On the determination of domain sizes in polymers by spin diffusion

In this article, a mathematical description of spin diffusion in copolymers is presented that avoids some of the approximations employed by previous authors. The analytical relations obtained can readily be used in solid-state NMR experiments to determine the domain size of each component. A numerical approach to spin diffusion has also been examined and its performance has been compared with the analytical method. For systems with interphase structure, the spin diffusion process has been numerically simulated based on a simple model with linear character changes. Application of the present method to systems with or without interphase has been demonstrated. (C) 1996 American Institute of Physics.