Specific Ion Effects on Adsorbed Zwitterionic Copolymers,Macromolecules

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Specific Ion Effects on Adsorbed Zwitterionic Copolymers
Macromolecules ( IF 5.1 ) Pub Date : 2020-11-12 , DOI: 10.1021/acs.macromol.0c01815
Eugenie Jumai’an ₁ , Elena Garcia ₂ , Margarita Herrera-Alonso ₂ , Michael A. Bevan ₁

Affiliation

We report direct measurements of interactions, dimensions, and solution behavior of adsorbed nonionic and zwitterionic triblock copolymers as a function of aqueous [NaCl] and [MgSO₄] in the range 0–1 M. Total internal reflection microscopy is used to measure kT- and nanometer-scale interactions between hydrophobic colloids and surfaces with adsorbed triblock copolymers with central poly(propylene oxide) (PPO) blocks and end blocks of the following: poly(ethylene oxide) (PEO), poly(3-(N-2-methacryloyloxyethyl-N,N-dimethyl) ammonatopropanesulfonate) (PMAPS), and poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC). The findings indicate the following qualitatively different and unique behavior for each polymer: PEO layers are [NaCl]-independent but collapse and become less repulsive and eventually attractive with increasing [MgSO₄]; PMAPS layers are increasingly repulsive and extended with increasing [NaCl] but become less repulsive/extended with increasing [MgSO₄]; and PMPC layers are completely insensitive to both [NaCl] and [MgSO₄]. A competition between solvated molecular interactions and structures appears to explain the unique response of each polymer to nonspecific and specific ion effects as a function of aqueous salt solution composition.

中文翻译：

对吸附的两性离子共聚物的特定离子效应

我们报告的相互作用，尺寸和吸附非离子和两性离子的三嵌段共聚物的溶液行为的直接测量作为水溶液[氯化钠]和[硫酸镁的函数₄ ]在0-1范围内M.全内反射显微术用来测量KT -和疏水胶体与表面吸附的具有中心聚环氧丙烷（PPO）嵌段和以下末端嵌段的三嵌段共聚物之间的纳米级相互作用：聚环氧乙烷（PEO），聚（3-（N -2- methacryloyloxyethyl- ñ，ñ-二甲基）氨基丙烷丙烷磺酸盐）（PMAPS）和聚（2-甲基丙烯酰氧基乙基磷酰胆碱）（PMPC）。这些发现表明每种聚合物在质量上有以下不同和独特的行为：PEO层是[NaCl]独立的，但塌陷并且排斥力变小，并随着[MgSO ₄ ]的增加最终具有吸引力。PMAPS层随着[NaCl]的增加而逐渐排斥和延伸，但随着[MgSO ₄ ]的增加，排斥/延伸程度降低。且PMPC层对[NaCl]和[MgSO ₄ ]都完全不敏感。溶剂化的分子相互作用和结构之间的竞争似乎可以解释每种聚合物对非特异性和特异性离子效应的独特反应，这是盐水溶液组成的函数。

更新日期：2020-11-25

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