Factor of Thermodiffusion of Binary Mixtures Containing Alcohol Vapor

Abstract

UDC 533.735Thermodiffusion separation of the binary mixtures of argon with an ethanol, n-propanol, and iso-propanol vapor and the binary mixtures of ethanol with an n-propanol and iso-propanol vapor has been measured in the temperature range 331-347 K by the two-flask method and the thermodiffusion factor has been determined. The experimental values of the thermodiffusion factor have been compared to the results of calculation according to the Chapman-Enskog theory.Investigation of the temperature dependence of the factor of thermodiffusion of mixtures containing alcohol vapor is of interest from the viewpoint of both obtaining information on intermolecular interactions of substances and using experimental data directly for practical purposes (calculations of technological processes) and scientific developments. In particular, the values of α T of vapor mixtures are required for determination of the critical supersaturation in investigating the process of volume condensation of the vapor [1].The results of measurements of the factor of thermodiffusion of the binary mixtures of argon with the vapor of ethyl (CH 3 CH 2 OH), n-propyl (CH 3 CH 2 CH 2 OH), and iso-propyl ((CH 3 ) 2 CHOH) alcohols that were carried out by us in the temperature range 279.5-325.0 K by the two-flask method have been given in [2]. The mixtures with a low concentration of the alcohol vapor (x 2 = 0.01, 0.03, and 0.05) were investigated with the aim of studying nucleation in the supersaturated vapor by the diffusion-chamber method [1].The present work is a continuation of investigations of the thermodiffusion factor of mixtures containing alcohol vapor. By using the two-flask method [3], here we have extended the temperature range of determination of α T of the Ar-CH 3 CH 2 OH, Ar-CH 3 CH 2 CH 2 OH, and Ar-(CH 3 ) 2 CHOH mixtures with the aim of approaching diffusion-chamber conditions as close as possible. Measurements of the thermodiffusion separation of mixtures of the same composition as those in [2] were carried out at a constant temperature of the cold volume of a thermodiffuser T c = 295 K and with variation of the hot-volume temperature T h from 373 to 413 K. Furthermore, in this work, we have obtained, by the same method, data on the factor of thermodiffusion of the binary mixtures of the vapor of ethyl alcohol with the vapor of n-propyl and iso-propyl alcohols at the same temperatures T c and T h . The molar concentration of the heavycomponent vapor in the mixture was equal to x 2 = 0.3, 0.5, and 0.7 at a total pressure of the mixture in the thermodiffuser of ,0.01⋅10 5 Pa.The binary mixtures were composed at room temperature according to the partial-pressure method. Chemically pure alcohols and pure (A grade) argon (argon content no less than 0.9999) were used as the components. The concentration of the mixture after its separation was analyzed by the katharometric method.The value of the factor of thermodiffusion α T of the binary systems was determined from the relation [4]where x 2 = 1 − x 1 and S is the measured value of the t...

Reference Correlation of the Thermal Conductivity of n-Heptane from the Triple Point to 600 K and up to 250 MPa

“…No obvious systematic trends are observed. The data of Shashkov et al26 show a similar trend to that already observed for their n-hexane data with deviations increasing with increasing temperature. The data of Naziev et al11 are also included only to illustrate the systematic differences observed.The values of the dilute-gas limit thermal conductivity, λ ο (Τ), in mW m À1 K À1 , obtained by the scheme of Eqs.…”

“…From the primary measurements shown in Table 1, only one investigator 11 performed measurements near the dilute-gas limit. To increase the temperature range covered, measurements of five more investigators, 26,31,39,43,47 initially classified as secondary data, were also included. No measurements are ever performed at zero pressure and the values of thermal conductivity are usually obtained by extrapolating the data along an isotherm to a dilute-gas limit.…”

“…In order to develop the correlation, we fitted the effective cross section S λ (nm 2 ), obtained from experimental data, 26,31,39,43,47 weighted by uncertainty, by means of Eq. (3) to a polynomial in inverse temperature, resulting in the following expression: 6, represent the dilute-gas limit thermal conductivity to within 2.4% at the 95% confidence level.…”

Molecular Dynamics Calculation Of Thermodiffusion Coefficients In Binary And Ternary Mixtures

“…The thermodiffusive segregation has been observed and studied in several types of mixtures, viz., gases [5][6][7], electrolytes [8,9], alcohols [10][11][12], polymers [13][14][15], molten metals [16], ferrofluids [17][18][19], semiconductor materials [20][21][22], latex particles [23] and proteins [24,25]. The strength of the Soret effect, as well as its direction is usually determined by a parameter called Soret coefficient, S T (K -1 ) [26].…”

“…It is also relevant in natural processes such as salinity of ocean [146], solar ponds [147] and crude oil stratification in underground oil reservoirs [148][149][150]. This has resulted in scientific investigations involving thermal gradient related transport in gases [6,7], electrolytes [9], alcohols [10,11], ferrofluids [18,19], polymers [13,15], proteins…”