Institute for Nano- and Microfluidics, Technische Universität Darmstadt, Darmstadt, Germany.
Soft Matter. 2018 Oct 3;14(38):7926-7933. doi: 10.1039/c8sm01246f.
We study the relaxation of surface-tethered polymers in microchannels under moderate confinement (i.e. h ∼ Rg, where h is the channel height and Rg is the radius of gyration of the polymer) by experiments with fluorescence-marked DNA molecules and coupled lattice-Boltzmann/molecular dynamics simulations. The determined scaling exponent suggests that the relaxation is dominated by Zimm-dynamics with significant intra-chain hydrodynamic interactions. The relaxation of the DNA molecules is slower in shallower channels, indicating a pronounced effect of confinement on the longest relaxation time. An experimental correlation is obtained for the longest relaxation time as a function of the molecular contour length and the channel height. Good agreement between the experimental and the simulation results is found.
我们通过荧光标记的 DNA 分子实验和耦合的格子玻尔兹曼/分子动力学模拟研究了中等受限（即 h∼Rg，其中 h 是通道高度，Rg 是聚合物的回转半径）下微通道中表面束缚聚合物的弛豫。确定的标度指数表明，弛豫主要由具有显著链内流体动力学相互作用的 Zimm 动力学主导。DNA 分子在较浅的通道中弛豫较慢，表明受限对最长弛豫时间有明显的影响。获得了最长弛豫时间作为分子轮廓长度和通道高度函数的实验相关性。实验结果与模拟结果吻合良好。
