固体 - 液体 - 溶液阶段在多 (diallyldimethylammonium) /多 (acrylic acid) 多电解质复合物中在不同温度下.
Chikaodinaka I Eneh1, Kevin Nixon1, Suvesh Manoj Lalwani1
1Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States.
Macromolecules
|March 18, 2024
概括
温度显著影响多电解质复合物 (PECs),影响其相位行为. 这项研究表明,不同的PEC相表现出不同的上临界溶液温度 (UCST),沉物由于动力捕获而显示出更高的UCST.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 多电解质复合物 (PEC) 是由相反电荷的聚合物形成的,其相位行为受到各种因素的影响.
- 温度在PEC相位过渡中的作用经常被忽视,尽管它有可能通过关键溶液行为诱导相位分离.
- 像结合这样的二次相互作用可以进一步复杂化PECs的温度反应.
研究的目的:
- 在不同的条件下研究聚二甲基/聚烯酸 (PDADMA/PAA) 复合物的相位行为.
- 为了确定温度对PDADMA/PAA PECs不同相位状态的影响.
- 阐明初始PEC相位状态与其温度依赖的相位过渡之间的关系.
主要方法:
- 用于制备具有可控离子强度,混合比率和固定pH的PDADMA/PAA复合物.
- 可变温度光学显微镜用于观察相位过渡.
- 全原子分子动力学 (MD) 模拟以调查沉物的行为.
主要成果:
- 在室温下,PDADMA/PAA PEC 呈现出四个不同的阶段:沉物,共存沉物和凝聚物,固体状凝物和凝聚物.
- 确定了过渡到溶液状态的上临界溶液温度 (UCST),与初始阶段有显著差异.
- 与其他阶段相比,固态沉物显示出更高的UCST值.
结论:
- 温度是影响多电解质复合物的相位行为的一个关键因素.
- 一个PEC的初始相位状态,特别是沉物,会由于动力捕捉等现象而影响其热反应.
- 了解温度依赖的相位行为对于刺激响应材料,无膜有机体和分离技术的应用至关重要.
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