title: Assessing the temporal stability of surface functional groups introduced by plasma treatments on the outer shells of carbon nanotubes.
abstract: Plasma treatments are emerging as superior efficiency treatment for high surface to volume ratio materials to tune functional group densities and alter crystallinity due to their ability to interact with matter at the nanoscale. The purpose of this study is to assess for the first time the long term stability of surface functional groups introduced across the surface of carbon nanotube materials for a series of oxidative, reductive and neutral plasma treatment conditions. Both plasma duration dose matrix based exposures and time decay experiments, whereby the surface energy of the materials was evaluated periodically over a one-month period, were carried out. Although only few morphological changes across the graphitic planes of the carbon nanotubes were found under the uniform plasma treatment conditions, the time dependence of pertinent work functions, supported by Raman analysis, suggested that the density of polar groups decreased non-linearly over time prior to reaching saturation from 7 days post treatment. This work provides critical considerations on the understanding of the stability of functional groups introduced across high specific surface area nano-materials used for the design of nano-composites, adsorptive or separation systems, or sensing materials and where interfacial interactions are key to the final materials performance.
authors: Deakin University, Geelong, Institute for Frontier Materials, 3216 VIC, Australia.
authors: Andrea
authors: A
authors: Merenda
authors: Deakin University, Geelong, Institute for Frontier Materials, 3216 VIC, Australia.
authors: Elise des
authors: Ed
authors: Ligneris
authors: CSIRO Manufacturing, Clayton - 3149 VIC, Australia.
authors: Kallista
authors: K
authors: Sears
authors: Deakin University, Geelong, Institute for Frontier Materials, 3216 VIC, Australia.
authors: Thomas
authors: T
authors: Chaffraix
authors: Deakin University, Geelong, Institute for Frontier Materials, 3216 VIC, Australia.
authors: Kevin
authors: K
authors: Magniez
authors: Institut Européen des Membranes, IEM, UMR-5635, Université de Montpellier, ENSCM, CNRS, Place Eugène Bataillon, 34095 Montpellier cedex 5, France.
authors: David
authors: D
authors: Cornu
authors: CSIRO Manufacturing, Waurn Ponds - 3216 VIC, Australia.
authors: Jürg A
authors: JA
authors: Schütz
authors: Deakin University, Geelong, Institute for Frontier Materials, 3216 VIC, Australia.
authors: Ludovic F
authors: LF
authors: Dumée