Solutions and Condensed Phases of PEG2000 from All-Atom Molecular Dynamics.
Solutions and Condensed Phases of PEG2000 from All-Atom Molecular Dynamics.
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全原子分子动力学的 PEG2000 溶液和凝聚相。
DOI：
10.1021/acs.jpcb.1c06397
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Blaisten-Barojas,Estela
中科院分区：
文献类型：
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作者：
Sponseller,Daniel;Blaisten-Barojas,Estela
广泛的全原子分子动力学研究聚乙二醇（PEG 2000）溶剂化时，在聚合物本体凝聚相进行了在很宽的温度范围内。我们提出了两种改进的全原子力场，并观察了PEG 2000大分子在水、含4%乙醇的水和乙酸乙酯中溶剂化时的命运。在水溶液中，大分子坍塌成一个长球形的球状结构，而在乙酸乙酯中采用一个相当细长的卷曲结构。在150-340 K温度范围内对聚合物凝聚相的检查使得能够在低于230 K <Tg< 250 K的玻璃化转变温度下对固体玻璃进行原子视图，并且在高于Tg的温度下对橡胶行为进行原子视图。预测的性能包括焓，密度，和内聚能温度行为，比热，热膨胀系数，热压缩系数，体积模量，和Hildebrand溶解度参数低于和高于Tg。在聚合物基质中，PEG 2000大分子缠结在一起，显示出从玻璃相转变为橡胶相时持续存在的宽尺寸分布。计算的属性同意非常好的实验时，可用或立场作为关键的预测，而等待实验测量。了解这种有用的聚合物的热力学和结构，可以有效地预测其在构建纳米医学和纳米治疗的新型复合材料时的行为。
Extensive all-atom molecular dynamics studies of polyethylene glycol (PEG2000) when solvated and in the polymer bulk condensed phases were performed across a wide temperature range. We proposed two modified all-atom force field and observed the fate of the PEG2000macromolecule when solvated in water, water with 4% ethanol, and ethyl acetate. In aqueous solutions, the macromolecule collapsed into a prolate spheroidal ball-like structure while adopting a rather elongated coiled structure in ethyl acetate. Inspection of the polymer-condensed phases across the 150–340 K temperature range enabled the atomistic view of the solid glass below the glass transition temperature of 230 K <Tg< 250 K and the rubber behavior aboveTg. Predicted properties include the enthalpy, density, and cohesive energy temperature behavior, the specific heat, thermal expansivity, thermal compressibility, bulk modulus, and Hildebrand solubility parameter both below and aboveTg. Within the polymer matrix, the PEG2000macromolecules were entangled displaying a wide distribution of sizes that persisted when transitioning from the glass to the rubbery phases. Calculated properties agree very well with experiments when available or stand as crucial predictions while awaiting experimental measurement. Understanding the thermodynamics and structure of this useful polymer enables the efficient prediction of its behavior when building novel composite materials for nanomedicine and nanotherapeutics.