Nuclear Magnetic Resonance Studies of Water Sorbed on Fibrous Materials

Abstract

Nuclear magnetic resonance of the water molecules sorbed on the native cellulose, “mulbery paper” was studied.
The measurements of the line width were made under the condition of water content ranging from 10 to 180% at 20°C, by using Varian high resolution type spectrometer.
Within the range of 10 to 20%, the line widths rapidly decreased with increasing water content, and gradually decreased beyond the region. Although this tendency was similar to that of dielectric relaxation, the experimental value of τ_N obtained from Kubo-Tomita equation was much greater in the order of magnitude than that of the dielectric relaxation time τ_D. Accordingly, τ_N and τ_D do not satisfy the BPP’s relation of τ_N=1⁄3·τ_D. This result suggested to us that the water molecules in the sorbed state do not rotate with spherical symmetry like in the liquid state.