Mirzaev S Z, Kaatze U
Heat Physics Department, Uzbekistan Academy of Sciences, Katartal 28, Tashkent, 700135 Uzbekistan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Feb;65(2 Pt 1):021509. doi: 10.1103/PhysRevE.65.021509. Epub 2002 Jan 25.
Between 200 kHz and 130 MHz, the ultrasonic attenuation spectrum of the ionic ethylammonium nitrate--n-octanol mixture of critical composition has been measured at various reduced temperatures (1.5 x 10(-4)<or= t <or=5.7 x 10(-2)). Using static and dynamic light scattering data as well as viscosity and heat capacity data from the literature, the experimental spectra have been evaluated to yield the scaling function, with the background contribution to the spectra as the only adjustable parameter. Agreement, within the limits of experimental error, of the measured scaling function with that of the nonionic binary system ethanol--dodecane and with the theoretical predictions of the Bhattacharjee-Ferrell dynamic scaling model is found. The amplitude of the fluctuation correlation length xi(o) (=0.47 nm) and the amount of the coupling constant /g/ (=1.3) are rather high as compared to nonionic binary critical mixtures. The amplitude of the relaxation rate of order parameter fluctuations Gamma(o)(=2.6 x 10(8) s(-1)) exhibits an unusual small value, likely to the most part a reflection of the high viscosity and thus small diffusion coefficient of the ionic liquid.
在200千赫兹至130兆赫兹之间，已在各种约化温度（1.5×10⁻⁴≤t≤5.7×10⁻²）下测量了临界组成的离子型硝酸乙铵 - 正辛醇混合物的超声衰减谱。利用静态和动态光散射数据以及文献中的粘度和热容数据，对实验谱进行了评估以得出标度函数，将谱的背景贡献作为唯一可调参数。发现在实验误差范围内，测得的标度函数与非离子二元体系乙醇 - 十二烷的标度函数以及Bhattacharjee - Ferrell动态标度模型的理论预测相符。与非离子二元临界混合物相比，涨落关联长度ξ₀（=0.47纳米）的幅度和耦合常数/g/（=1.3）的值相当高。序参量涨落的弛豫率幅度Γ₀（=2.6×10⁸ 秒⁻¹）呈现出异常小的值，这很可能在很大程度上反映了离子液体的高粘度以及由此导致的小扩散系数。
