Abstract Inspired by nature, a class of new perspective materials (here referred to as bioclays) can be prepared by combining clay minerals with charged bioorganic moieties. Here we present a comprehensive computational study of a phosphatidylcholine-montmorillonite bioclay composite by employing a series of classical molecular dynamics simulations. Our detailed analysis of the structure and energies of the resulting bioclays reveals that the phosphatidylcholine molecules bind to the montmorillonite surface through their zwitterionic heads, forming layers with the aliphatic tails stretched preferably parallel to the montmorillonite surface. The tails exhibit varying degrees of flexibility and disorder depending on their distance from the surface and density of the surface coverage. The observed detachment of naturally occurring Na+ cations caused by the presence of the phosphatidylcholine zwitterionic heads suggests that cation-exchange is very likely the driving mechanism for the phosphatidylcholine adsorption on montmorillonite. Once the first layer of phosphatidylcholine forms (corresponding to a complete surface saturation, estimated as 0.1 μg cm−2), more molecules can still be attached and stabilized by the mutual phosphatidylcholine intermolecular interactions.

中文翻译：

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通过经典分子动力学模拟磷脂酰胆碱-蒙脱石生物粘土的几何和分子排列

摘要 受大自然的启发，通过将粘土矿物与带电的生物有机基团结合，可以制备一类新的透视材料（这里称为生物粘土）。在这里，我们通过一系列经典的分子动力学模拟，对磷脂酰胆碱-蒙脱石生物粘土复合材料进行了全面的计算研究。我们对所得生物粘土的结构和能量的详细分析表明，磷脂酰胆碱分子通过其两性离子头与蒙脱石表面结合，形成脂肪族尾部优选平行于蒙脱石表面拉伸的层。尾部根据它们与表面的距离和表面覆盖的密度表现出不同程度的柔韧性和无序。观察到的由磷脂酰胆碱两性离子头的存在引起的天然存在的 Na+ 阳离子的脱离表明阳离子交换很可能是磷脂酰胆碱吸附在蒙脱石上的驱动机制。一旦第一层磷脂酰胆碱形成（对应于完全的表面饱和，估计为 0.1 μg cm-2），更多的分子仍然可以通过相互的磷脂酰胆碱分子间相互作用附着和稳定。