An amphiphile system forming a lyotropic blue phase

Abstract

A partial phase diagram of the potassium N-tetradecanoyl-L-alaninate/decanol/water (+10 per cent C_sCI) system has been charted using polarizing microscopy, laser diffraction, and NMR spectroscopy. At low amphiphile concentrations, a chiral nematic Ch_D phase with disc-like micelles occurs and at higher concentrations there occur a chiral nematic, Ch_C phase with cylindrical micelles and a chiral version of a dimensionally-ordered (probably rectangular or hexagonal) phase. Between the Ch_c phase and the genuine isotropic liquid there is a chiral isotropic phase which appears to be a micellar analogue of a thermotropic blue phase. This isotropic chiral I_c phase showed flow birefringence.