Xu Li, Kozlovskaya Veronika, Kharlampieva Eugenia, Ankner John F, Sukhishvili Svetlana A
Department of Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030.
ACS Macro Lett. 2011 Nov 30;2012(1):127-130. doi: 10.1021/mz200075x.
We have found diffusion of polyelectrolyte chains within multilayer films to be highly anisotropic, with the preferential chain motion parallel to the substrate. The degree of anisotropy was quantified by a combination of fluorescence recovery after photobleaching and neutron reflectometry, probing chain diffusion in directions parallel and perpendicular to the substrate, respectively. Chain mobility was controlled by ionic strength of annealing solutions and steric hindrance to ionic pairing of interacting polyelectrolytes.
我们发现，聚电解质链在多层膜内的扩散具有高度各向异性，链的优先运动方向与基底平行。通过光漂白后荧光恢复和中子反射率相结合的方法对各向异性程度进行了量化，分别探测了链在平行和垂直于基底方向上的扩散。链的迁移率受退火溶液的离子强度和相互作用的聚电解质离子配对的空间位阻控制。
