Stable Aqueous Solutions of Naked Titanate Nanotubes

Abstract

Aqueous solutions of naked nanotubes with Ti concentration up to 10 mM are obtained by hydrothermal synthesis followed by extensive ultrasound treatment. The morphology, surface characteristics, and solution behavior of the solubilized nanotubes are investigated. The time course of the solubilization process driven by ultrasound follows a first-order kinetic law and is mediated by the competition between Na(+) and H(+) for surface sites. The dynamics of interaction with small cations (i.e. the sodium ion) is studied by nuclear magnetic resonance spectroscopy and is demonstrated to be a multifaced process, since Na(+) is in part free to exchange between the binding sites on nanotubes and the bulk and in part is confined to slowly exchanging nanotube sites. The aqueous titanate nanotube solutions are stable for months, thus opening new perspectives for the use of this material in drug delivery and in homogeneous photocatalysis.

Investigation of the Cytotoxic Effects of Titanate Nanotubes on Caco-2 Cells

“…The aqueous solutions are stable for months. That may be the reason that TiNTs provide new possibilities for the formulation of oral drug delivery systems (16).…”

High-power sodium titanate anodes; a comparison of lithium vs sodium-ion batteries

“…The observed decrease in performance for all cells at high specific currents has been ascribed to kinetically-limited diffusion processes, although the larger size of the Na-ion versus Li-ions compared to the titanate interlayer spacing (ca. 8 Å) [18], may also have a role at limiting ionic diffusion for Na-ions at high specific currents. [78] Following the rate tests, long-term galvanostatic charge-discharge cycling tests at a specific current of 1000 mA g -1 for 400 cycles for both the Li-and Na-ion half-cells.…”

“…[6] Sodium titanates of the form Na2TinO2n+1, are characterized by zig-zagged edge-and corner-sharing TiO6 octahedra that form sheet layers with intercalating Na-ions located between them. [18] Sodium titanates based on the generic formula Na2Ti3O7, can possess a large interlayer spacing (of as large as ca. 8 Å), which can potentially facilitate excellent cycling performance in both Li-and Na-ion batteries, particularly under high-power conditions, [18] while possessing higher power densities than graphite.…”

“…[18] Sodium titanates based on the generic formula Na2Ti3O7, can possess a large interlayer spacing (of as large as ca. 8 Å), which can potentially facilitate excellent cycling performance in both Li-and Na-ion batteries, particularly under high-power conditions, [18] while possessing higher power densities than graphite. [19] These materials also possess one of the lowest insertion voltages for Na-ion cells at ca.…”

Electrospinning of in situ and ex situ synthesized polyimide composites reinforced by titanate nanotubes

“…In contrast, ulltrasonic treatment of the TiNT suspensions can successfully disintegrate such agglomerates, releasing single nanotubes. This process is also accompanied by the scission of nanotubes due to cavitation, resulting in a reduction in their length . Modification of the nanotube surface is a promising approach for facilitation of TiNT release into the solution without breaking of the nanotubes, which can improve the stability of the TiNT aqueous colloidal suspension .…”