Modification of carbon

The scope of tire following article is to survey the physical and chemical properties of tire tliird modification of carbon, namely [60]fullerene and its higher analogues. The entluisiasm tliat was triggered by tliese spherical carbon allotropes resulted in an epidemic-like number of publications in tire early to mid-1990s. In more recent years tire field of fullerene chemistry is, however, dominated by tire organic functionalization of tire highly reactive fullerene... 

Not too long ago, graphite and diamond were the only two known modifications of carbon. That changed dramatically with the discovery of in 1985 and all the higher fullerenes soon thereafter. Nevertheless, this breakthrough did not stand alone in paving the way to the new era of chemical and physical research into carbon rich compounds that we are now enjoying. 

Modification of carbon materials by tri-nuclear complexes of 3d-metals with ethanolamine ligands increases the catalytic activity with regard to the electrochemical reaction of oxygen reduction. The Co-Ni complex is most active in this reaction if pyrolyzed at 600°C. 

Apart from the traditional organic and combinatorial/high-throughput synthesis protocols covered in this book, more recent applications of microwave chemistry include biochemical processes such as high-speed polymerase chain reaction (PCR) [2], rapid enzyme-mediated protein mapping [3], and general enzyme-mediated organic transformations (biocatalysis) [4], Furthermore, microwaves have been used in conjunction with electrochemical [5] and photochemical processes [6], and are also heavily employed in polymer chemistry [7] and material science applications [8], such as in the fabrication and modification of carbon nanotubes or nanowires [9]. 

A. Vakurov, C.E. Simpson, C.L. Daly, T.D. Gibson, and P.A. Millner, Acetylcholinesterase-based biosensor electrodes for organophosphate pesticide detection I. Modification of carbon surface for immobilization of acetylcholinesterase. Biosens. Bioelectron. 20, 1118-1125 (2004). 

After different allotropic modifications of carbon nanostructures (fullerenes, tubules) have been discovered, a lot of papers dedicated to the investigations of such materials, for instance [9-15] were published, determined by the perspectives of their vast application in different fields of material science. 

In recent years, CNTs have been receiving considerable attention because of their potential use in biomedical applications. Solubility of CNTs in aqueous media is a fundamental prerequisite to increase their biocompatibility. For this purpose several methods of dispersion and solubilisation have been developed leading to chemically modified CNTs (see Paragraph 2). The modification of carbon nanotubes also provides multiple sites for the attachment of several kinds of molecules, making functionalised CNTs a promising alternative for the delivery of therapeutic compounds. 

In order to overcome this drawback, there are two main approaches for the surface modification of carbon nanostructures that reoccur in the literature. The first one is covalent functionalization, mainly by chemical bonding of functional groups and the second one is noncovalent functionalization, mainly by physical interactions with other molecules or particles. Both strategies have been used to provide different physical and chemical properties to the carbon nanostructures. Those that will be presented here are only a few examples of the modifications that can be achieved in carbon nanostructure surfaces and composite fabrication. 

L. Dai, A. W. H. Mau, Controlled synthesis and modification of carbon nanotubes and C60 Carbon nanostructures for advanced polymeric composite materials, Advanced Materials, vol. 13, pp. 899-913, 2001. 

N. Karousis, N. Tagmatarchis, Current progress on the chemical modification of carbon nanotubes, Chemical Reviews, vol. 110, pp. 5366-5397, 2010. 

A great number of methods for the modification of carbon substituents on pyrazines have been developed, and the functionalization of the methyl group is discussed first. 

Modification of the activated carbon sorbent by neutral anolite solution in situ solves another important problem associated with the need to use anticoagulants for prevention of thrombosis within a hemosorbent. Oxidizing modification of carbon with ON solution considerably reduces the required doses of anticoagulants such as heparin or solutio glugicirum (a solution of 2% of sodium hydrocitrate and 3% glucose) and decreases the risk of postoperative complications associated with an imbalance of the coagulation system. 

Akovali and Ulkem [33] reported the surface modification of carbon black by plasma polymerization of styrene and butadiene. The effect of such plasma-coated carbon black was studied in a SBR matrix. A slight increase in the tensile strength was observed for the plasma-polymerized styrene-coated carbon black. This was explained by a decrease in the interfacial tension, as the result of the similarities between the treated filler and the matrix at the interface. They also concluded that the plasma coating obtained on carbon black is so thin that no blockage of the pores occurred and that there was no decrease in the original absorptive capacity. 

Later, Kang et al. [35] reported surface modification of carbon black using various monomers like acetylene, acrylic acid, butadiene, and oxygen. They concluded that it is possible to manipulate the surface properties of carbon black using plasma polymerization. 

Kang YC, van Ooij WJ (2006) RF plasma polymerization for surface modification of carbon black rubber filler. ACS Rubber Division Meeting, Cincinnati, 2006. ACS, Akron, Ohio,... 

Mathew T (2008) Surface modification of carbon black by plasma polymerization. Enschede, The Netherlands, Ph.D. thesis. ISBN 978-90-365-2724-8... 

---