On the preparation of as-produced and purified single-walled carbon nanotube samples for standardized X-ray diffraction characterization

The aim of this research was to specify proper sample conditioning for acquiring representative X-ray diffraction (XRD) profiles for single-walled carbon nanotube (SWCNT) samples. In doing so, a specimen preparation method for quantitative XRD characterization of as-produced and purified arc-discharge SWCNT samples has been identified. Series of powder XRD profiles were collected at different temperatures, states, and points of time to establish appropriate conditions for acquiring XRD profiles without inducing much change to the specimen. It was concluded that heating in the 300–450 °C range for 20 minutes, preferably vacuum-assisted, and then sealing the sample is an appropriate XRD specimen preparation technique for purified arc-discharge SWCNT samples, while raw samples do not require preconditioning for characterization.

Graphical AbstractA sample preparation method for XRD characterization of as-produced and purified arc-discharge SWCNT samples is identified. The preparation technique seeks to acquire representative XRD profiles without inducing changes to the samples. Purified samples required 20 minutes of heating at (300–450)°C, while raw samples did not require preconditioning for characterization.Figure optionsDownload as PowerPoint slideHighlights
► Purification routines may induce adsorption onto the SWCNT samples.
► Heating a SWCNT sample may result in material loss, desorption, and SWCNTs closing.
► Raw arc-discharge samples do not require preparation for XRD characterization.
► Heating is appropriate specimen preparation for purified and heat-treated samples.
► XRD data fitting is required for structural analysis of SWCNT bundles.