CAS Key Laboratory of Soft Matter Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, 230026, P. R. China.
Macromol Rapid Commun. 2019 Feb;40(4):e1800691. doi: 10.1002/marc.201800691. Epub 2018 Nov 22.
Polyion complex (PIC) hydrogels formed by charge attraction of opposite charged polymers have received unique research interest. Their conventional preparation method, with a large amount of residual salt after polymerization, requires a long-term dialysis treatment to remove the salt and toughen the gel. Here, a promising strategy for the one-step preparation of tough PIC hydrogels without dialysis after polymerization is provided. Bicarbonate and proton ions are selected as the counter ions of the cationic monomer and anionic polymers, respectively. By a CO -generating reaction between the counter ions, the residual salt is removed before polymerization, and thus, a PIC hydrogel with tough mechanical performance can be obtained instantly without dialysis. Due to the absence of dialysis, the tough hydrogel can be formed with a wide range of ratios for the oppositely charged polymer with distinct swelling behaviors from non-swelling to super-swelling. This tunable swelling behavior shows the possibility for shape-morphing systems from this one-step method.
聚离子复合物（PIC）水凝胶是通过带相反电荷的聚合物之间的电荷吸引形成的，受到了独特的研究关注。它们的传统制备方法在聚合后会残留大量盐，需要进行长时间的透析处理以去除盐并增强凝胶的韧性。在这里，提供了一种有前途的策略，可以一步制备出聚合后无需透析即可得到坚韧的 PIC 水凝胶。碳酸氢根和质子离子分别被选为阳离子单体和阴离子聚合物的抗衡离子。通过抗衡离子之间的 CO 2 生成反应，在聚合前去除残留盐，因此可以立即获得具有坚韧机械性能的 PIC 水凝胶，而无需透析。由于无需透析，因此可以使用广泛的比例形成带相反电荷的聚合物来制备坚韧的水凝胶，其溶胀行为从不溶胀到超溶胀各不相同。这种可调的溶胀行为表明了从一步法制备形状记忆系统的可能性。
