Single-walled carbon nanotubes (SWCNTs) have attracted a lot of attention as a result of their various applications, for instance, transistors, supercapacitors, sensors and so on. However, the industrial applications of SWCNTs have been hindered by their insolubility in many solvents. In order to improve their handling processes, we have investigated an excellent and photochemically tunable dispersant for SWCNTs, based on photoreaction of the dispersant in aqueous solution. The dispersant can be utilized in some application fields of SWCNTs. By the combining procedure, high-speed centrifugation using the dispersant, we have demonstrated a new purification method for SWCNTs without destroying the intrinsic SWCNT structures. Photopatterned SWCNT thin films are easily fabricated by adsorption/desorption processes of the dispersant in solid films.

Vesicles have a bilayer membranous structure composed of amphiphilic substances con taining aqueous phase in its core and can encapsulate drug ingredients to act as drug delivery sys tems, a bio-membrane model, and so on. Vesicles also find their applications in cosmetics and foods industries since they can not only entrap water-soluble substances in their core, but also solubilize oily substances in the bilayer membrane. In this article, we have studied factors governing the formation and dispersion stability of vesicles in terms of molecular structure of amphiphiles and bending elastic modulus of bilayer. The vesicles formed with high dispersion stability at some mixed surfactant compositions are discussed. Finally, these vesicles are used as structure directing agent for preparation of silica hollow nanoparticles.