Optical Constants in the Infrared for Aqueous Solutions of NaCl†

Querry, Marvin R.; Waring, Richard C.; Holland, Wayne E.; Hale, George M.; Nijm, William P.

doi:10.1364/josa.62.000849

Cited by 52 publications

(35 citation statements)

References 12 publications

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“…Table A1. A similar procedure was used to extract the absorption from the extinction spectra of the aerosols at high relative humidity. In these cases the complex index of refraction for either 3 M or 5 M NaC1 [Querry et al, 1972] was used. A calculated extinction spectrum for given values of d and s r was fit to the experimental spectrum over the range 5000-1300 cm -• by adjusting Dpart and b (Figure 4, curve B).…”

Section: Resultsmentioning

confidence: 99%

“…The water signature is also inconsistent with adsorption on single crystal NaCl(100) under arid conditions, as shown in Figure 6. At any relative humidity the NaC1 aerosol OH-stretching frequency is indistinguishable from that of concentrated NaC1 solutions [Querry et al, 1972]. On the basis of these lines of reasoning we may reject structure II in Figure 1 as a model for the NaC1 particles below 44% RH.…”

Section: Structure Of Naci Particlesmentioning

confidence: 90%

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Water content and morphology of sodium chloride aerosol particles

Weis¹,

Ewing²

1999

J. Geophys. Res.

149

161

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Abstract. Sodium chloride droplets with a median diameter of --•0.4/•m were generated in the laboratory by atomizing an aqueous solution of NaC1 under ambient conditions. Infrared extinction spectra of the aerosols under controlled relative humidity (RH) ranging from 15 to 95% were obtained. The extinction spectra contained both scattering and absorption components. In order to obtain an absorption spectrum of the condensed phase H20 associated with the particulates, it was necessary to subtract from the extinction spectra the absorption by H20 vapor and the scattering by the particulates. H20 vapor subtraction was accomplished by a standard technique. A procedure using Mie theory to subtract the scattering component of the extinction spectrum is described. The absorption spectra were used to determine the water content and structure of the particulates. Above -50% RH the aerosols contain aqueous droplets that have not reached equilibrium with the water vapor during the timescale of the experiments (-10 s). There is a sharp transition in water content at around 50% RH which is consistent with other measures of the recrystallization point. Below 50% RH the NaC1 particles contain an anomalously large amount of H20. Several different particle models are considered to explain the H20 content. The model in which the NaC1 particles contain pockets of aqueous NaC1 solution was found to be most consistent with the spectroscopic observations. The relevance of salt particle morphology and water content to atmospheric aerosol chemistry is discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Structure Of Naci Particlesmentioning

confidence: 90%

Water content and morphology of sodium chloride aerosol particles

Weis¹,

Ewing²

1999

J. Geophys. Res.

149

161

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“…9 By expressing the partial molal quantities in power series, 7 the integrals in Eq. (10) reduces to the following series: (12) am' 21 n=1…”

Section: Theorymentioning

confidence: 99%

Laser heating of an aqueous aerosol particle

Sageev

Seinfeld

1984

Appl. Opt.

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Approximate analytical and full numerical solutions are obtained for the transient response of both a pure water and solution droplets to both short-and long-time laser heating. The differences in the temperature and size histories between pure water and solution droplets are elucidated. The validity of of the approximate analytical solution, extended from that of Armstrong ["Aerosol Heating and Vaporization by Pulsed Light Beams," Appl. Opt. 23, 148 (1984)] in pure water droplets, is evaluated by comparison to solution of the full governing equations.

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“…The procedure for measuring the relative reflectance spectra of the natural water samples was identical to that used during our investigations of NaC1 in water [Querry et al, 1972]. Relative reflectance R+ is defined as R+ = R+s/R+w, where the subscript plus denotes radiant flux linearly polarized with the electric field vector perpendicular to the plane of incidence and R+s and R+w denote absolute specular reflectance of the natural water sample and the distilled water, respectively.…”

Section: Relative Reflectance Spectramentioning

confidence: 99%

Relative reflectance and complex refractive index in the infrared for saline environmental waters

Querry¹,

Holland²,

Waring³

et al. 1977

J. Geophys. Res.

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By using distilled water as the standard reflector, relative specular reflectance spectra in the 2-to 20-urn wavelength region of the infrared were measured for surface water samples collected from the San Francisco Bay, the Pacific Ocean, the Atlantic Ocean, the Great Salt Lake (Utah), the Dead Sea (Israel), and an effluent pit of a phosphate mine in central Florida. Phase difference spectra and spectral values of the complex refractive index were computed for each water sample by applying a Kramers-Kronig analysis to the relative reflectance spectra. Spectral values for the complex refractive index suitable for M ie scattering calculations were tabulated for each water sample. The reflectance spectra of the natural saline waters bore great similarity to spectra for individual aqueous solutions containing NaCI, K2SO4, NH4H2POn, NaNO3, and NaHCO3. Chemical analyses of the water samples are also presented in tabular form. INTRODUCTIONThe complex refractive index is denoted by 1½ = n + ik, where the caret denotes a complex number, n is the index of refraction, k is the extinction coefficient, and i represents the square root of minus one. A quantitative knowledge of spectral values of/• for natural waters is presently of considerable interest to many scientists. Such knowledge has application to (1) computer simulations of the transport of electromagnetic radiation through hydrosols, aerosols, and maritime fogs, (2) theoretical investigations of the energy and hydrological balance of the earth's lakes, oceans, and atmosphere, (3) remote sensing of the chemical quality of environmental waters [Querry, 1975], and (4) solar energy development [Chappell and White, 1976]. Querry et al. [1972, 1974, 1976] previously reported measurements of the relative reflectance spectra in the 2-to 20-tzm wavelength region of the infrared for individual aqueous solutions prepared with distilled water in the laboratory. The solutions contained NaC1, H2SO4, K2SO4, NH•H2PO•, NaNOa, or NailCOs. Kramers-Kronig phase shift dispersion analysis of the reflectance spectra for those solutions provided spectral values for N. We observed that mortatomic ions such as Na +, Cl-, and K + perturbed the intramolecular and intermolecular bonds of the liquid water substances so that corresponding wavelength positions of infrared active fundamental vibrational and librational (lattice vibrational) modes were moderately shifted•to shorter and longer wavelengths, respectively. We also explicitly identified 21 infrared active vibrational modes associated with SO• -•, NH4 +, HSO4-, HaO +, HePO4-, NOs-, HCOa-, or H•O. The half width F, central spectral position of each mode X, mode (band) strength So, and maximum value of k were tabulated for each of the 21 modes. These parameters are presented collectively for the first time in Table 1. Band strengths were evaluated by use of Sot =at -• ft, Akt dv (1) where at (in moles per liter) was the molecular density of the ith constituent in the solution, Akt was the part of k due to a Paper number 6C0904. fundamental...

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Optical Constants in the Infrared for Aqueous Solutions of NaCl†

Cited by 52 publications

References 12 publications

Water content and morphology of sodium chloride aerosol particles

Water content and morphology of sodium chloride aerosol particles

Laser heating of an aqueous aerosol particle

Relative reflectance and complex refractive index in the infrared for saline environmental waters

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