一个蒙特卡洛模拟的标记物扩散在无形聚合物中的模拟
Ali Mansuri1,2, Paras Vora1, Tim Feuerbach3
1Department of Biochemical and Chemical Engineering, TU Dortmund University, 44227 Dortmund, Germany. professors.fsv.bci@tu-dortmund.de.
Soft matter
|July 24, 2024
概括
这项研究使用蒙特卡洛模拟来探索玻璃过渡附近的聚合物中的标记物扩散. 一种新的方法将追踪器等待时间与聚合物旋转时间连接起来,揭示了控制扩散的分数指数.
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
- 统计力学 统计力学
背景情况:
- 在无形聚合物中的标记物扩散对于技术应用至关重要.
- 了解粘度和扩散系数的分离成分数关系是具有挑战性的.
研究的目的:
- 为了研究分数指数对在玻璃过渡附近的聚合物中标志物扩散系数的影响.
- 开发一个模拟框架,将标记物扩散与聚合物动态联系起来.
主要方法:
- 使用3D蒙特卡洛模拟框架.
- 使用连续时间随机步行模型进行标记器扩散.
- 基于聚合物旋转相关时间的计算等待时间分布.
主要成果:
- 建立了一个关系,其中分数指数将追踪器等待时间与聚合物旋转时间联系起来.
- 使用基于摩尔体积的分数指数,与实验扩散度达成合理的协议.
- 在玻璃过渡温度以上的标志物扩散中观察到正常的布朗动力学.
结论:
- 提出的方法有效地将微观动力学 (旋转时间) 与宏观运输 (扩散) 联系起来.
- 分数指数在描述超冷聚合物中的标记物扩散方面发挥着关键作用.
- 模拟结果与实验数据保持一致,验证了方法.
相关概念视频
01:21Polymer Classification: Crystallinity
2.8K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.8K
01:08Molecular Weight of Step-Growth Polymers
2.2K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.2K
01:10Polymers: Molecular Weight Distribution
3.3K
For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
3.3K