Deuterium Magnetic Resonance Study of Perdeuterated Para-Azoxy-Anisole in Solution in a Linear Nematic Polymer

Abstract

Abstract A deuterium magnetic resonance (DMR) study of perdeuterated para-azoxy-anisole (PAAd14) in solution in the linear nematic thermotropic polymer DDA9-L is presented. Three concentrations are considered: 5%, 10%, 50% by weight. Information on the nature of the various phases formed with the PAA/DDA9-L mixtures is deduced from the shape of the DMR spectra. Information concerning the molecular structure, conformation and orientational order of PAA is deduced from the temperature and concentration dependence of the six quadrupolar splittings, by means of a model previously used for bulk nematic PAAd14. It is found that in the mixtures, the nematic order parameter of PAA is higher, and the molecular conformation slightly different, than in bulk. It appears that PAAd14 dissolved at low concentration (≤10% w/w) is a good DMR spin probe for the study of the DDA9 systems.