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Behavior Of Na+-Polystyrene Sulfonate At The Interface With Single-Walled Carbon Nanotubes (Swnts) And Its Implication To Swnt Suspension Stability, Tabbetha A. Dobbins, Richard Chevious, Yuri Lvov
Behavior Of Na+-Polystyrene Sulfonate At The Interface With Single-Walled Carbon Nanotubes (Swnts) And Its Implication To Swnt Suspension Stability, Tabbetha A. Dobbins, Richard Chevious, Yuri Lvov
Tabbetha A. Dobbins
The assembly of sodium polystyrene sulfonate (Na+-PSS) at the surface of single-walled carbon nanotubes (SWNTs) in pH 3 aqueous solution is described. Rather than forming linear or sheet-like chain morphologies over SWNT surfaces, Na+-PSS adopts a spherically collapsed conformation believed to be the result of cation (either Na+ or H+) condensation onto the ionized polymer chain. It is well reported that cations (and also anions) adsorb preferentially onto single-walled and multi-walled carbon nanotube surfaces leading to an increased ion concentration in the near surface regions relative to the bulk solution. This work provides experimental evidence for preferentially absorbed cation condensation …
Study Of Morphological Changes In Mgh2 Destabilized Libh4 Systems Using Computed X-Ray Microtomography, Tabbetha A. Dobbins, Shathabish Narasegowda, Leslie G. Butler
Study Of Morphological Changes In Mgh2 Destabilized Libh4 Systems Using Computed X-Ray Microtomography, Tabbetha A. Dobbins, Shathabish Narasegowda, Leslie G. Butler
Tabbetha A. Dobbins
The objective of this study was to apply three-dimensional x-ray microtomographic imaging to understanding morphologies in the diphasic destabilized hydride system: MgH2 and LiBH4. Each of the single phase hydrides as well as two-phase mixtures at LiBH4:MgH2 ratios of 1:3, 1:1, and 2:1 were prepared by high energy ball milling for 5 minutes (with and without 4 mol % TiCl3 catalyst additions). Samples were imaged using computed microtomography in order to (i) establish measurement conditions leading to maximum absorption contrast between the two phases and (ii) determine interfacial volume. The optimal energy for measurement was determined to be 15 keV …