Amphotropic liquid crystallinity of N,N'-diundecenoylbenzene-1,4-diamine (DUBDA)

Abstract

N,N'-diundecenoylbenzene-1,4-diamine (DUBDA), an amide with long symmetric aliphatic chains, is shown to exhibit monotropic thermotropic liquid crystallinity as well as lyotropic liquid crystallinity in highly polar solvents on the basis of differential scanning calorimetry, polarized optical microscopy, temperature-variable FTIR, and X-ray diffraction analysis. There are obvious differences between the two mesophases in terms of molecular stacking and driving force, although the two mesophases originate from the same molecule. In addition, a possible lamellar model for the lyotropic mesophase is proposed.