Mass Diffusion Coefficients of Cellulose Acetate Butyrate in Methyl Ethyl Ketone Solutions at Temperatures between (293 and 323) K and Mass Fractions from 0.05 to 0.60 Using the Soret Forced Rayleigh Scattering Method

Abstract

The binary mass diffusion coefficients of cellulose acetate butyrate in methyl ethyl ketone solutions (CAB + MEK) have been measured under atmospheric pressure at temperatures from (293 to 323) K and mass fractions from 0.05 to 0.6. The present experimental apparatus is based on the Soret forced Rayleigh scattering method (S-FRSM), which utilizes the Soret effect to create periodic spatial concentration modulation of micrometer-order fringe spacing in a sample binary liquid mixture due to the absorption of an optical interference grating generated by two intersecting heating laser beams. The decay of the concentration modulation by the mass diffusion process is monitored by the diffraction of a probing laser beam. This method provides several advantages in comparison with conventional techniques such as Taylor dispersion or diaphragm cells; namely, a single measurement can be performed within a short time [(10 -3 to 10 -2 ) s], with small temperature and concentration changes (∆T < 10 -2 K and ∆c < 10 -5 ) using a microliter-order sample volume. To check the reliability of S-FRSM to measure mass diffusion coefficients, the mass diffusion coefficients of toluene + n-hexane, ethanol + benzene, and acetone + carbon tetrachloride were also measured. The expanded (k ) 2) uncertainty in mass diffusion coefficients for CAB + MEK solutions is estimated to be within ( 3.6 %.

Mass Diffusion Coefficient and Soret Coefficient of o-Dichlorobenzene Solutions of PCBM and [60]Fullerene by the Soret Forced Rayleigh Scattering Method

“…In the early works based on this technique, Thyagarajan and Lallemand observed the mass transport in the binary mixtures (CS 2 and ethanol) and determined the thermodiffusion factor α T (the product of Soret coefficient and the temperature) in 1978 . Köhler and his co-workers later improved the TDFRS technique − as the simultaneous measurement method for the diffusion coefficient, the thermodiffusion coefficient, and the Soret coefficient, and they employed this technique for the study of the Soret effect in various systems including liquid mixtures and polymer solutions. , In our laboratory, we constructed the SFRS apparatus for the measurement of the diffusion coefficient in binary mixtures, − applying the forced Rayleigh scattering (FRS) technique to determine the thermal diffusivity in liquids . In the present study, we reconstructed our SFRS apparatus for the measurement of the Soret coefficient.…”

Development of measurement technique of mass diffusion coefficient of aqueous methanol solutions in polymer electrolyte membranes based on infrared Soret forced Rayleigh scattering method using single crystal diamond window in a sample cell

“…The measurement principle of the IR-SFRS technique is basically identical to that of the SFRS technique described in our previous p aper (Niwa et al, 2009). Figure 1 shows the concept of the IR-SFRS technique.…”

“…The intensity of the first order diffracted beam I 1 (t) in the relaxation process of the concentration distribution by the mass diffusion is described as Eq. (2) (Niwa et al, 2009). Fig.…”

“…To contribute to the understanding of the mass transport in PEMs, in our laboratory we have tried to measure the diffusion coefficient in PEMs by the infrared Soret forced Rayleigh scattering (IR-SFRS) method (Sakai et al, 2012), which has been developed to apply the optical holographic grating technique of the Soret forced Rayleigh scattering (SFRS) or the thermal diffusion forced Rayleigh scattering (TDFRS) employing visible light lasers (Hayashida and Nagasaka, 1997;Nagasaka, 2006a, 2006b;Niwa et al, 2009;Matsuura et al, 2015;Matsuura and Nagasaka, 2017;Matsuura and Nagasaka, 2018) to the measurement of solutions in PEMs. The feature of the IR-SFRS technique includes the following: 1) Mass transport in PEMs is induced by a carbon dioxide (CO 2 ) laser without dye for laser absorption, and contactless detection of the mutual diffusion is performed by another laser (probing laser).…”

Decay time control of mass diffusion in a transient grating using a fringe-tunable electrothermal Fresnel mirror

“…For the precise measurement, the threshold value A/B ≥ 10 was introduced (for more detail, see Niwa et al, 2009). The measured time constant agreed well with the Stokes-Einstein equation.…”