A novel transition in the lyotropic cholesteric mesophase induced by the helix sense inversion of α-helical poly(β-phenethyl l-aspartate)

Abstract

Abstract Poly(β-phenethyl l-aspartate) was found to exhibit a thermally-induced helixhelix transition between the low temperature (right-handed) and the high temperature (left-handed) forms in the lyotropic cholesteric solution. The transition takes place sharply and reversibly at around 90°C, the birefringent character of the cholesteric mesophase being maintained throughout the transition range. The cholesteric helical sense, as well as the cholesteric pitch, were determined as a function of temperature. The results suggest that the inversion of the α-helical screw sense triggers a reversal of the cholesteric macro-helix.