DEBYE-STOKES-EINSTEIN FRACTIONAL LAW IN A POLYMERIC LIQUID-CRYSTAL - A NONLINEAR ESR STUDY BY USING SPIN PROBES WITH DIFFERENT SYMMETRIES

The reorientation of spin probes with very different aspect ratios, di ssolved in a polymeric liquid crystal, is studied by non-linear Electr on Spin Resonance. A scaling law between the rotational correlation ti me tau and the macroscopic viscosity, as measured via the dynamic shif t factor a(T), is found. A discussion on the current interpretations o f the scaling, which takes the form tau proportional to a(T)(xi) with 0 less than or equal to xi less than or equal to 1, is given.