Experimental Physics IV and Bayreuth Institute for Macromolecular Research, University of Bayreuth, D-95440, Bayreuth, Germany.
Phys Chem Chem Phys. 2011 Feb 14;13(6):2278-84. doi: 10.1039/c0cp01658f. Epub 2010 Nov 29.
We report a study on particle diffusion in membranes formed from polystyrene-block-poly(2-(dimethylamino)ethyl methacrylate) (PS-b-PDMAEMA) diblock copolymers. The membranes were investigated by scanning electron microscopy and by single-particle tracking employing carboxy-functionalized polystyrene beads loaded with a fluorophore as spectroscopic probes. From the diffusion trajectories we extracted the domain size distribution of the membranes and the local diffusion coefficient of the beads as a function of the size of the beads. The single-particle tracking data revealed that the effective domain sizes of the membranes are reduced with respect to the domain sizes obtained from scanning electron microscopy, reflecting the confined diffusion of the probe particles due to interactions with the domain walls. This is corroborated by a clear correlation between the diffusion coefficient of an individual polystyrene bead and the size of the actual domain to which it is confined.
我们报告了一项关于聚苯乙烯-嵌段-聚（2-二甲氨基乙基甲基丙烯酸酯）（PS-b-PDMAEMA）嵌段共聚物形成的膜中粒子扩散的研究。通过扫描电子显微镜和单粒子跟踪，我们使用带有荧光团的羧基功能化聚苯乙烯珠作为光谱探针研究了这些膜。从扩散轨迹中，我们提取了膜的畴尺寸分布和珠子的局部扩散系数作为珠子尺寸的函数。单粒子跟踪数据表明，与通过扫描电子显微镜获得的畴尺寸相比，膜的有效畴尺寸减小，这反映了由于与畴壁相互作用，探针粒子的受限扩散。这与单个聚苯乙烯珠的扩散系数与它被限制的实际畴的大小之间的明显相关性相吻合。
