Phase Transformation of Swollen Thermotropic Liquid Crystals Studied by X-Ray and²H-NMR Measurements

Revisiting Smectic E Structure through Swollen Smectic E Phase in Binary System of 4-Nonyl-4′-isothiocyanatobiphenyl (9TCB) and n-Nonane

“…A similar dependence was reported for swelling of SmA phase. 35 The behavior is in contrast to that of lyotropic liquid crystals formed in neutrally charged lipid−water systems, where the repulsion between lipid layers is enhanced by thermal agitation. 42−44 Namely, QB mixtures in thermotropic systems are not the same completely as lyotropic lipid−water systems.…”

“…This structure is similar to the induced SmA phase in the 7CB−n-heptane binary system 33 and swollen SmA phase in a binary system between 4-(1-methylheptyloxycarbonyl)phenyl 4′-octyloxybiphenyl-4-carboxylate (MHPOBC) and noctane. 35 Even if the amount of absorbed n-alkane becomes large, the structural correlation along the stacking direction remains through the n-alkane molecules as bridging parts.…”

“…33 Besides, there is, for example, a swollen SmA structure observed in a binary system between 4-(1-methylheptyloxycarbonyl)phenyl-4′-octyloxybiphenyl-4-carboxylate (MHPOBC) and n-octane. 35 These suggest that the effective "repulsion" between aromatic core and alkyl chain probably works also in SmE phase of nTCB with a large n.…”

“…A simpler structure like SmA phase is also related to the microphase segregation: SmA phase is induced in nematogenic 7CB, a member of the most famous thermotropic series n CB, by adding n -heptane . Besides, there is, for example, a swollen SmA structure observed in a binary system between 4-(1-methylheptyloxycarbonyl)phenyl-4′-octyloxybiphenyl-4-carboxylate (MHPOBC) and n -octane . These suggest that the effective “repulsion” between aromatic core and alkyl chain probably works also in SmE phase of n TCB with a large n .…”

NMR of liquid crystals and micellar solutions

“…Particularly, the quadrupolar splitting indicate the aliphatic molecules to be averagely oriented parallel to the director of the smectogens. 27 Concerning structural investigation on small molecules, the 1 H NMR spectra of biphenyl dissolved in three different thermotropic uniaxial solvents have been analyzed, and the resulting temperature-dependent dipolar coupling sets have been analyzed in order to obtain the distribution of the inter-ring angle. 28 3.2 Lyotropic liquid crystals A lyotropic L.C.…”