Effect of Ion-Pair Interaction Energy and Alkyl Chain Length on the Dispersibility of Carbon Nanotubes in a Conductive Composite Elastomer

• Published in: ACS applied polymer materials Vol. 2; no. 5; pp. 1773 - 1780
• Main Authors: Matsuno, Ryosuke, Takagaki, Yuusaku, Ito, Takamasa, Inoue, Sachie, Yoshikawa, Hitoshi, Takahara, Atsushi
• Format: Journal Article
• Language: English
• Published: American Chemical Society 08.05.2020
• Subjects: ion pair interaction energy; carbon nanotube (CNT); conductive composite elastomer; ionic liquid monomer; super growth single-walled carbon nanotube (SG-SWCNT)
• ISSN: 2637-6105; 2637-6105
• DOI: 10.1021/acsapm.9b01215

In this study, the effects of ion-pair interaction energy and the alkyl chain length of acryl-ionic copolymers on the dispersion state of supergrowth single-walled carbon nanotubes (SG-SWCNTs) in conductive composite elastomers was evaluated. The elastomers were synthesized from copolymers based on ionic monomers and acrylic monomers with various alkyl chain lengths (ethyl, butyl, octyl, and dodecyl). Composite elastomers containing SG-SWCNTs were prepared and characterized in terms of the conductivity and dispersibility of the SG-SWCNTs. The copolymers composed of monomeric 1-butyl-3-vinylimidazolium cations and trifluoromethanesulfonyl imide anions exhibited the lowest ion-pair interaction energy, and the dodecyl acrylate monomer with the longest alkyl chain tested was found to be the most effective for SG-SWCNT dispersion. However, the dispersibility of SG-SWCNTs and the conductivity of the composite appear to be inversely related. Long alkyl chains improved the dispersibility of the SG-SWCNTs. However, the formation of conductive pathways between CNTs was inhibited by covering the SG-SWCNTs with long, nonconductive alkyl chains. Thus, this work provides valuable information for the development of flexible electrodes.