Infrared study of water adsorbed on Wyoming bentonite

Abstract

Infrared data for Na-Wyoming bentonite showed that the clay-ion system influenced the bending vibration for the water molecules as well as the amount of hydrogen bonds formed. The effects were very pronounced at low water concentrations. When the amount of water adsorbed on the clay surfaces corresponded to a monolayer between the silicate layers, optimum restrictions upon the bending vibrations were found. The amount of hydrogen bonding was also at a maximum here. The amount of hydrogen bonding was at a minimum for a water content corresponding to about two water-layers. As the water content was increased above this value, there was a gradual increase in hydrogen bonding, and a decrease in bending vibration restrictions until the values for bulk water were reached. These results were explained in terms of water-ion and water-surface interactions.