Broadline NMR Study of H2O and D2O in Oriented Rayon Fibers

Abstract

The broadline NMR spectra of H₂O and D₂O absorbed in parallel fibers of highly crystalline rayon have been found to consist of two lines, whose separation depends upon the angle between the fiber axis and the magnetic field. The D₂O splitting, resulting from quadrupole perturbation of the nuclear Zeeman levels, was about 10 times greater than the H₂O splitting, produced by direct nuclear dipole‐dipole interaction. Two models for the partial orientation of water molecules are discussed, (I) in which the molecules rotate about a fixed axis, and (II) in which the molecules reorient rapidly about all possible axes, but maintain a small resultant projection, along the fiber axis. Model I is shown to be incorrect for the rayon fibers, on the basis of the combined H₂O and D₂O results; Model II, however, appears to be applicable not only to rayon but to other examples of partially oriented water as well.