Tang Jian, Katashima Takuya, Li Xiang, Mitsukami Yoshiro, Yokoyama Yuki, Chung Ung-Il, Shibayama Mitsuhiro, Sakai Takamasa
Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
The Institute for Solid State Physics, The University of Tokyo, Chiba 227-8581, Japan.
Gels. 2021 Mar 1;7(1):25. doi: 10.3390/gels7010025.
Polyelectrolyte gels exhibit swelling behaviors that are dependent on the external environment. The swelling behaviors of highly charged polyelectrolyte gels can be well explained using the Flory-Rehner model combined with the Gibbs-Donnan effect and Manning's counterion condensation effect (the FRGDM model). This study investigated the swelling properties of a series of model polyelectrolyte gels, namely tetra-polyacrylic acid-polyethylene glycol gels (Tetra-PAA-PEG gels), and determined the applicability of the FRGDM model. The swelling ratio (/) was well reproduced by the FRGDM model in the moderate swelling regime (/ < 10). However, in the high swelling regime (/ > 10), the FRGDM model is approx. 1.6 times larger than the experimental results. When we introduced the finite extensibility to the elastic free energy in the FRGDM model, the swelling behavior was successfully reproduced even in the high swelling regime. Our results reveal that finite extensibility is one of the factors determining the swelling equilibrium of highly charged polyelectrolyte gels. The modified FRGDM model reproduces well the swelling behavior of a wide range of polyelectrolyte gels.
聚电解质凝胶表现出依赖于外部环境的溶胀行为。高电荷聚电解质凝胶的溶胀行为可以通过结合吉布斯-唐南效应和曼宁反离子凝聚效应的弗洛里-雷纳模型（FRGDM模型）得到很好的解释。本研究考察了一系列模型聚电解质凝胶，即四聚丙烯酸-聚乙二醇凝胶（Tetra-PAA-PEG凝胶）的溶胀性能，并确定了FRGDM模型的适用性。在适度溶胀范围（/ < 10）内，FRGDM模型能很好地再现溶胀比（/）。然而，在高溶胀范围（/ > 10）内，FRGDM模型比实验结果大约大1.6倍。当我们在FRGDM模型的弹性自由能中引入有限可扩展性时，即使在高溶胀范围内也能成功再现溶胀行为。我们的结果表明，有限可扩展性是决定高电荷聚电解质凝胶溶胀平衡的因素之一。修正后的FRGDM模型能很好地再现各种聚电解质凝胶的溶胀行为。
