Nuclear Magnetic Relaxation of Nonuniform Systems

Abstract

The effect of electric ions in water upon the proton magnetic relaxation is discussed. Formulas pertaining to solutions of paramagnetic and nonmagnetic ions are derived. The viscosity factor occurring in the theory for uniform systems has to be replaced by an average of inverse local viscosities weighted by the dimensions of the moving particles or by individual diffusion constants. The concept of mutual viscosity—describing the interaction between two unlike liquid layers—is helpful in correlating the numeric results. The influence of temperature and concentration has been studied experimentally. The behavior of trivalent ions like aluminum can be understood by assuming hydration. The effect of monovalent ions can be explained on the basis of a slightly decreased diffusion constant of the free water molecules. Treated as a two‐phase system, the experimental results enable the evaluation of the average time of adsorption. For aluminum, this is one‐hundredth of a second.