Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Lab Chip. 2011 Nov 21;11(22):3766-73. doi: 10.1039/c1lc20697d. Epub 2011 Oct 10.
Modeling the transport of solutes through fluidic systems that have adsorbing surfaces is challenging due to the range of length and time scales involved. The components of such systems typically have dimensions from hundreds of nanometres to microns, whereas adsorption of solutes is sensitive to the atomic-scale structure of the solutes and surfaces. Here, we describe an atomic-resolution Brownian dynamics method for modeling the transport of solutes through sticky nanofluidic channels. Our method can fully recreate the results of all-atom molecular dynamics simulations at a fraction of the computational cost of the latter, which makes simulations of micron-size channels at a millisecond time scale possible without losing information about the atomic-scale features of the system. We demonstrate the capability of our method by simulating the rise and fall of solute concentration in sub-micron-long sticky nanochannels, showing that the atomic-scale features of the channels' surfaces have a dramatic effect on the kinetics of solute transport in and out of the channels. We expect our method to find applications in design and optimization of micro and nanofluidic systems for solute-specific transport and to complement existing approaches to modeling lab-on-a-chip devices by providing atomic scale information at a low computational cost.
由于涉及的长度和时间尺度范围广泛，对具有吸附表面的流体系统中溶质传输进行建模具有挑战性。此类系统的组件通常具有从数百纳米到微米的尺寸，而溶质的吸附对溶质和表面的原子尺度结构敏感。在这里，我们描述了一种用于通过粘性纳流道模拟溶质传输的原子分辨率布朗动力学方法。我们的方法可以在后者计算成本的一小部分上完全重现全原子分子动力学模拟的结果，这使得在毫秒时间尺度上模拟微米尺寸的通道成为可能，而不会丢失有关系统原子尺度特征的信息。我们通过模拟亚微米长粘性纳流道中溶质浓度的上升和下降来展示我们方法的能力，表明通道表面的原子尺度特征对溶质进出通道的传输动力学有显著影响。我们预计我们的方法将在用于特定溶质传输的微纳流系统的设计和优化中找到应用，并通过以低计算成本提供原子尺度信息来补充现有的芯片实验室设备建模方法。
