Surface Rheology of Monolayers of Triblock Copolymers of PEO and PPO: Surface Light Scattering Studies at the Air/Water Interface
Surface Rheology of Monolayers of Triblock Copolymers of PEO and PPO: Surface Light Scattering Studies at the Air/Water Interface
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PEO 和 PPO 三嵌段共聚物单层的表面流变学：空气/水界面的表面光散射研究
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Hyuk Yu
中科院分区：
文献类型：
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作者：
Chanjoong Kim;Hyuk Yu
在空气/水界面上对聚（环氧乙烷），PEO和聚（环氧丙烷），PPO的三嵌段共聚物单层进行了静态和动态粘弹性研究。这些共聚物以其商品名称Pluronics和Polaxamers而闻名。表面光散射（SLS）技术与Wilhelmy板方法使我们能够探测单层膜的静态和动态粘弹性特性。在7-32℃的温度范围内，研究了不同分子结构的共聚物PEO-PPO-PEO （2.20 kg/mol）和对称共聚物PPO-PEO-PPO （1.95 kg/mol）对表面粘弹性响应的影响。SLS实验表明，在整个温度范围内，弹性贡献主导了两种共聚物的粘弹性行为。此外，相对于单层表面密度，静态弹性和动态粘弹性之间存在明显的对应关系。当从表面压力-表面密度等温线推导出的静态弹性达到最大值时，从SLS推导出的动态弹性和粘度也有相应的行为。
Static and dynamic viscoelastic studies of monolayers of triblock copolymers of poly(ethylene oxide), PEO, and poly(propylene oxide), PPO, are performed at the air/water interface. These copolymers are better known by their trade names of Pluronics and Polaxamers. The technique of surface light scattering (SLS) with the Wilhelmy plate method enables us to probe both static and dynamic viscoelastic properties of the monolayers. The effect of varying the molecular architecture on the surface viscoelastic response is examined with two different copolymers, PEO-PPO-PEO (2.20 kg/mol) and its symmetric counterpart, PPO-PEO-PPO (1.95 kg/mol), over the temperature range 7-32 °C. SLS experiment reveals that the elastic contribution dominates the viscoelastic behavior of both copolymers over the entire temperature range. Further, there is a clear correspondence between the static elasticity and the dynamic viscoelasticity relative to monolayer surface density. When the static elasticity deduced from the surface pressure-surface density isotherm reaches a maximum, the corresponding behavior is observed for the dynamic elasticity and viscosity deduced from SLS.