Ultrasound-Assisted SWNTs Dispersion: Effects of Sonication Parameters and Solvent Properties

Autor: Elizabeth Gregan, Sourabhi Debnath, Qiaohuan Cheng, Hugh J. Byrne
Přispěvatelé: the Science Foundation Ireland Research Frontiers Program PHY037 2006. The Raman Instrument was purchased under the framework of the INSPIRE programme, funded by the Irish Government's Programme for Research in Third Level Institutions, Cycle 4, National Development Plan 2007-2013, supported by the European Union Structural Fund.
Rok vydání: 2010
Předmět:
Zdroj: Articles
ISSN: 1932-7455
1932-7447
DOI: 10.1021/jp101431h
Popis: Ultrasonication is widely used for preparing Single-Walled Carbon Nanotube (SWNT) dispersions in different solvent media and it has been shown to play a critical role in dispersing and debundling SWNTs. The strong shear force that can exfoliate the SWNT bundles during sonication comes from cavitation, which entails a process of bubble formation, growth, and collapse. The efficiency of the cavitation process is closely correlated to many solvent parameters, including vapor pressure, viscosity, and surface tension, as well as the sonication frequency, intensity, and time. In this study, SWNTs were dispersed in a range of organic solvents assisted by tip sonication. The effects of sonication intensity and time were investigated in o-dichlorobenzene (o-DCB) and dimethylformamide (DMF). The aggregation fraction below the dispersion limit of SWNTs in the range of organic solvents was found to be influenced by the solvent parameters, particularly solvent vapor pressure and viscosity. It is demonstrated that the parameters associated with the sonication process rather than solvent solubility parameters govern the dispersion process. It is further confirmed that significant degradation of the SWNTs is affected during the dispersion process.
Databáze: OpenAIRE