The chain motion model developed in part I is shown to be consistent with a range of NMR data onLagr;phase lipid multilayers and vesicles. A simple treatment of correlation effects within the intramolecular (crankshaft) rotations in the weak collision limit leads to a realisticT1profile along the acyl chain, despite the assumption of a constant order parameter profile. The observed dependence ofT1on chain length is not reproduced however. The measured activation energy (sim;13 kJ/mol) forT1relaxation is consistent with the model, as are the rsquo;rsquo;anomalouslyrsquo;rsquo; lowT1and Cndash;D order parameters observed on the methene groups in monounsaturated chains. A very small angular dependence for the2H methyleneT1at high frequency (gsim;50 MHz) is suggested. This accords with observation and is a direct consequence of the crankshaft geometry. At temperatures sufficiently aboveTm, the nematic fluctuation model of part I semiquantitatively predicts the components of multilayerT1andT1rgr;relaxation rates linear in ohgr;minus;1/2. However, the description fails for ohgr;sim;108andTsim;Tm, in a manner possibly indicating nonrigid chain axis fluctuation on this time scale. A twohyphen;dimensional formulation of the nematic model provides a simple description of small vesicle1H and2H NMR linewidths, consistent with the experimental data.
展开▼
