Comparison of Characteristics of Single-Walled Carbon Nanotubes Obtained by Super-Growth CVD and Improved-Arc Discharge Methods Pertaining to Interfacial Film Formation and Nanohybridization with Polymers

Abstract A comparison of single-walled carbon nanotubes (SWCNTs) produced by super-growth chemical vapor deposition (CVD) and improved-arc discharge methods was performed as it pertains to the formation of their Langmuir-Blodgett films and polymer-based nanocomposite preparation. Two kinds of SWCNTs indicated amphipathic properties after surface chemical modification using long-chain phosphonic acids. The modification rates of the two types of organo-modified SWCNTs were almost the same, impurities were removed to the same extent, and the influence of the tube length distribution was considered to be low. However, it was expected that the SWCNTs made via improved-arc discharge would be superior in regularity in the two-dimensional film. Specifically, the arrangement regularity of the modified chains was high, and as a result, the layering regularity of SWCNTs itself was considered to be high. Owing to organo-modification, SWCNTs manufactured via the super-growth CVD method tended to be dispersed into finer fibers even in a monolayer. Compared to other organic polymers, this organo-modified SWCNT formed a composite material with higher dispersibility. The significant difference in the physical properties of both SWCNTs constitutes a trade-off relationship between dispersibility and two-dimensional regularity. The difference in the physical properties of the two types of SWCNTs could be related to the strength of the interaction between the exposed SWCNT-specific surfaces, even after organo-modification.