A hydrogel was prepared by cross-linking poly(4-vinyl phenol) with ethylene glycol diglycidyl ether in
order to examine the ion-specific swelling behavior. The swelling ratios to various kinds of aqueous salt
solutions except for N(CH3)4Cl were almost constant, or the gels remained in a swollen state, up to their
saturated concentrations. This unexpected result was ascribed to stabilization of hydrogen-bonding
hydrations to the phenol OH proton and to the phenol ring (π electrons) by anions and cations, respectively.
The supposed mechanism was supported by ab initio calculations for the corresponding small model systems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.