Microstructural analysis of foam by use of NMR R2 dispersion.

摘要: Abstract The spin–spin relaxation rate R2 (=1/T2) in hydrogel foams measured by use of a multiple spin echo sequence is found to be dependent on the time spacing. This property, referred as R2-dispersion, originates large extent from molecular self-diffusion water within internal field gradients that result magnetic susceptibility differences between gel and air phase. Another contribution surface relaxation. Numerical simulations are performed investigate relation foam microstructure (the mean bubble radius standard deviation radius) composition properties (such susceptibilities, diffusion coefficient relaxivity) at one hand R2-dispersion other hand. simulated R2-dispersions agreement with R2-dispersions. By correlating parameters semi-empirical relationship obtained enables size derived curves. R2-derived X-ray micro-CT. illustrates feasibility using 1H measurements determine bubbles alveoli lung tissue.