Neitzel Angelika E, Fang Yan N, Yu Boyuan, Rumyantsev Artem M, de Pablo Juan J, Tirrell Matthew V
Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States.
Argonne National Laboratory, Materials Science Division, Lemont, Illinois 60439, United States.
Macromolecules. 2021 Jul 27;54(14):6878-6890. doi: 10.1021/acs.macromol.1c00703. Epub 2021 Jul 6.
Polyelectrolyte complex coacervates of homologous (co)polyelectrolytes with a near-ideally random distribution of a charged and neutral ethylene oxide comonomer were synthesized. The unique platform provided by these building blocks enabled an investigation of the phase behavior across charge fractions 0.10 ≤ ≤ 1.0. Experimental phase diagrams for = 0.30-1.0 were obtained from thermogravimetric analysis of complex and supernatant phases and contrasted with molecular dynamics simulations and theoretical scaling laws. At intermediate to high , a dependence of polymer weight fraction in the salt-free coacervate phase ( ) of ∼ was extracted; this trend was in good agreement with accompanying simulation predictions. Below = 0.50, was found to decrease more dramatically, qualitatively in line with theory and simulations predicting an exponent of 2/3 at ≤ 0.25. Preferential salt partitioning to either coacervate or supernatant was found to be dictated by the chemistry of the constituent (co)polyelectrolytes.
合成了具有近乎理想随机分布的带电和中性环氧乙烷共聚单体的同源（共）聚电解质的聚电解质复合凝聚层。这些构建单元提供的独特平台使得能够研究电荷分数在0.10≤χ≤1.0范围内的相行为。通过对复合相和上清液相的热重分析获得了χ = 0.30 - 1.0的实验相图，并与分子动力学模拟和理论标度律进行了对比。在中等至高χ值时，提取了无盐凝聚层相中聚合物重量分数（φ）对χ的依赖性，即φ∼χ；这一趋势与伴随的模拟预测非常吻合。在χ < 0.50时，发现φ下降得更为显著，定性上与理论和模拟结果一致，即在χ≤0.25时预测指数为2/3。发现优先盐分配到凝聚层或上清液是由组成（共）聚电解质的化学性质决定的。
