Physics Commons^™

Absolute values for the elastic constants and viscosities are reported in the nematic phase for two dimers based upon the monomer 4.4'-dipentyloxyphenylbenzoate. One dimer has an even number of methylene units in the spacer and, in consequence, is approximately straight in the all-trans conformation. The other dimer has one less methylene unit, and is therefore bent. We find that the ratio K33/K11 for the odd dimer is reduced relative to that for the even member of the series. Moreover, we find that the absolute elastic constants for the odd dimer are of order one-half that of the ...

Light scattering measurements in the nematic phase are reported for two dimers based upon the monomer 4,4'-dipentyloxyphenylbenzoate. One dimer has an even number of methylene units in the spacer and, in consequence, is approximately straight in the all-trans conformation. The other dimer has one less methylene unit in the spacer and is, therefore, bent at the spacer group. We find that the ratio of the twist to splay elastic modulus is nearly the same for both species, but that the ratio of the bend to splay modulus is considerably smaller in the bent dimer.