General Remarks of Soft-Matter Nanotubes

Nanotubes have been undoubtedly becoming one of representative buzzwords in nano and nanobiotechnology. Carbon nanotubes made of carbon atom as well as tobacco mosaic virus self-assembled from identical protein units may come to your mind when you hear nanotubes. Moreover, diverse tubular architectures made of organic molecules including amphiphiles, synthetic polymers, proteins, and DNAs have recently emerged in large numbers and have demonstrated novel application fields that are different from those of the carbon nanotubes. Namely, we enter a new era, in which nanotubular structures can be fabricated from every substances and atomic elements. This chapter focuses on soft-matter nanotubes (SMNTs) made of organic molecular building blocks as mother components. In the beginning, the characteristic features of the SMNTs are compared with those of other nanoporous materials in terms of the surface features, interiors, and scaffolds. Historical background and representative fabrication method of the SMNTs are also discussed. Then, the author introduces the classification of formation pathways for the SMNT. Regarding each formation pathway, the major part of this chapter describes the characteristics of molecular building blocks, molecular arrangement in SMNT walls, one-dimensional interior nanospace, and diverse applications.