Vögele Martin, Holm Christian, Smiatek Jens
Institute for Computational Physics, University of Stuttgart, Stuttgart, Germany.
J Chem Phys. 2015 Dec 28;143(24):243151. doi: 10.1063/1.4937805.
We present simulations of aqueous polyelectrolyte complexes with new MARTINI models for the charged polymers poly(styrene sulfonate) and poly(diallyldimethylammonium). Our coarse-grained polyelectrolyte models allow us to study large length and long time scales with regard to chemical details and thermodynamic properties. The results are compared to the outcomes of previous atomistic molecular dynamics simulations and verify that electrostatic properties are reproduced by our MARTINI coarse-grained approach with reasonable accuracy. Structural similarity between the atomistic and the coarse-grained results is indicated by a comparison between the pair radial distribution functions and the cumulative number of surrounding particles. Our coarse-grained models are able to quantitatively reproduce previous findings like the correct charge compensation mechanism and a reduced dielectric constant of water. These results can be interpreted as the underlying reason for the stability of polyelectrolyte multilayers and complexes and validate the robustness of the proposed models.
我们用针对带电荷聚合物聚苯乙烯磺酸盐和聚二烯丙基二甲基氯化铵的新MARTINI模型展示了水性聚电解质复合物的模拟。我们的粗粒化聚电解质模型使我们能够在化学细节和热力学性质方面研究大长度和长时间尺度。将结果与之前的原子分子动力学模拟结果进行比较，验证了我们的MARTINI粗粒化方法能够以合理的精度再现静电性质。通过对径向分布函数对和周围粒子累积数的比较，表明了原子级和粗粒化结果之间的结构相似性。我们的粗粒化模型能够定量再现之前的发现，如正确的电荷补偿机制和水的介电常数降低。这些结果可以解释为聚电解质多层膜和复合物稳定性的潜在原因，并验证了所提出模型的稳健性。
