EFFECT OF CARBAMIDE ADSORPTION ON THE GROWTH-KINETICS OF THE NH4CL CRYSTALS

This work supplements the adsorption model of 2D-isomorphism proposed earlier for the NH4Cl-CO(NH2)(2) system and reveals the correspondence between the growth rates of the NH4Cl crystals in the presence of car bamide and the co-crystallization of carbamide with ammonium chloride. It follows from the kinetic data that the NH4Cl . CO(NH2)(2) impurity capture becomes significant when the carbamide concentration in solut ion is sufficient for almost monolayer adsorption of the impurity on t he crystal surface and the onset of multilayer adsorption. The concent ration of the guest phase intergrowths falls with the increase in the host crystal growth rate.