Spin probe orientation distribution functions in aligned nematic liquid crystal

Orientation distribution functions of nitroxide spin probe in nematic liquid crystal 5CB embedded into porous polyethylene film were determined at 295 K and at 77 K by numerical simulation of electron paramagnetic resonance (EPR) spectra. The procedure of simulation of EPR spectra at 77 K in the absence of molecular mobility of spin probe molecules allows determination of non-equilibrium orientational distribution function in supercooled liquid crystals. The suggested procedure yields an orientation distribution function of orientational axis of a spin probe molecule. Orientation distribution functions for the sample at 295 K and 77 K were found to be similar.