Molecular weight dependence of polymersome membrane structure, elasticity, and stability
Molecular weight dependence of polymersome membrane structure, elasticity, and stability
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DOI：
10.1021/ma020669l
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发表时间：
2002-10-08
期刊：
影响因子：
5.5
通讯作者：
Discher, DE
中科院分区：
文献类型：
--
作者：
Bermudez, H;Brannan, AK;Discher, DE
囊泡制备在水中从一系列的二嵌段共聚物-“聚合物囊泡”-的物理特征。随着分子量（M）超过bar（n）的增加，聚（环氧乙烷）-聚丁二烯的自组装双层的疏水核心厚度增加至接近20 nm，这显著大于任何先前研究的脂质或聚合物囊泡系统。囊泡的显微操作显示出界面主导的弹性，其独立于（M）对bar（n）。此外，由最大面积应变定义的膜稳定性随着（M）超过bar（n）而增加，接近由平均场思想预测并由界面张力设定的通用极限。非线性响应和记忆效应也随着（M）在bar（n）上的增加而出现，表明在更高的（M）在bar（n）上的链缠结的开始。结果突出了界面的限制和过渡到自组装体响应。
Vesicles prepared in water from a series of diblock copolymers-"polymersomes"-are physically characterized. With increasing molecular weight (M) over bar (n), the hydrophobic core thickness for self-assembled bilayers of poly(ethylene oxide) - polybutadiene increases up to similar to20 nm, which is considerably greater than any previously studied lipid or polymersome system. Micromanipulation of vesicles demonstrates an interface-dominated elasticity that is independent of (M) over bar (n). Furthermore, membrane stability as defined by the maximal areal strain increases with (M) over bar (n), approaching a universal limit predicted by mean-field ideas and set by the interfacial tension. Nonlinear responses and memory effects also emerge with increasing (M) over bar (n), indicating the onset of chain entanglements at higher (M) over bar (n). The results highlight the interfacial limits and transitions to bulk responses of self-assemblies.