Carbon nanotubes: synthesis, characterization, functionalization and biomedical applications

Recent decades have seen significant progress in research on carbon nanotubes (CNTs), especially in controllable synthesis, scale-up of production, and application developments for this material. This sp۲-bonded carbon nanocarbon uniquely combines excellent mechanical strength, extremely high electrical conductivity, and many other superior properties, making it attractive for basic research and industrial applications. In recent decades, the production capacity of CNTs has reached more than thousands of tons per year, dramatically reducing the price of CNTs. This article reviews the history, types of structures, characterization methods, functionalization, and incredibly different synthesis methods for preparing carbon nanotubes, including electric arc discharge, laser ablation, and chemical vapor deposition. Moreover, the applications of CNTs in various necessary biomedical fields are discussed in detail. Finally, the prospects of CNTs are outlined in terms of their commercial applications.