Giunta Giuliana, Carbone Paola
School of Chemical Engineering and Analytical Science, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Interface Focus. 2019 Jun 6;9(3):20180074. doi: 10.1098/rsfs.2018.0074. Epub 2019 Apr 19.
Using molecular dynamics simulations, we analysed the polymer dynamics of chains of different molecular weights entrapped at the interface between two immiscible liquids. We showed that on increasing the viscosity of one of the two liquids the dynamic behaviour of the chain changes from a Zimm-like dynamics typical of dilute polymer solutions to a Rouse-like dynamics where hydrodynamic interactions are screened. We observed that when the polymer is in contact with a high viscosity liquid, the number of solvent molecules close to the polymer beads is reduced and ascribed the screening effect to this reduced number of polymer-solvent contacts. For the longest chain simulated, we calculated the distribution of loop length and compared the results with the theoretical distribution developed for solid/liquid interfaces. We showed that the polymer tends to form loops (although flat against the interface) and that the theory works reasonably well also for liquid/liquid interfaces.
通过分子动力学模拟，我们分析了被困在两种不混溶液体界面处不同分子量链的聚合物动力学。我们发现，当两种液体之一的粘度增加时，链的动力学行为从稀聚合物溶液典型的齐默尔（Zimm）型动力学转变为水动力相互作用被屏蔽的劳斯（Rouse）型动力学。我们观察到，当聚合物与高粘度液体接触时，靠近聚合物珠的溶剂分子数量减少，并将这种屏蔽效应归因于聚合物 - 溶剂接触数量的减少。对于模拟的最长链，我们计算了环长度的分布，并将结果与为固/液界面开发的理论分布进行了比较。我们表明，聚合物倾向于形成环（尽管平贴在界面上），并且该理论对于液/液界面也相当适用。
