Fukuto M, Ocko B M, Bonthuis D J, Netz R R, Steinrück H-G, Pontoni D, Kuzmenko I, Haddad J, Deutsch M
Condensed Matter Physics and Materials Sciences Department and NSLS II, Brookhaven National Laboratory, Upton, New York 11973, USA.
Rudolf Peierls Centre for Theoretical Physics, Oxford University, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
Phys Rev Lett. 2016 Dec 16;117(25):256102. doi: 10.1103/PhysRevLett.117.256102. Epub 2016 Dec 15.
X-ray reflectivity (XR) and atomistic molecular dynamics (MD) simulations, carried out to determine the structure of the oil-water interface, provide new insight into the simplest liquid-liquid interface. For several oils (hexane, dodecane, and hexadecane) the XR shows very good agreement with a monotonic interface-normal electron density profile (EDP) broadened only by capillary waves. Similar agreement is also found for an EDP including a sub-Å thick electron depletion layer separating the oil and the water. The XR and MD derived depletions are much smaller than reported for the interface between solid-supported hydrophobic monolayers and water.
为确定油水界面的结构而进行的X射线反射率（XR）和原子分子动力学（MD）模拟，为最简单的液-液界面提供了新的见解。对于几种油（己烷、十二烷和十六烷），XR显示与仅由毛细波展宽的单调界面法向电子密度分布（EDP）非常吻合。对于包含一个分隔油和水的亚埃厚电子耗尽层的EDP，也发现了类似的吻合情况。XR和MD得出的耗尽层比固体支撑疏水单分子层与水之间的界面所报道的要小得多。
