Simulated Osmotic Equation of State for Poly(ethylene Oxide) Solutions Predicts Tension-Induced Phase Separation
Simulated Osmotic Equation of State for Poly(ethylene Oxide) Solutions Predicts Tension-Induced Phase Separation
复制标题
聚环氧乙烷溶液的模拟渗透状态方程预测张力引起的相分离
DOI：
10.1021/acs.macromol.0c02334
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发表时间：
2021
期刊：
影响因子：
5.5
通讯作者：
Milner, Scott T.
中科院分区：
文献类型：
--
作者：
Mkandawire, Wezi D.;Milner, Scott T.
聚环氧乙烷 (PEO) 可溶于水，但其溶解度对温度、压力和应力的变化敏感。值得注意的是，当 PEO 溶液受到强流动时，可能会发生相分离。为了探索这些现象，我们使用分子动力学模拟，通过拉动每条链的末端来检查 PEO 在水溶液中张力下的相行为。同时，我们在链上施加谐波势，导致浓度分布不均匀。我们分析该浓度曲线以获得渗透压与浓度的关系。将此结果与 Flory-Huggins 自由能预测的渗透压进行比较，我们获得了水中 PEO 的 chi 参数 χ，作为体积分数 phi 和链张力的函数。我们观察到随着张力的增加 χ(phi) 增加，随着聚合物体积分数 phi 的增加，χ 适度增加，这与实验观察结果一致。
Poly(ethylene oxide) (PEO) is soluble in water, but its solubility is sensitive to changes in temperature, pressure, and stress. Notably, phase separation can occur when PEO solutions are subjected to strong flow. To explore these phenomena, we use molecular dynamics simulations to examine the phase behavior of PEO under tension in aqueous solution by pulling on the ends of each chain. At the same time, we impose a harmonic potential on the chains, resulting in a nonuniform concentration profile. We analyze this concentration profile to obtain the osmotic pressure versus concentration. Comparing this result to the osmotic pressure prediction from the Flory–Huggins free energy, we obtain the chi parameter χ for PEO in water as a function of volume fraction ϕ and chain tension. We observe an increase in χ(ϕ) as the tension increases and a moderate increase in χ as the polymer volume fraction ϕ increases, consistent with experimental observations.
影响因子：
3
作者：
BAE, YC;SHIM, JJ;PRAUSNITZ, JM
通讯作者：
PRAUSNITZ, JM