链分子与排斥性分子间力状态方程的一般低密度校正
Thijs van Westen1, Philipp Rehner2, Thijs J H Vlugt3
1Institute of Thermodynamics and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring 9, D-70569 Stuttgart, Germany.
The Journal of chemical physics
|May 15, 2024
概括
我们开发了三种新模型,以准确地描述低密度链分子的热力学. 这些模型扩展了现有的理论,为流体行为和分子相互作用提供了改进的预测.
科学领域:
- 热力学是一种热力学.
- 物理化学 物理化学
- 统计力学 统计力学
背景情况:
- 基于分子的状态方程通常使用平均场近似,对于低密度的链分子来说,这些近似不那么准确.
- 现有的模型不足以捕捉链连接对稀释系统中单体段环境的影响.
研究的目的:
- 开发改进的半经验方法,用于低密度的链分子的热力学描述.
- 为了提高链流体的状态方程的准确性,特别是那些具有排斥性分子间力量的流体.
主要方法:
- 对聚合物的维尔特海姆一阶热力学扰动理论 (TPT1) 的扩展.
- 开发了三种模型:TPT1-v (第二病毒校正),TPT1-y (对相关性进行海尔姆霍尔茨能量贡献) 和TPT-E (直接修改TPT1).
- 使用分子模拟结果验证各种链流体的压力.
主要成果:
- TPT1-v表现出良好的可转移性,但需要第二个病毒系数,通过蒙特卡洛模拟确定.
- TPT1-y实现了与TPT1-v相似的准确性,并且完全具有预测性,只需要链形几何.
- 这三种方法都改进了低密度链分子热力学的标准平均场理论.
结论:
- 开发的半经验方法显著提高了低密度链分子的热力学描述.
- TPT1-y提供了一种可预测和准确的方法来建模链流体热力学.
- 这些模型作为开发更复杂的实体流体状态方程的有价值的参考系统.
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