Schulz Benjamin, Mazza Marco G, Bahr Christian
Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Fassberg 17, D-37077 Göttingen, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Oct;90(4):040501. doi: 10.1103/PhysRevE.90.040501. Epub 2014 Oct 7.
We present a study of the molecular diffusion in freely suspended smectic-A liquid crystal films with thicknesses ranging from 20 down to only two molecular layers. The molecular mobility is directly probed by determining the trajectories of single, fluorescent tracer molecules. We demonstrate, using several different smectic compounds, that a monotonic increase of the diffusion coefficient with decreasing film thickness is a general phenomenon. In two-layer films, the diffusion is enhanced by a factor of 3 to 5 compared to the corresponding bulk smectic phase. Molecular dynamics simulations of freely suspended smectic films are presented which support the experimental results.
我们展示了一项关于自由悬浮的近晶A液晶薄膜中分子扩散的研究，这些薄膜的厚度范围从20层到仅两层分子层。通过确定单个荧光示踪分子的轨迹直接探测分子迁移率。我们使用几种不同的近晶化合物证明，扩散系数随薄膜厚度减小而单调增加是一种普遍现象。在两层薄膜中，与相应的块状近晶相相比，扩散增强了3至5倍。还给出了自由悬浮近晶薄膜的分子动力学模拟，其支持了实验结果。
