Mussel Matan, Horkay Ferenc
Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development , National Institutes of Health, Bethesda , Maryland 20892 , United States.
J Phys Chem Lett. 2019 Dec 19;10(24):7831-7835. doi: 10.1021/acs.jpclett.9b03126. Epub 2019 Dec 5.
Introduction of high valence counterions into polyelectrolyte gels results in a reversible volume phase transition. In the present work new experimental results are reported for the volume transition induced by calcium/sodium exchange in sodium polyacrylate gels. The effects of cross-link density, concentration of ionized groups on the network chains, composition of the equilibrium salt solution containing both mono- and divalent cations, and temperature on the swelling degree of these gels are systematically investigated. It is demonstrated that the normalized swelling data fall on a master curve, indicating that the ion-exchange-induced volume transition exhibits universal behavior in sodium polyacrylate gels. Model calculations made on the basis of the classical Flory-Rehner theory are in reasonable agreement with the measured dependencies.
将高价抗衡离子引入聚电解质凝胶会导致可逆的体积相变。在本工作中,报道了关于聚丙烯酸钠凝胶中钙/钠交换引起的体积转变的新实验结果。系统地研究了交联密度、网络链上离子化基团的浓度、含有单价和二价阳离子的平衡盐溶液的组成以及温度对这些凝胶溶胀度的影响。结果表明,归一化的溶胀数据落在一条主曲线上,这表明离子交换引起的体积转变在聚丙烯酸钠凝胶中表现出普遍行为。基于经典的弗洛里-雷纳理论进行的模型计算与测量的相关性合理吻合。