Salt-induced polyelectrolyte interdiffusion in multilayered films: A neutron reflectivity study
Salt-induced polyelectrolyte interdiffusion in multilayered films: A neutron reflectivity study
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DOI：
10.1021/ma050072g
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发表时间：
2005-10-04
期刊：
影响因子：
5.5
通讯作者：
Schlenoff, JB
中科院分区：
文献类型：
--
作者：
Jomaa, HW;Schlenoff, JB
聚电解质多层膜由聚（苯乙烯磺酸盐），PSS，和聚（二烯丙基二甲基铵）与定期穿插层的氘代PSS。退火，盐，在此多层膜内的模糊的内部分层，随后使用中子反射计。一个“有限源”的扩散模型拟合的数据以及表明，在一个多层的体积比在表面的迁移速度慢得多。增强的表面迁移率和非线性增加的扩散速率与盐的浓度进行了解释，通过盐掺杂模型，其中相关的短长度的移动交换与反离子（“外来电荷”）掺杂到膜的的反离子络合物暴露于高离子强度的解决方案。
Polyelectrolyte multilayers were constructed from poly(styrenesulfonate), PSS, and poly(diallyldimethylammonium) with regularly interspersed layers of deuterated PSS. Annealing, by salt, of the fuzzy internal layering within this multilayer was followed using neutron reflectometry. A "limited source" diffusion model fit the data well and showed that polyelectrolyte migrates much more slowly within the bulk of a multilayer than at the surface. Enhanced surface mobility and a nonlinear increase in diffusion rate with salt concentration were explained by a salt doping model, where correlated short lengths of polyelectrolyte move by exchange with counterions ("extrinsic charge") doped into the ultrathin film of polyelectrolyte complex on exposure to solutions of high ionic strength.