The effect of CNT functionalization on electrical and relaxation phenomena in MWCNT/chitosan composites

• Published in: Materials chemistry and physics 2015-04, Vol.155, p.252-261
• Main Authors: Zarate-Triviño, D.G., Prokhorov, E., Luna-Bárcenas, G., Mendez-Nonell, J., González-Campos, J.B., Elizalde-Peña, E., Mota-Morales, Josué D., Santiago-Jacinto, P., Terrones, M., Gómez-Salazar, S., Nuño-Donlucas, S.M., Sanchez, I.C.
• Format: Article
• Language: English
• Subjects: Biomaterials; Dielectric properties; Electrical properties; Microstructure
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2015.02.041

The effect of the type of CNT (functionalized and non-functionalized) on the dielectric relaxation phenomena and conductivity of MWCNT/chitosan (MWCNT/CS) was investigated. Composites were prepared by the solvent cast method by homogeneously dispersing CNT into a CS matrix. FTIR analysis suggests the formation of hydrogen bonding in functionalized-MWCNT/CS whereas the CS remains unaffected in non-functionalized films. In the low conductivity region, the α-relaxation process associated with a glass transition in CS is affected by the MWCNT; the Vogel temperature increases due to a decrease of the water content. The σ-relaxation exhibits a typical Arrhenius-type temperature dependence that is independent on the moisture content. Strong interfacial interactions of functionalized-MWCNT with the CS matrix are responsible for high values of the contact resistance Rc between individual CNT. Conversely, non-functionalized MWCNTs exhibit a typical 3D percolation threshold at ca. 4 wt %. [Display omitted] •Chemical interactions between MWCNTs and the chitosan matrix.•Critical concentration of MWCNTs in non-functionalized films 4 wt %.•The α-relaxation process affected by the MWCNT content.•Contact resistance Rc between individual MWCNTs embedded in the polymer matrix.