Oostenbrink Chris, van Gunsteren Wilfred F
Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH-Hönggerberg, Zurich, Switzerland.
Phys Chem Chem Phys. 2005 Jan 7;7(1):53-8. doi: 10.1039/b413167c.
Methane aggregation in water has been studied by simulation for thirteen systems of different sizes and compositions. It was found that favourable cluster formation only occurs after a certain critical cluster size has been reached. The effect of urea on hydrophobic clustering was studied for two urea concentrations. High urea concentrations result in slightly enhanced methane cluster formation, rather than a reduction of the hydrophobic effect. Structural analysis of the Kirkwood-Buff excess coordination and preferential solvation points at a mechanism in which urea pushes the methane into the water, locally increasing methane concentration and hence promoting cluster formation.
通过模拟研究了不同大小和组成的13个系统中甲烷在水中的聚集情况。发现只有在达到一定的临界簇尺寸后才会形成有利的簇。研究了两种尿素浓度下尿素对疏水聚集的影响。高尿素浓度导致甲烷簇形成略有增强，而不是疏水效应的降低。对柯克伍德-布夫过量配位和优先溶剂化点进行结构分析，提出了一种机制，即尿素将甲烷推向水中，局部增加甲烷浓度，从而促进簇的形成。
