Brief overview on 2H NMR studies of polysiloxane-based side-chain nematic elastomers

This is a brief overview on recent studies on liquid crystalline elastomers (LCEs) based on polysiloxane chain, in the form of monodomain films, selectively H-2-labeled in different parts of the LCE samples, i.e. on the crosslinker or mesogenic units. H-2 NMR spectroscopic techniques were used to measure the temperature dependence of the quadrupolar splittings, line widths and relaxation times, T-1 and T-2. From these data, several information about the orientational order parameter, S, of various LCE fragments, thermodynamic features of the isotropic-nematic transition and main motional processes could be generalized for this type of elastomers.