Ferreira Elisabete S C, Voroshylova Iuliia V, Koverga Volodymyr A, Pereira Carlos M, Cordeiro M Natália D S
LAQV@REQUIMTE, Faculdade de Ciências, Departamento de Química e Bioquímica, Universidade do Porto , Rua do Campo Alegre, 4169-007 Porto, Portugal.
CIQ(UP), Faculdade de Ciências, Departamento de Química e Bioquímica, Universidade do Porto , Rua do Campo Alegre, 4169-007 Porto, Portugal.
J Phys Chem B. 2017 Dec 7;121(48):10906-10921. doi: 10.1021/acs.jpcb.7b08251. Epub 2017 Nov 21.
In this work we developed a new force field model (FFM) for propylene glycol (PG) based on the OPLS all-atom potential. The OPLS potential was refined using quantum chemical calculations, taking into account the densities and self-diffusion coefficients. The validation of this new FFM was carried out based on a wide range of physicochemical properties, such as density, enthalpy of vaporization, self-diffusion coefficients, isothermal compressibility, surface tension, and shear viscosity. The molecular dynamics (MD) simulations were performed over a large range of temperatures (293.15-373.15 K). The comparison with other force field models, such as OPLS, CHARMM27, and GAFF, revealed a large improvement of the results, allowing a better agreement with experimental data. Specific structural properties (radial distribution functions, hydrogen bonding and spatial distribution functions) were then analyzed in order to support the adequacy of the proposed FFM. Pure propylene glycol forms a continuous phase, displaying no microstructures. It is shown that the developed FFM gives rise to suitable results not only for pure propylene glycol but also for mixtures by testing its behavior for a 50 mol % aqueous propylene glycol solution. Furthermore, it is demonstrated that the addition of water to the PG phase produces a homogeneous solution and that the hydration interactions prevail over the propylene glycol self-association interactions.
在这项工作中，我们基于OPLS全原子势开发了一种新的丙二醇（PG）力场模型（FFM）。利用量子化学计算对OPLS势进行了优化，并考虑了密度和自扩散系数。基于密度、汽化焓、自扩散系数、等温压缩率、表面张力和剪切粘度等广泛的物理化学性质对这种新的FFM进行了验证。在很宽的温度范围（293.15 - 373.15 K）内进行了分子动力学（MD）模拟。与其他力场模型（如OPLS、CHARMM27和GAFF）的比较表明结果有了很大改进，能更好地与实验数据相符。然后分析了特定的结构性质（径向分布函数、氢键和空间分布函数），以支持所提出的FFM的适用性。纯丙二醇形成连续相，没有微观结构。结果表明，通过测试其在50 mol%丙二醇水溶液中的行为，所开发的FFM不仅对纯丙二醇而且对混合物都能给出合适的结果。此外，还证明了向PG相中加水会产生均匀溶液，并且水合相互作用胜过丙二醇的自缔合相互作用。
