The Effect of Short-Range Hydrogen-Bonded Interactions on the Nature of the Critical Point of Ionic Fluids. Part II: Static and Dynamic Light Scattering on Solutions of Ethylammonium Nitrate in n-Octanol
The Effect of Short-Range Hydrogen-Bonded Interactions on the Nature of the Critical Point of Ionic Fluids. Part II: Static and Dynamic Light Scattering on Solutions of Ethylammonium Nitrate in n-Octanol
复制标题
短程氢键相互作用对离子流体临界点性质的影响。
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
H. Weingärtner
中科院分区：
文献类型：
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作者：
W. Schröer;S. Wiegand;H. Weingärtner
我们报道了离子液体近临界涨落的静态和动态光散射测量。该体系为溶解在正辛醇中的硝酸乙基铵，在富盐区发生液-液相变，其上临界点在315K附近，摩尔分数x_1=0.773。在类伊辛临界点对应的温度下，关联长度和散射强度随温度变化。这与以前观察到的电解液体系的平均场行为不同，电解液体系的液-液相变是由长程库仑相互作用驱动的。考虑到a)具有长程和短程性质的分子间相互作用的竞争，以及b)Landau-Ginzburg理论预测的从平均场到伊辛行为的交叉的可能性，对这种差异进行了合理化。
We report on static and dynamic light scattering measurements of near-critical fluctuations of an ionic liquid. The system is ethylammonium nitrate (EAN) dissolved in n-octanol which exhibits a liquid-liquid phase transition in the salt rich regime with an upper critical point near 315 K at a mole fraction of the salt x1 = 0.773. The correlation lengths and scattering intensities scale with temperature corresponding to an Ising-like critical point. This contrasts with previous observations of mean-field behaviour in electrolyte systems with liquid-liquid phase transitions driven by long-range Coulombic interactions. Rationalizations of this discrepancy are offered taking into account a) the competition of intermolecular interactions with long-range and short-range character and b) the possibility of crossover from mean-field to Ising behaviour as predicted by the Landau-Ginzburg theory.