Strange mass density behaviour of a micellar chiral nematic phase composedof an amphiphilic racemic mixture and its L-enantiomer

Starting from the achiral nematic phase composed of DL-serine hydrochloride decylester (DL-SDE), the change in density has been measured at 20 degrees C as DL-SDE was stepwise replaced by the L-enantiomer. It was found that th e density increased linearly with the replaced mole fraction of the L-isome r. The average difference between the densities of the achiral nematic phas e and intrinsic cholesteric phase was 0.001 g cm(-3). In addition, the dens ity of two chiral solutes, hexahydromandelic acid (HHMA) and mandelic acid (MA) was measured in DL-SDE and decylammonium chloride (DACl) achiral nemat ic phases, respectively. Using a constant composition of the phases and equ imolecular amount of the chiral solutes, the density of the phases containi ng HHMA was smaller than those containing MA. The average density differenc e was larger in the DL-SDE phase (0.0025 g cm(-3)) than in the DACl phase ( 0.0017 g cm(-3)). These phenomena are novel and have been initially recogni zed by density measurements.