Size dependence of complex refractive index function of growing nanoparticles

Soot modeling of counterflow diffusion flames of ethylene-based binary mixture fuels

“…EðmÞ and FðmÞ are functions of the complex refractive indexm which was assumed to be a constant with a value of 1.57-0.56i [79]. Although some recent studies (e.g., in [83]) indicated that the refractive index depends on particle size, reliable data regarding the variation ofm in a narrow soot zone in counterflow diffusion flames are not available. Note, however, that since the particle sizes are comparable in the four tested flames, a relative comparison among the cases with ethylene fuel and binary fuel mixtures may not be influenced by the choice of constantm.…”

Investigation of the size of the incandescent incipient soot particles in premixed sooting and nucleation flames of n-butane using LII, HIM, and 1 nm-SMPS

“…The spectral dependence of E(m) has a strong implication for the soot temperature inferred from 2C-LII: assuming a wavelength-independent E(m) in the visible leads to a higher soot temperature than assuming an increasing E(m) with decreasing wavelength. In an attempt to investigate the size dependence of E(m) at 1064 nm for growing carbon particles during acetylene pyrolysis, Eremin et al obtained E(m) values as small as about 0.05 (Eremin et al 2011). Caution should be taken regarding the E(m) values derived from these 2C-LII studies using the methodology of Snelling et al (2004), since the product r s c s of mature soot was used for young soot.…”

Experimental study of temperature influence on carbon particle formation in shock wave pyrolysis of benzene and benzene–ethanol mixtures

“…here t -is the reaction time, I 0 and I -are the incoming and transmitted laser light intensities respectively, k -is a diagnostic wavelength, l -is the optical path length, E(m) -is the refractive index function of particle material, which is a priori unknown and in general is dependent on the diagnostic wavelength [14,15] and the carbon particle size [16,17]. Therefore in the present analysis the product of volume fraction of condensed phase f v and the function of refractive index E(m):…”

“…The measured Ti-Re LII signal was fitted by calculated curves obtained by variation of the count median diameter and at constant value of the standard deviation r = 1.1 in the lognormal distribution function using the least-squares method. The LII model, the method of evaluation of mean particle size and estimation of measurement error are described in detail in [17]. The following main assumptions are assumed.…”

“…The particle size was determined by approximation of the experimental Ti-Re LII trace obtained at the wavelength 488 nm with the theoretical curve derived from LII model [17] (see Fig. 3).…”