Nuclear Magnetic Resonance Spectroscopy for the Analysis of Soft Materials

Abstract

1H pulsed NMR is a technique for measuring spin-spin relaxation (transverse relaxation) and spin-lattice relaxation (longitudinal relaxation). Analysis of transverse relaxation decay using Weibull function provides the time constant (spin-spin relaxation time; T2) and shape parameter (Weibull coefficient; W). The T2 and W value correlate with molecular mobility and its distribution, respectively. When the material is composed of multiple components,decay of the total is observed as a superposition decay of each component. The fraction (F) of each T2 component is proportional to the signal intensity of each component. By using three parameters (T2, F, and W), It is possible to know quantitative the crosslinking density and inhomogeneity of the soft materials.