Relaxation Times of Solid-like Polyelectrolyte Complexes of Varying pH and Water Content
Relaxation Times of Solid-like Polyelectrolyte Complexes of Varying pH and Water Content
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DOI：
10.1021/acs.macromol.1c00940
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发表时间：
2021-09-01
期刊：
影响因子：
5.5
通讯作者：
Lutkenhaus, Jodie L.
中科院分区：
文献类型：
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作者：
Lalwani, Suvesh M.;Batys, Piotr;Lutkenhaus, Jodie L.
络合pH值和水的弛豫时间和动力学的聚乙烯（PE）复合物（佩奇）和凝聚的影响仍然知之甚少。在这里，我们描述的动态力学行为的固体状佩奇含有弱PE聚（烯丙胺盐酸盐）（PAH）和聚（丙烯酸）（PAA）在不同的络合pH值，相对湿度和温度与支持分子动力学模拟。时间-温度，时间-水，和时间-固有离子对叠加原理被应用到获得弛豫时间。结果表明，水合PAH/PAA佩奇的弛豫时间的自然对数与水的体积分数成反比（对于给定的络合pH值，lntau类似于phi（-1）（w））。对于检查的所有络合pH值，当相对于固有离子对与水分子的数目的比率（ln（τ）类似于n）绘制时（本征离子对）/n（水））。两者合计，这表明，固体样的，水合PAH/PAA佩奇的松弛是由固有离子对的结合水介导的。
The effect of complexation pH and water on the relaxation time and dynamics of polyelectrolyte (PE) complexes (PECs) and coacervates remains poorly understood. Here, we describe the dynamic mechanical behavior of solid-like PECs containing weak PEs poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) at varying complexation pH, relative humidity, and temperature with support from molecular dynamics simulations. Time-temperature, time-water, and time-intrinsic ion pair superposition principles are applied to obtain the relaxation times. It is shown that the natural log of relaxation time in hydrated PAH/PAA PECs is inversely proportional to the volume fraction of water (ln tau similar to phi(-1)(w)) for a given complexation pH. For all complexation pH values examined, the natural log of relaxation time collapsed into a single line when plotted against the ratio of the number of intrinsic ion pairs to water molecules (ln (tau) similar to n(intrinsic ion pairs)/n(water)). Taken together, this suggests that the relaxation of solid-like, hydrated PAH/PAA PECs is mediated by bound water at the intrinsic ion pair.