Orientation-dependent proton double-quantum NMR build-up function for soft materials with anisotropic mobility

摘要: Abstract In recent years, the analysis of proton double-quantum NMR build-up curves has become an important tool to quantify anisotropic mobility in different kinds soft materials such as polymer networks or liquid crystals. former case, data provides a measure orientation-dependent residual (time-averaged) dipolar couplings arising from segmental motions, informing about length and state local stretching network chains. Previous studies macroscopically ordered, i.e. stretched, were subject limitation that detailed curve on basis universal “Abragam-like” (A-l) function valid for multi-spin system was only possible isotropic orientation-averaged response. This situation is here remedied by introducing generic anisotropically mobile protonated molecular segment. We discuss application modeling stretched measured at orientations with respect magnetic field, present validation fitting liquid-crystal molecules oriented field.