The orientation dependence of deuterium transverse relaxation rates obtained from unoriented model membrane systems

Abstract A quadrupolar-echo Fourier transformation technique was used to measure T 2 as a function of director orientation in model membrane systems from powder spectra with residual quadrupolar splittings. The relaxation function is exponential for all systems and orientations, giving rise to Lorentzian-broadened Pake doublet lines. From the relaxation time profile versus director orientation, conclusions are drawn about molecular motions along curved surfaces. An advantage of this technique is that no macroscopic orientation of membrane systems between glass plates is necessary.