THE LOW-FREQUENCY RAMAN-SPECTRUM OF LITHIUM PHENYL STEARATE AND ITS RELEVANCE TO POLYSTYRENE

The low frequency Raman spectrum of a surfactant molecule, lithium phe nyl stearate, in a reversed hexagonal phase is reported. A broad peak, centred around 59 cm-1, is observed and shows similarities in both po sition and width with a peak in the spectrum of amorphous polystyrene. It is concluded that the origins of these peaks are similar, involvin g a phenyl group torsion. This similarity has important implications, in view of alternative models previously applied to polystyrene: it is suggested that 'structural' models, such as the elastic sphere and fr acton models, can be dismissed as possible explanations of this partic ular Raman peak. One is left with the possibility that tunnelling in t wo-level systems is responsible for the Raman peak in both materials a nd for low temperature thermodynamic behaviour of polystyrene.