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在变化的表面聚合物相互作用下,通过纳米孔的非单质聚合物转位动力学
Neha Manohar1, Robert A Riggleman1, Daeyeon Lee1
1Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
The Journal of chemical physics
|February 29, 2024
概括
在狭窄的空间中,聚合物转移的动态是复杂的. 吸引表面相互作用最初会加快聚合物运动的速度,但如果吸附发生,可以减缓它的速度,影响聚合物上循环和生物分离应用.
科学领域:
- 聚合物物理 聚合物物理
- 软物质物理学 软物质物理学
- 物理化学 物理化学
背景情况:
- 了解受限环境中的聚合物动态对于聚合物上循环和生物分离等应用至关重要.
- 现有的模型往往简化了表面相互作用,溶解和限制的相互作用.
研究的目的:
- 开发一种使用自相一致的场理论来研究聚合物转位动力学的热屏障模型.
- 调查吸引表面相互作用,排除体积和腔体大小对聚合物转位动态的影响.
主要方法:
- 基于自相一致的场理论的热屏障模型的开发.
- 模拟通过两个腔之间的单段宽度纳米孔的聚合物转移.
- 分析平均转位时间 (τ) 作为表面相互作用强度 (ɛ) 和排除体积 (u0) 的函数.
主要成果:
- 对于高溶剂中的聚合物,观察到平均转位时间与表面相互作用强度的非单调依赖.
- 在低表面吸引力下,排除体积效应占主导地位,增加转位时间.
- 增加的表面吸引力最初通过抵消排斥体积来加速转位,但强大的吸引力导致吸附和显著减缓动力学.
- 吸附过渡点取决于排除的体积强度.
- 转位动力学受到空洞的相对大小的影响,在表面吸引力增加的情况下,更快的转位进入更小的空洞,更慢的转位进入更大的空洞.
结论:
- 表面相互作用在聚合物转位动力学中起着复杂的,非单调的作用.
- 排除体积,表面吸引力和限制之间的平衡决定了转移效率.
- 开发的模型提供了对纳米和微型设备中受控聚合物运输设计系统的见解.
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