Henle Mark L, Didonna Brian, Santangelo Christian D, Gopinathan Ajay
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90025, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Sep;78(3 Pt 1):031118. doi: 10.1103/PhysRevE.78.031118. Epub 2008 Sep 15.
Describing the diffusion of particles through crowded, confined environments with which they can interact is of considerable biological and technological interest. Under conditions where the confinement dimensions become comparable to the particle dimensions, steric interactions between particles, as well as particle-wall interactions, will play a crucial role in determining transport properties. To elucidate the effects of these interactions on particle transport, we consider the diffusion and binding of finite-size particles within a channel whose diameter is comparable to the size of the particles. Using a simple lattice model of this process, we calculate the steady-state current and density profiles of both bound and free particles in the channel. We show that the system can exhibit qualitatively different behavior depending on the ratio of the channel width to the particle size. We also perform simulations of this system and find excellent agreement with our analytic results.
描述粒子在拥挤、受限且能与之相互作用的环境中的扩散，具有相当大的生物学和技术意义。在受限尺寸与粒子尺寸相当的条件下，粒子间的空间相互作用以及粒子与壁面的相互作用，在决定输运性质方面将起到关键作用。为阐明这些相互作用对粒子输运的影响，我们考虑有限尺寸粒子在直径与粒子尺寸相当的通道内的扩散和结合。通过使用该过程的一个简单晶格模型，我们计算了通道内束缚粒子和自由粒子的稳态电流和密度分布。我们表明，根据通道宽度与粒子尺寸的比值，系统会表现出定性不同的行为。我们还对该系统进行了模拟，并发现与我们的分析结果非常吻合。
