275972 Surfactant Adsorption and Dispersion On Multi-Walled Carbon Nanotubes

Tuesday, October 30, 2012
Hall B (Convention Center )
Wipawan Mattavakul1 and Boonyarach Kitiyanan1,2, (1)The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand, (2)Center of Excellence on Petrochemical and Materials Technology, Bangkok, Thailand

The discovery of carbon nanotubes (CNTs) has inspired many researchers to innovate advanced materials for new applications since CNTs exhibit outstanding mechanical, electrical, and thermal characteristics. However, CNTs usually agglomerate due to strong van der Waals force, surface area, and hydrophobic interactions; these entanglements are able to cause many defects in composite materials. On the other hand, CNTs suspension is a significant factor to improve the properties of the original medium. To disperse CNTs, a number of methods are suggested. Some are based on covalent modification of the tubes, which inevitably leads to undesired deterioration of the CNT properties. Alternatively, non-covalent modification through amphiphilic self-assembly can be used to stabilize the dispersion of CNTs in aqueous solution, by the electrostatic repulsion or steric hindrance of the micelles formed around them, without changing their chemical and electrical property. While, surfactants are employed in CNT dispersions, surfactant molecules work by adsorption at the sold-liquid interface and self-accumulation into supramolecular structures. Therefore, the CNTs structures are maintained after the modification. The purpose of this work was to relate the adsorption behaviour of surfactants on multi-walled carbon nanotubes (MWCNTs) and MWCNTs dispersion. In this study, sodium dodecyl benzenesulfonate (SDBS), cetylpyridinium chloride (CPC) and polyoxyethylene octyl phenyl ether (OP(EO)10) were used as anionic, cationic and non-ionic surfactants, respectively. The adsorbed amount of surfactants on MWCNTs showed an order of SDBS > OP(EO)10 > CPC.  Moreover, the dispersion of MWCNTs at different concentrations was strongly affected by the charge of surfactant and alkyl chain length.

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See more of this Session: Poster Session: Nanoscale Science and Engineering
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