STUDY OF MULTICOMPONENT DIFFUSION INTO POLYCARBONATE RODS USING NMR IMAGING

A proton NMR imaging study has been made of the diffusion of mixtures of acetone and methanol into Bisphenol A polycarbonate. Diffusion of acetone and methanol mixtures was observed for each component individually with the use of deuterated solvents. Fickian diffusion of acetone and methanol mixtures was observed, and separate diffusion coefficients were determined. Spin-spin relaxation times (T2) of the penetrants were obtained across the diffused region as the diffusion process was taking place. These relaxation times were found to be constant for Fickian diffusion in contrast to the gradients in T2 observed for Case II diffusion.