在稀释水溶液中对聚乙烯链的构造产生抗聚电解质和聚电解质效应
Zening Liu1, Jong K Keum1,2, Tianyu Li1
1Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
PNAS nexus
|July 10, 2023
概括
在水中存在的多聚乙烯 (PZs) 采用了卷状结构. 添加盐会导致它们的大小发生意想不到的变化,揭示了复杂的电荷效应和形状.
科学领域:
- 聚合物化学 聚合物化学
- 生物物理化学 生物物理化学
- 材料科学 材料科学 材料科学
背景情况:
- 聚二 (PZs) 是合成聚合物,模仿内在无序的蛋白质.
- 假设PZ在溶液中采用球状或随机的线圈形状.
- 盐对PZ形状的影响还不太清楚.
研究的目的:
- 在水溶液中研究聚硫乙烯甲基酸盐 (PSBMA) 的构造性行为.
- 为了测试有关PZ构成和盐效应的假设.
- 阐明电荷调节和选在PZ行为中的作用.
主要方法:
- 动态光散射 (DLS) 用于测量水力动力半径.
- 微角X射线散射 (SAXS) 用于确定旋转半径.
- 泽塔电位测量,传输电子显微镜 (TEM) 和初始分子动力学 (AIMD) 模拟.
主要成果:
- 即使在几乎没有盐的条件下,PZs也保留了卷状形状,由于质子化而获得净正电荷.
- 添加化 (KBr) 诱导了半径的非单调变化,显示了最初的扩张 (抗聚电解质效应),然后是收缩 (聚电解质效应).
- 与非带电和阴离子聚合物进行比较,突出了PZs的独特行为.
结论:
- 盐在调节多晶子的净电荷和形态状态方面发挥着至关重要的作用.
- 观察到的抗聚电解质和聚电解质效应分别归因于电荷调节和电荷选.
- 这项研究提供了对聚二的溶液行为的关键见解,这与生物材料和药物输送应用相关.
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