Comparative Analysis on Chemical Composition of Bentonite
the clay layers have negative crystal charge which is balanced by exchangeable cations such as Na+, K+, Ca2+ in the interlayer together with water molecules bonded by iondipole forces. The hydration of these inorganic cations causes the clay mineral surface to be hydrophilic (Xi et al., 2007; Banik et al., 2015; Rodriguez et al., 2015).