Adsorption of anionic polyelectrolytes to dioctadecyldimethylammonium bromide monolayers
Adsorption of anionic polyelectrolytes to dioctadecyldimethylammonium bromide monolayers
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双十八烷基二甲基溴化铵单层对阴离子聚电解质的吸附
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
H. Menzel
中科院分区：
文献类型：
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作者：
J. Engelking;H. Menzel
摘要：以空气/水界面上的双十八烷基二甲基溴化铵（DODA）单层作为带电表面模型，研究阴离子聚电解质的吸附。在纯水表面铺展后，单分子层被压缩，随后采用 Fromherz 技术转移到聚电解质溶液上。通过记录恒定面积下表面压力的变化来监测聚电解质吸附。对于聚（苯乙烯磺酸盐）和羧甲基纤维素，表面压力随时间变化的曲线给出了表明吸附量和表面压力之间的直接相关性以及单独的扩散控制过程的曲线。对于刚性棒状聚(对亚苯基磺酸盐)，情况更为复杂。将表面压力绘制为时间函数会得到一条 S 形曲线，其特征在于诱导期。诱导期可以用域的形成来解释，可以将其视为结晶过程。采用为聚合物结晶开发的 Avrami 表达式，可以描述刚性棒状聚（对亚苯基磺酸盐）吸附时表面压力的变化。
Abstract:Monolayers of dioctadecyldimethylammonium bromide (DODA) at the air/water interface were used as model for charged surfaces to study the adsorption of anionic polyelectrolytes. After spreading on a pure water surface the monolayers were compressed and subsequently transferred onto a polyelectrolyte solution employing the Fromherz technique. The polyelectrolyte adsorption was monitored by recording the changes in surface pressure at constant area. For poly(styrene sulfonate) and carboxymethylcellulose the plot of the surface pressure as function of time gave curves which indicate a direct correlation between the adsorbed amount and surface pressure as well as a solely diffusion controlled process. In the case of rigid rod-like poly(p-phenylene sulfonate)s the situation is more complicated. Plotting the surface pressure as function of time results in a curve with sigmoidal shape, characterized by an induction period. The induction period can be explained by a domain formation, which can be treated like a crystallization process. Employing the Avrami expression developed for polymer crystallization, the change in the surface pressure upon adsorption of rigid rod-like poly(p-phenylene sulfonate)s can be described.