Precise dipolar coupling constant distribution analysis in proton multiple-quantum NMR of elastomers.

摘要: In this work we present an improved approach for the analysis of 1H double-quantum nuclear magnetic resonance build-up data, mainly determination residual dipolar coupling constants and distributions thereof in polymer gels elastomers, yielding information on crosslink density potential spatial inhomogeneities. We introduce a new generic function, use as component fitting function linear superpositions, or kernel fast Tikhonov regularization (ftikreg). As opposed to previously used inverted Gaussian based second-moment approximation, method yields faithful constant distributions, limitations limit are now lifted. A robust proper estimation error parameter is established, demonstrated different inhomogeneous elastomers with distributions.