title: Spontaneous volume transition of polyampholyte nanocomposite hydrogels based on pure electrostatic interaction.
abstract: A circular system is employed in this paper to investigate the swelling behaviors of polyampholyte hydrogels; this circular system can effectively eliminate the disturbance of various factors and keep the surrounding environment constant. It is found that there exists a spontaneous volume transition to the collapsed state of polyampholyte hydrogels, which is attributed to the overshooting effect, and the transition can occur repeatedly under certain conditions. (13)C NMR is employed to investigate the swelling behavior of polyampholyte hydrogels. The swelling kinetics of polyampholyte hydrogels under various circular media and various circular runs are also investigated in this paper. All the results suggest that the spontaneous volume transition to the collapsed state of polyampholyte hydrogels is dominated by pure electrostatic interaction between different charges in polymer chains.
authors.affiliation: Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Xu
authors.forename: Jihua
authors.initials: J
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.forename: Yumei
authors.initials: Y
authors.lastname: Yue
authors.forename: Wende
authors.initials: W
authors.lastname: Zhang
authors.forename: Pixin
authors.initials: P
authors.lastname: Wang