Inner-tubular physicochemical processes of carbon nanotubes

Nanosized inner cavities of carbon nanotubes (CNTs) afford quasi-one-dimensional (1D) confined space, in which materials adsorbed or filled are of reactivity greatly different from the materials adsorbed on a planar surface and quite a number of curious physicochemical processes will possibly occur. In other words, 1D CNT nanochannels may serve as “nanosized test tubes”. In this article, on the basis of the unique chemical and physical properties of CNTs, the latest progresses of the research on peculiar inner-tubular physicochemical processes of CNTs are briefly reviewed from several aspects. The extraordinary 1D adsorption, capillary filling and nanoscale-confined reaction are discussed in detail. Moreover, the characteristics of “nanosized test tubes” are summarized and many unfamiliar inner cavity chemical processes are expected. Finally, the future direction and challenges on basic researches and potential applications of inner-tubular chemistry of CNTs are discussed.