Hydrogen Bond Network Disruption by Hydration Layers in Water Solutions with Salt and Hydrogen-Bonding Polymers (PEO)

A mean field theory model describing the interactionof ion hydration layers with the network of hydrogen bonds of bothwater and the nonionic polymer poly(ethylene oxide) (PEO) is presented.The predictions of the model for types and statistics of hydrogenbonds, the number of water molecules bound to PEO, or their dependenceon temperature are successfully verified from all-atom simulationsat different NaCl and PEO concentrations. Furthermore, our simulationsshow that the binding of cations to PEO increases monotonically withsalt concentration, in agreement with recent experimental results,through a mechanism in which the sum of the number of bound waterand cations is independent of salt concentration. The model introducedis general and can describe any salt or hydrogen-bond-forming polymer.