Organobentonites with Crystalline Layer Separation Used for Adsorption in Water Treatment

Background

Bentonite is a commercial name of a clay belonging to the family of the smectite with a high content of montmorillonite (Giese et al., 2002). The smectite are expandable type 2:1clays. They are shaped by an octagonal aluminum layer between two layers of silica tetrahedra. The forces that maintain the layers joined are relatively weak, where there are interlaminar spaces that expand with the increase in the water content within the inner layers. The cationic hydration between the structural units is a unique property of the smectite type clays. This process depends on the balance between the electrostatic attraction cation-layer and the hydration energy of the cation. When layers of water are interspersed and the separation between the layers increases, the forces that dominate are electrostatic repulsion between layers, which contributes to the process of swelling and can causea complete dissociate among layers.