At the air/water interface, 4′-8-alkyl[1,1′-biphenyl]-4-carbonitrile (8CB) domains with different thicknesses coexist in the same Langmuir film, as multiple bilayers on a monolayer. The edge dislocation at the domain boundary leads to line tension, which determines the domain shape and dynamics. By observing the domain relaxation process starting from small distortions, we find that the line tension λ is linearly dependent on the thickness difference ΔL between the coexisting phases in theComparisons with theoretical treatments in the literature suggest that the edge dislocation at the boundary locates near the center of the film, which means that the 8CB multilayers are almost symmetric with respect to the air/water interface.

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Bulk alignment of liquid crystalline phases is achieved using self-organized thin films of bent-core mesogens transferred to a glass substrate by Inverse-Langmuir-Schaefer (ILS). We discuss the importance of the architecture of the aligning molecules (hydrophilic/hydrophobic balance for film stability as well as other structural factors) andshow the dependence of the density of the monolayer with the alignment induced by it. These results are compared with molecular simulations for further understanding of molecular packing and interfacial interactions.

When compressed in the intermediate temperature range below the chain-melting transition yet in the low-pressure liquid phase, Langmuir monolayers made of chiral lipid molecules form hierarchical structures. Using Brewster angle microscopy to reveal this structure, we found that as the liquid monolayer is compressed, an optically anisotropic condensed phase nucleates in the form of long, thin claws. These claws pack closely to form stripes. This appears to be a new mechanism for forming stripes in Langmuir monolayers. In the lower temperature range, these stripes arrange into spirals within overall circular domains, while near the chain-melting transition, the stripes arrange into target patterns.We attributed this transition to a change in boundary conditions at the core of the largest-scale circular domains.

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