SWCNT surface damage

Consequently, stopping the sonication when the maximum amount of exfoliable CNTs has been unbundled [e.g., at 100,000 J for HiPCO SWCNTs] should prevent further cutting of the SWCNTs, though SWCNT surface damage may not be particularly minimized. 

The mechanism of MWCNT de-entanglement is expected to be very similar to the one described for SWCNTs, although the initial state is different. Note that if the sonication treatment is too aggressive and/ or lasts too long, it can lead to local damage of the CNT walls, if not to CNT shortening. Local damage deteriorates both electrical and mechanical properties. At the end of the sonication process, a dispersion of mainly individual CNTs with adsorbed surfactant molecules on their surface is obtained. 

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