MUTUAL DIFFUSION-COEFFICIENTS OF WATER PLUS ETHYLENE-GLYCOL AND WATERPLUS GLYCEROL MIXTURES

The experimental technique and mathematical treatment for holographic interferometry, applied for the measurement for mass diffusivity, are described in detail. Experimental results at 25 degrees C are presente d for three mixtures, water + NaCl, water + ethylene glycol, and water + glycerol. The water + NaCl mixture was used as a reference system t o check the accuracy of this method. Measurements were conducted at th ree concentrations within the range 0.00874-0.0699 mass fraction NaCl. The results were compared to literature data and found to be within t he variance of this measuring method. Measurements were conducted for the water + ethylene glycol system within the concentration range 0.02 50-0.950 mass fraction ethylene glycol and within 0.0200-0.800 mass fr action glycerol for the water + glycerol system. Experimental results are compared to literature data where these data are available. The ag reement for both systems are not as good as for the reference system. The mass diffusivity of the water + ethylene glycol system was found t o vary from 11.70 to 3.75 x 10(-10) m(2) s(-1) at a concentration of 0 .0250 and 0.950 mass fraction ethylene glycol, respectively. The corre sponding values for the water + glycerol system varied from 9.28 to 1. 63 x 10(-10) m(2) s(-1) at a concentration of 0.0200 and 0.800 mass fr action glycerol, respectively.