ABSTRACT
In order to make technologically performing conductive materials, it is crucial to be able to monitor and optimize each step of the latexbased process to make nanocomposites. In particular, this applies –‘–Š‡ϐ‹”•–•–‡’‘ˆ–Š‡’”‘…‡••ǡƒ†‹’Ž‹‡•–Š‡‘’–‹‹œƒ–‹‘‘ˆ–Š‡ CNT individualization process, the minimization of the amount of impurities in the CNT batch, as well as the limitation of the possible †ƒƒ‰‡‘ˆ–Š‡™ƒŽŽ•ȋ‹†—…‡†„›–”‡ƒ–‡–•—…Šƒ•’—”‹ϐ‹…ƒ–‹‘ and sonication). –Š‡ ϐ‹”•– ’ƒ”–ǡ –Š‹• …Šƒ’–‡” ”‡˜‹‡™• •‡˜‡”ƒŽ ‡š’‡”‹‡–ƒŽ techniques that are suitable to monitor the sonication-driven debundling of CNTs in aqueous surfactant solutions. These are: microscopy techniques (cryo-)TEM, SEM, AFM, and optical microscopy, dynamic light scattering, and Raman and UV-Vis spectroscopy. It can be concluded from the comparison of these techniques that the UV-Vis spectroscopic technique is a very simple, reproducible and semi-quantitative technique to use for this purpose. In particular, it enables one to determine when the debundling of the CNTs is as complete as possible, and thus indicates when the sonicating process should be stopped, limiting this way any unnecessary damage of the CNT induced by sonication. Additionally, sample preparation is quick, easy and cheap. Data analysis is relatively straightforward, too. Ǧ‹•Ǧ•’‡…–”‘•…‘’›…ƒ„‡ ˆ—”–Š‡”‘’–‹‹œ‡†ƒ† ”‡ϐ‹‡† –‘ƒ••‡”–ƒ†…‘’ƒ”‡–Š‡‡ˆϐ‹…‹‡…›‘ˆ’—”‹ϐ‹…ƒ–‹‘–‡…Š‹“—‡•ǤŠ‹• will also help calculate the true CNT concentration and the exact composition, in terms of diameter and electronic structures (the latter being tuned by a careful choice of surfactant and experimental conditions) of the supernatant of centrifuged surfactant-CNT dispersions.
