Interfacial Spin–Spin Coupling in Wood by 2D Time-Domain NMR

Abstract

Magnetization exchange between the solid-wood component and water was studied in hydrated aspen wood by 2D NMR time-domain spectroscopy. Analysis of the relaxation results for exchange shows that a three-site system (water and two wood components) is involved and that the water protons are strongly coupled (a wood-to-water exchange rate of 640 s⁻¹) to the water-accessible wood protons, which in turn are less strongly coupled (a wood-to-wood exchange rate of 64 s⁻¹) to the water-inaccessible wood protons.