Engineered polymer nanotubes

It is well accepted that the good properties of the isotactic polypropylene as an engineering polymer matrix in thermoplastic composite materials and engineering blends are seriously affected by the inability of this polymer to develop an adequate level of interfacial interaction with polar components such as mineral fillers (calcium carbonate) and reinforcements (talc, mica, wollastonite), synthetic reinforcements (glass fibers, carbon fibers, and nanotubes), or engineering polymers such as polyamide, aliphatic polyesters, and so on. 

Other, nanometer-scale forms of carbon, such as nanotubes and graphenes, have been proposed as ESD fillers, though their early use may be greater with engineering polymers. Carbon nanotubes (CNTs), in diameters of lO-lOOnm, can induce the conductivity needed for electrostatically paintable plastic automotive body panels, for example. They are also said to be replacing carbon black and fiber in small, detailed electronics applications [6-5]. 

Engineering polymers can be reinforced by the inclusion in their formulations of glass fibres, carbon fibres and nanotubes which produce appreciable improvements in mechanical and thermal properties. 

In the past decade, nanoscale particles with excellent electrical properties and anisotropic dimensions, such as carbon nanotubes and metallic nanowires, have sparked considerable interest in the field of polymer composites. The high conductivity and unique geometry of these nanoparticles can increase the electrical conductivity of typical engineering polymers by S cm at very low filler concentrations (< 1 vol.%). Realizing the full commercial potential of these novel materials hinges upon our ability to produce composites with well-defined and controllable properties. This, in turn, requires an in-depth understanding of the stmcture-property relations for the electrical properties of polymer nanocomposites. 

B. Sitharaman, X.F. Shi, X.F. Walboomers, H.B. Liao, V. Cuijpers, L.J. Wilson, A.G. Mikos, J.A. Jansen, In vivo biocompatibility of ultra-short single-walled carbon nanotube/biodegradable polymer nanocomposites for, bone tissue engineering, Bone, vol. 43, pp. 362-3Z0, 2008. 

In the future, nanotubes and nanofibers can be administered systemically, if the problem of their toxicity is addressed, for example, by appropriate polymer coating. In this respect, the continuous nanofibers are more likely to be used in implants or tissue engineering applications. 

The extraordinary mechanical, thermal and electrical properties of carbon nanotubes (CNT) have prompted intense research into a wide range of applications in structural materials, electronics, and chemical processing.Attempts have been made to develop advanced engineering materials with improved or novel properties through the incorporation of carbon nanotubes in selected matrices (polymers, metals and ceramics). But the use of carbon nanotubes to reinforce ceramic composites has not been very successful. So far, only modest improvements of properties were reported in CNTs reinforced silicon carbide and silicon nitride matrix composites, while a noticeable increase of the fracture toughness and of electrical conductivity has been achieved in CNTs reinforced alumina matrix composites. ... 

Venkatesan, J., Qian,Z.-J., Ryu, B., Ashok Kumar, N., and Kim, S.-K. (2011a). Preparation and characterization of carbon nanotube-grafted-chitosan— Natural hydroxyapatite composite for bone tissue engineering. Carbohydr. Polym. 83,569-577. 

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