Solid carbon-based materials

The structure-property relations of fullerenes, fullerene-derived solids, and carbon nanotubes are reviewed in the context of advanced technologies for carbon-based materials. The synthesis, structure and electronic properties of fullerene solids are then considered, and modifications to their structure and properties through doping with various charge transfer agents are reviewed. Brief comments are included on potential applications of this unique family of new materials. 

The development of new transducing materials for DNA analysis is a key issue in the current research efforts in electrochemical-based DNA analytical devices. The use of platinum, gold, indiiun-tin oxide, copper solid amalgam, mercury and other continuous conducting metal substrates has been reported [6]. However, this chapter is focused on carbon-based materials and their properties for immobihzing DNA by simple adsorption procedures. 

Therefore, it became clear that those methods are reliable tools to detect, to analyze and to optimize all sorts of materials, and in many cases they already turn out to be some sort of cheap, fast and reliable alternative to standard experimental methods in materials science. But still, a lot of work is needed to be done in gaining a more profound experience in what could be called materials engineering , which means systematical understanding and development of new nanoscaled materials with definite properties, and in looking for the mechanism of the so called self-assembling of boron- and carbon-based materials to propose, predict and create nanodevices towards manufacturing of useful solids [1]. 

A solid-state solar cell was assembled with an ionic liquid—l-ethyl-3-methylimidazolium bis(trifluoromethanesulfone)amide (EMITFSA) containing 0.2 M lithium bis(trifluoromethanesulfone)amide and 0.2 M 4-tert-butylpyridine—as the electrolyte and Au or Pt sputtered film as the cathode.51,52 The in situ PEP of polypyrrole and PEDOT allows efficient hole transport between the ruthenium dye and the hole conducting polymer, which was facilitated by the improved electronic interaction of the HOMO of the ruthenium dye and the conduction band of the hole transport material. The best photovoltaic result ( 7p=0.62 %, 7SC=104 pA/cm2, FOC=0.716 V, and FF=0.78) was obtained from the ruthenium dye 5 with polypyrrole as the hole transport layer and the carbon-based counterelectrode under 10 mW/cm2 illumination. The use of carbon-based materials has improved the electric connectivity between the hole transport layer and the electrode.51... 

The present paper is concerned with hydrogen storage in different crystalline solids. Such solids can be metal hydrides, carbon-based materials, and microporous materials. 

The choice of the sorbent is dictated by the characteristics of both the analytes and their potential interferences. The sorbents most frequently employed here are silica, alkylsilane-modified silica (bonded phases), alumina, porous polymers (with and without ion-exchange groups) and carbon-based materials. One typical application is a method for the determination of hexavalent chromium in soils [10] using the on-line system depicted in Fig. 4.9. After USAL, the analytes in the leachate were directly determined or preconcentrated depending on their concentration. Concentration was performed by on-line solid-phase extraction using a laboratory-made minicolumn packed with a strong anion-exchange resin. The absolute limits of detection were 4.52 and 1.23 ng without and with preconcentration, respectively. 

Solid fuels other than carbon-based materials can also be agglomerated to obtain specific properties. For example, in recent developments spherical agglomerates are produced from enriched uranium powder as a fuel for specific nuclear reactors (Section 6.10.3). Tab. 6.10-1 lists some of those solid fuels that have been or are being processed most commonly with agglomeration technologies to improve their properties for various applications. 

Activated carbons were the first adsorbents to be developed. As stated in previous sections, activated carbons are produced from a solid carbonaceous based material, which is non-graphitic and non-graphitizable, and has an initial isotropic structure. The precursor is transformed or activated by means of medium to high temperature treatments, which remove solid mass, and at the same time, create pores where the removed mass was previously located. The common properties of activated carbons and other kinds of carbon adsorbents is their well developed pore network, and the similar ways in which they are... 

The first part of this chapter is intended to survey recent literature on new catalytic materials because the development of new types of metal oxides and layered- and carbon-based materials with different morphologies opens up novel acid-base catalysis that enables new type of clean reaction technologies. Mechanistic considerations of acid- and base-catalyzed reactions should result in new clean catalytic processes for Green and Sustainable Chemistry, for example, transformations of biorenewable feedstock into value-added chemicals and fuels [21-35]. The latter part of this chapter, therefore, focuses on biomass conversion using solid acid and base catalysts, which covers recent developments on acid-base, one-pot reaction systems for carbon-carbon bond formations, and biomass conversion including synthesis of furfurals from sugars, biodiesel production, and glycerol utilization. 

The carbon strucmres we noted in the opening Insight section in this chapter do not readily exist in liquid phases. To melt diamond or graphite requires temperatures that are high enough that there are no practical consequences of the liquid phases. There are, however, carbon-based materials that have important properties in both the solid and liquid states, and they comprise a sizable portion of the materials used in modern engineering designs. Before we can move on past our smdy of materials, we need to take another look at polymers—particularly carbon-based polymers. 

In solids, the component of conduction must be added to the dielectric properties. This is especially critical in semi-conductive particles, like carbon based materials. Under microwave radiation, conductive particles loose energy through their displacement. This complicates the estimation of absorption energy, characterized by the equivalent dielectric conductivity, cj, and a loss parameter of a/uteQ. This term increases with increasing temperature. This effect, named thermal runaway, comphcates the control of homogeneous temperature heating. 

Of practical importance is the contribution that is made by carbonaceous materials as an additive to enhance the electronic conductivity of the positive and negative electrodes. In other electrode applications, carbon serves as the electrocatalyst for electrochemical reactions and/or the substrate on which an electrocatalyst is located. In addition, carbonaceous materials are fabricated into solid structures which serve as the bipolar separator or current collector. Clearly, carbon is an important material for aqueous-electrolyte batteries. It would be very difficult to identify a practical alternative to carbon-based materials in many of their battery applications. The attractive features of carbon in electrochemical applications are its high electrical conductivity, acceptable chemical stability, and low cost. These characteristics are important for the widespread acceptance of carbon in aqueous electrolyte batteries. 

In the case of some microelectromechanical systems (MEMSs), a solder reflow step is used for their assembly processes, which requires all electronics to be heated above 250°C. At the moment, lithium metal cannot be used as the negative electrode film since its melting point is only 180°C. From the discussion in Chapters 7 and 8, it follows that carbon-based and non-carbon-based materials can be used as negative electrodes. Similarly, they can also act as negative electrode materials for the solid micro-lithium-ion battery. For example. 

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