Using molecular simulations to probe pore structures and polymer partitioning in size exclusion chromatography.
Using molecular simulations to probe pore structures and polymer partitioning in size exclusion chromatography.
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使用分子模拟来探测尺寸排阻色谱中的孔结构和聚合物分配。
DOI：
10.1016/j.chroma.2018.08.049
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Siepmann,JIlja
中科院分区：
文献类型：
--
作者：
Chen,QileP;Schure,MarkR;Siepmann,JIlja
分子模拟已被广泛地用于理解和预测聚合物在尺寸排除色谱（SEC）中的分配。然而，理想的孔隙模型（如圆柱形、球形和狭缝孔隙）通常用于表示SEC柱中的多孔介质，这导致在描述孔隙的几何形状和大小方面存在显着偏差。在这项工作中，使用模拟方法从单分散球形溶胶颗粒的体心立方、随机和凝胶填充中导出了几个复杂的孔隙模型。这些结构的力学稳定性是基于粒子配位数来确定的。将这些多孔结构的孔径分布与市售的宽孔表面多孔颗粒进行了比较。然后，利用Gibbs系综蒙特卡罗模拟计算了具有复杂孔隙模型的聚合物链的孔隙-体分配系数ksec2。考察了粒径、填料结构和孔隙度对ksec2的影响。此外，结构分析可以深入了解聚合物在孔隙中的构象及其对分配行为的影响。这项研究促进了对SEC柱孔隙结构的理解，并使更准确的预测ksec，减少了孔隙几何结构的模糊性。
Molecular simulations have been extensively utilized to understand and predict the polymer partitioning in size-exclusion chromatography (SEC). However, idealized pore models (e.g., cylindrical, spherical, and slit pores) were often used to represent the porous media in an SEC column, which leads to significant deviations in describing the geometry and the size of the pores. In this work, several complex pore models were derived from body-centered cubic, random, and gel packing of monodisperse spherical sol particles using simulation methodology. The mechanical stabilities of these structures were determined based on particle coordination numbers. Pore size distributions of these porous structures were compared to a commercially available, wide-pore superficially porous particle. Then, Gibbs ensemble Monte Carlo simulations were performed to compute the pore-to-bulk partitioning coefficientKSECof a polymer chain with complex pore models. The effects of particle size, packing structure, and porosity onKSECwere explored. In addition, structural analysis provides insight into the conformation of polymers in the pores and its effect on the partitioning behavior. This study promotes the understanding of pore structures in SEC columns and enables more accurate predictions ofKSECwith less ambiguity in pore geometry.