caa a22 4500 445371420 CHVBK 20180317142948.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s00340-011-4709-7 doi (NATIONALLICENCE)springer-10.1007/s00340-011-4709-7 Flame temperature trends in reacting vanadium and tungsten ethoxide fluid sprays during CO2-laser pyrolysis [Elektronische Daten] [B. Mwakikunga, A. Mudau, N. Brink, C. Willers] We observe the "invisible-to-the-naked-eye” flames of tungsten and vanadium ethoxide aerosols when ignited at moderate laser excitation (0<P laser<70 W) by employing an IR thermo-graphic camera. No emission is seen in the visible range whether by the visible region cameras or by spectroscopy. The emissivity of the precursor solution measured was 0.80 and 0.75 for tungsten and vanadium ethoxide, respectively. The spectral emissivities of the tungsten and vanadium ethoxide flames measured using FTIR-spectrometer were used to calculate the pyrolysis flame temperature at various laser intensities and wavelengths. New energy balance equations have been derived—the transient temperature one extended from Haggerty-Cannon equation and the other based on standard resonance analysis. Fitting these models to experimental data reveals that only small amounts (1.33% and 4.32%, respectively) of the laser power are used in the pyrolysis of the precursor ethoxide aerosols into the desired oxide nanostructures. The low levels of specific heat capacity values obtained in these sprays suggest that these are electronic heat capacities rather than lattice heat capacities; enthalpies are also obtained. The experimental temperature-laser power trends observed were in agreement with previous findings from Tenegal et al. (Chem. Phys. Lett. 335:155, 2001). The damping coefficients, and hence the saturation intensities confirm that the vanadium containing precursor liquid is harder to dissociate into final products than the tungsten precursor as observed experimentally. The Author(s), 2011 Mwakikunga B. DST/CSIR National Centre for Nano-Structured Materials, P.O. Box 395, 001, Pretoria, South Africa aut Mudau A. CSIR Defence, Peace, Safety and Security (DPSS), P.O. Box 395, 001, Pretoria, South Africa aut Brink N. DENEL Dynamics, Nelmapius Drive, Centurion, P.O. Box 7412, 0046, Centurion, South Africa aut Willers C. CSIR Defence, Peace, Safety and Security (DPSS), P.O. Box 395, 001, Pretoria, South Africa aut Applied Physics B Springer-Verlag 105/2(2011-11-01), 451-462 0946-2171 105:2<451 2011 105 340 https://doi.org/10.1007/s00340-011-4709-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00340-011-4709-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mwakikunga B. DST/CSIR National Centre for Nano-Structured Materials, P.O. Box 395, 001, Pretoria, South Africa aut NATIONALLICENCE 700 1- Mudau A. CSIR Defence, Peace, Safety and Security (DPSS), P.O. Box 395, 001, Pretoria, South Africa aut NATIONALLICENCE 700 1- Brink N. DENEL Dynamics, Nelmapius Drive, Centurion, P.O. Box 7412, 0046, Centurion, South Africa aut NATIONALLICENCE 700 1- Willers C. CSIR Defence, Peace, Safety and Security (DPSS), P.O. Box 395, 001, Pretoria, South Africa aut NATIONALLICENCE 773 0- Applied Physics B Springer-Verlag 105/2(2011-11-01), 451-462 0946-2171 105:2<451 2011 105 340 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer