Structure of single-wall carbon nanotubes purified and cut using polymer

Following on from our previous report that a monochlorobenzene solution of poly methylmethacrylate is useful for purifying and cutting single-wall car bon nanotubes (SWNTs) and thinning SWNT bundles, we show in this report tha t polymer and residual amorphous carbon can be removed by burning in oxygen gas. The SWNTS thus obtained had many holes (giving them a worm-eaten look ) and were thermally unstable. Such severe damage caused by oxidation is un usual for SWNTs; we think that they were chemically damaged during ultrason ication in the monochlorobenzene solution of polymethylmethacrylate.