College of Mechanical Science and Engineering, Jilin University, Changchun 130022, China.
Biomicrofluidics. 2012 Jul 13;6(3):34101. doi: 10.1063/1.4732799. Print 2012 Sep.
A basic understanding of the transport mechanisms of nanostructures in a polymer brush-modified nanochannel as well as the brush-nanostructure interactions at molecular level is important to design and fabricate emerging smart nano/microfluidic channels. In this work, we report coarse-grained molecular dynamics simulations of the translocation of nanoparticles through a cylindrical nanochannel coated with the polymer brush. The effects of the interparticle interaction and grafting density on the distribution and electrokinetic transport of nanoparticles are addressed in detail. Analysis of the distribution and velocity profiles of nanoparticles from the simulations indicate that the location of nanoparticles along the radial direction and their migration velocity are very sensitive to the change of interparticle interaction. We find complicated transport dynamics of nanoparticles under the influence of various grafting densities. The nanoparticles show markedly different translocation behavior upon increasing the grafting density, which depends on the counterion distribution, free room within the brush, nanoparticle-polymer friction, and brush configuration. Our results may serve as a useful starting point for the transport of nanostructures in polymer-modified channels and help to guide the design of novel smart nanofluidic channels for controlling the migration behavior of nanostructures.
对聚合物刷修饰纳米通道中纳米结构的传输机制以及分子水平上的刷-纳米结构相互作用有基本的了解，对于设计和制造新兴的智能纳/微流道至关重要。在这项工作中，我们报告了通过涂覆聚合物刷的圆柱形纳米通道中纳米颗粒迁移的粗粒分子动力学模拟。详细研究了颗粒间相互作用和接枝密度对纳米颗粒分布和电动传输的影响。通过模拟分析纳米颗粒的分布和速度分布表明，纳米颗粒在径向方向上的位置及其迁移速度对颗粒间相互作用的变化非常敏感。我们发现纳米颗粒在各种接枝密度的影响下表现出复杂的传输动力学。随着接枝密度的增加，纳米颗粒表现出明显不同的输运行为，这取决于抗衡离子分布、刷内的自由空间、纳米颗粒-聚合物摩擦和刷的构型。我们的结果可以作为聚合物修饰通道中纳米结构传输的有用起点，并有助于指导新型智能纳流控通道的设计，以控制纳米结构的迁移行为。
