Alkoxide-based precursors for direct drawing of metal oxide micro- and nanofibres

Abstract

The invention of electrospinning has solved the problem of producing micro-and nanoscaled metal oxide fibres in bulk quantities. However, until now no methods have been available for preparing a single nanofibre of a metal oxide. In this work, the direct drawing method was successfully applied to produce metal oxide (SnO 2 , TiO 2 , ZrO 2 , HfO 2 and CeO 2 ) fibres with a high aspect ratio (up to 10 000) and a diameter as small as 200 nm. The sol-gel processing includes consumption of precursors obtained from alkoxides by aqueous or non-aqueous polymerization. Shear thinning of the precursors enables pulling a material into a fibre. This rheological behaviour can be explained by sliding of particles owing to external forces. Transmission (propagation) of light along microscaled fibres and their excellent surface morphology suggest that metal oxide nanofibres can be directly drawn from sol precursors for use in integrated photonic systems.

Tin(ii) amide/alkoxide coordination compounds for production of Sn-based nanowires for lithium ion battery anode materials

“…All NMR samples were prepared using crystalline material handled under an argon atmosphere and then flame sealed under vacuum. Spectra were collected on a Bruker Avance 500 NMR spectrometer, using a 5 mm inverse probe, under standard experimental conditions: 1 H analysis was performed with a 4-second recycle delay at 16 scans; spectra were referenced to the toluene-d 8 peak at 2.09 ppm; 13 C spectra were obtained with a 10-second recycle delay and 4k scans and referenced to the methyl peak of the toluene-d 8 at 20.5 ppm; 119 Sn solution NMR analysis was performed with a 4-second recycle delay, and spectra were externally referenced to the secondary standard aqueous 1 M SnMe 4 at 0 ppm.…”

“…Previous routes for the production of SnO x nanowires for LIBs utilized a vapor-liquid-solid (VLS) mechanism from the thermal evaporation, 9,10 hard templating, 11 or salt melts. 12 Recently, a report by Tatte et al 13 was disseminated that employs a true sol-gel processing approach by a 'direct pull' process of metal tert-butoxide [M(OBu t ) y ] oils exposed to water to generate MO x (M = Sn, Ti, Zr, Hf, and Ce) nanowires with an aspect ratio of up to 10 000. These routes are complicated and/or expensive setups that not necessarily amenable to large scale production.…”

Electrospun ceria-based nanofibers for the facile assessment of catalyst morphological stability under harsh HCl oxidation reaction conditions

“…For our purpose, electrospinning is the perfect method for the preparation of nanofibers from various polymers, sol-gel-derived oxides and nanoparticle-based oxides [30,31]. The procedures for electrospinning of CeO 2 , Ce x Zr 1-x O 2 nanofibers have been reported recently [32][33][34][35][36].…”

Rheological Properties of MWCNT-Doped Titanium-Oxo-Alkoxide Gel Materials for Fiber Drawing

“…We have demonstrated earlier that the obtained liquids exhibit non-Newtonian visco-elastic behavior. That behavior, required for their use as fiber drawing dopes, is possible due to the arrangement of primary nanoclusters into secondary elongated units, which undergo sliding when external forces are applied [ 45 ].…”

“…After the rheological measurements, the fibers were drawn from the precursor samples by immersing a glass rod, ~5 mm in diameter, into it and pulling the rod off from the bulb at ~1 m/s speed [ 45 ]. The surface of the formed liquid precursor threads solidifies immediately in the lab atmosphere (relative humidity 20–50%, temperature 20 °C) after the reaction with water vapors in a surrounding atmosphere.…”