ABSTRACT
Being able to characterize and monitor the degree of dispersion of CNTs is important, as the level of CNT bundling directly determines –Š‡ ’”‘’‡”–‹‡• ‘ˆ –Š‡ †‹•’‡”•‹‘Ǥ Š‡ ϐ‹”•– ‘„•‡”˜ƒ–‹‘ –Šƒ– ‡šˆ‘Ž‹ƒ–‹‘‡ơ‡…–‹˜‡Ž›ƒ†‰”ƒ†—ƒŽŽ›‘……—”•™Š‡†‹•’‡”•‹‘• of CNTs in aqueous surfactant solutions are sonicated can be made with the bare eye: a longer sonication time results in a darker CNT •‘Ž—–‹‘ȋƒ•‡š‡’Ž‹ϐ‹‡† ‹ ‹‰—”‡͵ǤͳȌǡ™Š‹…Š ‹•ƒ ‹†‹…ƒ–‹‘–Šƒ– more and more CNTs are exfoliated and dispersed in the aqueous phase. For instance, after a certain sonication time at 20 W, that is to say, after about 5 min for Carbolex SWCNTs (Batch CLAP 8510 produced by arc-discharge technology, provided by Carbolex Inc.), and 90 min for more pure HiPCO SWCNTs (batch PO 257, produced „›ƒ”„‘ƒ‘–‡…Š‘Ž‘‰›…Ǥ—•‹‰ƒ‘†‹ϐ‹‡†‰ƒ•’”‘…‡••„ƒ•‡† ‘…Š‡‹…ƒŽ˜ƒ’‘”†‡’‘•‹–‹‘Ȍǡ‘•‹‰‹ϐ‹…ƒ–…Šƒ‰‡‘ˆ…‘Ž‘”‘ˆ–Š‡ dispersion can be observed anymore.
