilized for the development of a new generation of thinner, more conductive electronic components or transistors. ... 

Fig. 3 Most studied nanomaterials in past two decades conductive polymer composites based on carbon nanomaterials (Graphene, SWCNT, and Fullerene from L-R Figs, taken from Refs. [85-87])...

In a similar vein of using nanomaterials, graphene has also been used as a support material in the form of a flexible graphene paper loaded with Au Pt core-shell nanoparticles the fabrication approach is shown in Fig. 16.11 where the hybrid electrode was fabricated through a modular approach in which the nanoparticle assembly was transferred onto graphene paper through dip-coating. ... 

Physisorption measurements showed that carbon nanomaterials exhibit rather meso- and macroporous structures (maximum micropore fraction, 15% see Table 2.1). The lowest specific surface area was measured with the platelet fiber catalyst exhibiting slightly more than 100 m2/g. The Co/HB material offers 120 m2/g of surface area, and the highest BET value was determined with the Co/ MW catalyst featuring nearly 290 m2/g. Carbon nanomaterials, though, are not really porous, as the space between the graphene layers is too small for nitrogen molecules to enter. The only location of adsorption is the external surface of the nanomaterials and the inner surface of the nanotubes. 

It is necessary to disperse the nanomaterials in the best possible manner, especially those layered structures such as graphite, graphene or clays. It is important to obtain very thin (ca. one nanometer) and very wide (ca. 500 nanometers) nanostructures dispersed in the polymer matrices to achieve optimal gas permeability and to improve their mechanical properties without affecting structural quality, using a small amount of the nanomaterial. The particle orientation also has an important effect on the properties of the nanocomposite. Nanoparticles need to be dispersed within the polymer so that are parallel to the material s surface. This condition ensures a maximum tor-... 

This technique involves the dispersion of a nanomaterial in a monomer (Fig. 4.8). This step requires a certain amount of time that depends on the polarity of the monomer molecules, the surface treatment of the nanomaterial, and the swelling temperature. For thermoplastics, the polymerization can be initiated either by the addition of an agent or by an increase in temperature. For thermosets such as epoxies or unsaturated polyesters, a curing agent or peroxide can be added in order to initiate the polymerization. Functionalized nanomaterials can improve their initial dispersion in the monomer and consequently in the composites. In the case of layered materials, such as clays or graphene, the most important step is the penetration of the monomer between the sheets, thus allowing the polymer chains to exfoliate the material. The... 

Fig. 3 Representative examples of carbon nanomaterials. Empty cage fullerenes (a) Cgo, (b) C70 endohedral fullerenes (c) La2 fA-Cgo, (d) Lu3N 4-C8o, (e) graphene sheet, (f) zig-zag single wall carbon nanombe, (g) arm chair single wall carbon nanombe, (h) chiral carbon nanombes, (i) carbon nanohom, (j) carbon nanoonion...

Two-dimensional, disc-shaped nanomaterials are the last class of nanomaterials to be discussed in more detail. Though a great variety of nanodiscs, nanosheets and nanoplatelets based on metals [256], metal oxides [257-260], graphene [261], or semiconductors [262] are frequently described in the literature, the vast majority of studies in liquid crystal systems dealt with some form of nanoclay. 

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