Nature of Bonding in Montmorillonite Adsorbates I:Surface Adsorption

It has been shown that organic solutes that do not have groups which are cation exchangeable adsorb on the surface of neutralized montmorillonite and do not (unlike several solvents such as alkanols and water) penetrate to the interior of the crystal. The number of available sites on the surface is of the order 1018-10-19 sites per m.2 of surface area. The number of interior sites available is about 600 times as high. The fact that surface adsorption is the process involved explains in part the fact that such adsorbates are physiologically available when used in pharmaceutical preparations.