在空气-水界面上,对-和多基基物质 (PFAS) 表面活性剂的结构,方向和动态:分子层面的洞察力
Aditya Choudhary1, Aashish Tsunduru1, Marina Tsianou2
1Department of Materials Science & Engineering, University of Utah, 122 S. Central Campus Drive, Room 304, Salt Lake City, UT 84112, USA.
Journal of colloid and interface science
|October 19, 2024
概括
短链和多基基物质 (PFAS) 更有效地降低表面张力,但需要更高的度. 分子结构决定了PFAS在空气-水界面上的行为,影响了它们的环境命运.
科学领域:
- 环境化学环境化学
- 表面科学是一门学科.
- 计算化学的计算化学
背景情况:
- 和多基基物质 (PFAS) 是持久的环境污染物.
- 了解PFAS在空气水界面的行为对于评估它们的环境命运和开发更安全的替代品至关重要.
- 接口特性受到分子结构,化学和度的影响.
研究的目的:
- 为了研究PFAS在空气-水界面上的分离的分子级细节.
- 为了比较不同的PFAS表面活性剂的界面行为,具有不同的链长和结构.
- 阐明影响PFAS的关联因素,降低表面张力和界面移动性的因素.
主要方法:
- 使用了原子学分子动力学模拟.
- 模拟了三种代表性的PFAS表面活性剂: perfluorooctanoate (PFOA), perfluorobutanoate (PFBA) 和GenX. 这三种表面活性剂的模型.
- 模拟系统地比较PFAS行为作为表面覆盖面的函数.
主要成果:
- 较短链的PFAS (GenX,PFBA) 在较低的表面覆盖率下实现更大的表面张力降低,而不是较长链的PFOA.
- 由于水溶性更高,等效的表面覆盖需要更高的GenX和PFBA散装度.
- 在界面上的PFAS分子方向和移动性强烈依赖于碳尾巴的长度和结构.
- 在高表面度下,在头组附近观察到水二极体的显著排序.
- 接口特性与PFAS-PFAS,PFAS-对应物和PFAS-水相互作用直接相关.
结论:
- PFAS的分子结构显著影响了它们的界面行为和降低表面紧张的有效性.
- 这些发现提供了关于PFAS环境运输和命运的见解.
- 这项研究有助于设计具有减少环境影响的替代化学品.
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