Effect of layer charge on the intercalation of poly(ethylene oxide) in layered silicates: Implications on nanocomposite polymer electrolytes

The effect of layer charge on the intercalation of poly(ethylene oxide) (PE O) was investigated using a series of reduced-charge montmorillonites and s mectites with varying layer charge. The amount of intercalated polymer init ially increases with layer charge but then decreases. In contrast, the amou nt of water present continuously increases. This water is mostly coordinate d with the gallery cations. When PEO is intercalated, it replaces water mol ecules filling the space between the hydrated exchangeable cations. Molecul ar simulations confirm the experiments and show that the polymer oxygen ato ms do not directly associate with the exchangeable cations, which are mostl y coordinated to water molecules and surface oxygen atoms.