Legros J C, Gaponenko Y, Mialdun A, Triller T, Hammon A, Bauer C, Köhler W, Shevtsova V
Microgravity Research Center, Université Libre de Bruxelles (ULB), CP-165/62, Av. F.D. Roosevelt, 50, B-1050 Brussels, Belgium.
Phys Chem Chem Phys. 2015 Nov 7;17(41):27713-25. doi: 10.1039/c5cp04745e.
We present a comprehensive experimental study of isothermal Fickian diffusion in the ternary and binary liquid mixtures of water, ethanol, and triethylene glycol over the entire ternary composition space. 21 ternary mixtures inside the composition triangle have been investigated by means of the Taylor dispersion technique and 30 binary mixtures by Taylor dispersion and/or optical beam deflection in a Soret cell. The scalar binary diffusion coefficient has been determined along all three binary boundaries of the composition space and compared with estimations based on the Stokes-Einstein relation using stick or slip boundary conditions. The four elements of the ternary diffusion matrix and the diffusion eigenvalues were determined over a large portion of the composition triangle. The pseudo-binary diffusion coefficients obtained in Taylor dispersion experiments with either one of the two independent concentrations kept constant are comparable to the two diffusion eigenvalues. One of the two off-diagonal elements of the diffusion matrix is of the same order as the diagonal ones and, hence, not negligible, whereas the other one is approximately one order of magnitude smaller. Where available, our results compare well with literature data. The investigated compositions also comprise the five compositions that are scheduled for microgravity experiments in the ESA DCMIX3 project.
我们对水、乙醇和三甘醇的三元及二元液体混合物在整个三元组成空间内的等温菲克扩散进行了全面的实验研究。通过泰勒分散技术研究了组成三角形内的21种三元混合物，并通过泰勒分散和/或索雷特池中光束偏转研究了30种二元混合物。已沿着组成空间的所有三个二元边界确定了标量二元扩散系数，并与基于斯托克斯 - 爱因斯坦关系使用粘性或滑移边界条件的估计值进行了比较。在组成三角形的大部分区域确定了三元扩散矩阵的四个元素和扩散特征值。在泰勒分散实验中，保持两个独立浓度之一不变所获得的伪二元扩散系数与两个扩散特征值相当。扩散矩阵的两个非对角元素之一与对角元素具有相同的量级，因此不可忽略，而另一个大约小一个数量级。在有可用数据的情况下，我们的结果与文献数据比较良好。所研究的组成还包括欧洲航天局DCMIX3项目中计划进行微重力实验的五种组成。
