Polymers containing fullerene or carbon nanotube structures

This review deals with recent progress in studies of polymeric covalent and noncovalent modifications of fullerenes (mainly C-60) and carbon nanotubes (CNTs), and their applications. By using functional polymers to react with fullerenes, or synthesizing polymers in the presence of fullerenes, various kinds of polymeric fullerenes can be prepared: side-chain polymers, main-chain polymers, dendritic fullerenes, star-shaped polymers, fullerene end-capped polymers, etc. Furthermore, by controlling the functional groups in polymer chains and reaction conditions, many well-defined fullerene polymers have been prepared. 'Living' polymerization methods have also been introduced for preparation of fullerene polymers, e.g. anionic polymerization, iniferter technique, stable free radical polymerization, and atom-transfer free-radical polymerisation. With these living methods, both the architecture of the fullerene polymers and the grafted polymer chains can be well-controlled. All of these methods establish a good platform for developing applications of fullerene polymers. The synthesis of polymeric CNTs is only in its infancy. However, present results show promise that the combination of the unique properties of CNTs with functional polymers will lead to novel materials with unusual mechanical, electrical, magnetic, and optical properties. Doping of polymeric systems with fullerenes in is also a very important research area, especially for preparation of electronic and optical materials. Both conducting and conventional polymers can be used as matrices in the preparation of functional composites. The structures and properties of these composites are strongly dependent on the properties and concentrations of the active components. CNT-doped polymers have also been prepared and show interesting properties. The combination of the unique properties of fullerenes and CNTs with polymers makes these materials potential candidates for many applications, such as data storage media, photovoltaic cells and photodiodes, optical limiting devices, photosensitive drums for printers, and so on. The applications of polymeric fullerenes and CNTs are also reviewed in this article. (C) 2004 Elsevier Ltd. All rights reserved.