Effect of an organic polymer in purification and cutting of single-wall carbon nanotubes

A mixture of as-grown single-wall carbon nano-tubes (SWNTs) and a monochlor obenzene (MCB) solution of polymethylmethacrylate (PMMA) was sonicated and homogenized. As a result, SWNTs were separated from carbonaceous impurities and metal particles, which enabled us to purify the SWNTs by filtration. W e also found that the number of short (about 1-mu m) SWNTs and thin bundles of SWNTs increased. The thin bundles contained one to three SWNTs. These s hort, thin SWNTs suspended in the MCB solution of PMMA were spin-coated ont o a Si wafer, and could be dispersed on it.