Fisher Michael E, Aqua Jean-Noël, Banerjee Shubho
Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Lett. 2005 Sep 23;95(13):135701. doi: 10.1103/PhysRevLett.95.135701. Epub 2005 Sep 21.
To understand how multivalency affects criticality in z:1 ionic fluids, we report an ion-cluster association theory embodying ionic solvation and excluded volume for equisized hard-sphere models with z=1-3. In accord with simulation but contradicting integral equation and field theories, the reduced critical temperature falls when z increases while the density rho(c) rises steeply. These trends can be explained semiquantitatively by noting that 80%-90% of the ions near T(c) are bound in neutral or charged clusters, depleting the ionic strength. For z not equal 1, predicted interphase Galvani potentials vanish at T(c).
为了理解多价性如何影响z = 1离子液体中的临界现象，我们报道了一种离子簇缔合理论，该理论体现了具有z = 1 - 3的等尺寸硬球模型的离子溶剂化和排除体积。与模拟结果一致但与积分方程和场论相矛盾的是，当z增加时，约化临界温度下降，而密度ρ(c)急剧上升。通过注意到接近T(c)时80% - 90%的离子结合在中性或带电簇中，从而消耗了离子强度，这些趋势可以得到半定量解释。对于z不等于1的情况，预测的相间伽伐尼电位在T(c)时消失。
