Taddese Tseden, Cheung David L, Carbone Paola
School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
School of Chemistry, National University of Ireland Galway, Galway, Ireland.
ACS Macro Lett. 2015 Oct 20;4(10):1089-1093. doi: 10.1021/acsmacrolett.5b00462. Epub 2015 Sep 14.
The dynamics of a polymer chain confined in a soft 2D slit formed by two immiscible liquids is studied by means of molecular dynamics simulations. We show that the scaling behavior of a polymer confined between two liquids does not follow that predicted for polymers adsorbed on solid or soft surfaces such as lipid bilayers. Indeed, our results show that in the diffusive regime the polymer behaves like in bulk solution, following the Zimm model, and with the hydrodynamic interactions dominating its dynamics. Although the presence of the interface does not affect the long-time diffusion properties, it has an influence on the dynamics at short time scale, where for low molecular weight polymers the subdiffusive regime almost disappears. Simulations carried out when the liquid interface is sandwiched between two solid walls show that, when the confinement is a few times larger than the blob size, the Rouse dynamics is recovered.
通过分子动力学模拟研究了限制在由两种不混溶液体形成的软二维狭缝中的聚合物链的动力学。我们表明，限制在两种液体之间的聚合物的标度行为并不遵循吸附在固体或软表面（如脂质双层）上的聚合物所预测的行为。事实上，我们的结果表明，在扩散 regime 中，聚合物的行为类似于本体溶液中的行为，遵循齐姆模型，并且流体动力学相互作用主导其动力学。虽然界面的存在不影响长时间扩散特性，但它在短时间尺度上对动力学有影响，对于低分子量聚合物，亚扩散 regime 几乎消失。当液体界面夹在两个固体壁之间时进行的模拟表明，当限制比 blob 尺寸大几倍时，恢复了劳斯动力学。
