Grafting and electrografting of carbon (including nanotubes and diamond), metals, and metal oxides as well as hydrogenated silicon by diazonium salts provide an easy and efficient way to covalently modify the surface of these materials. Electrografting is achieved by electrochemical reduction, while grafting takes place by simple dipping of the material into a solution of the diazonium salt.5 The process can be run in either aprotic (CH_3CN) or aqueous media. The covalent bond between the substrate and the organic layer originates from the attack of the aryl radical obtained from the reduction of the diazonium salt. The calculated bonding energy ranges from 24 kcal/mol on gold to 70 kcal/mol on Si and up to 105 kcal/mol on carbon.
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