Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstr. 4, 91058 Erlangen, Germany.
Nanoscale. 2017 Nov 23;9(45):17770-17780. doi: 10.1039/c7nr06583c.
Hydrodynamic and thermodynamic non-ideality are important phenomena when studying concentrated and interacting systems in analytical ultracentrifugation (AUC). Here we present an extended Brownian Dynamics (BD) based algorithm which incorporates hydrodynamic and thermodynamic non-ideality. It can serve as an independent and versatile approach for the theoretical description of interparticulate interactions in AUC, as it allows tracking the trajectory of individual particles. Concentration dependencies of the sedimentation and diffusion coefficient have been implemented and validated for the extended BD model. For monodisperse systems, it is shown that profiles obtained by BD are in excellent agreement with well-established Lamm equation solvers. Moreover, important limits and restrictions of current Lamm equation based analysis methods are discussed. In particular, BD allows modeling and evaluation of AUC data of non-ideal polydisperse systems. This is relevant as most nanoparticulate systems are polydisperse in size. Here, a simulation for a polydisperse system including concentration effects is presented for the first time.
在分析超速离心（AUC）中研究浓缩和相互作用体系时，流体动力学和热力学非理想性是重要的现象。在这里，我们提出了一种扩展的基于布朗动力学（BD）的算法，该算法结合了流体动力学和热力学非理想性。它可以作为 AUC 中颗粒间相互作用的理论描述的独立且通用的方法，因为它允许跟踪单个颗粒的轨迹。已经为扩展的 BD 模型实现并验证了沉降和扩散系数的浓度依赖性。对于单分散体系，BD 获得的分布与成熟的 Lamm 方程求解器非常吻合。此外，还讨论了当前基于 Lamm 方程的分析方法的重要限制。特别是，BD 允许对非理想多分散体系的 AUC 数据进行建模和评估。这是相关的，因为大多数纳米颗粒体系在尺寸上是多分散的。这里，首次提出了一个包含浓度效应的多分散体系的模拟。
