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Nonvolatile hydrophobic oils can be reversibly spread into liquid-condensed Langmuir films, if the material is in or close to liquid-crystal phase in the bulk. This extraordinary spreading mechanism may have impact on the nature of colloidal and biomembrane stabilities.

Induced smectic phases of 5CB-EBBA binary mixtures were investigated with respect to the structures, stabilities, and molecular motion. The highest stability of the ordered smectic phase was obtained when 5CB and EBBA were mixed at 1:2. At the same ratio, the transferred charges between 5CB and EBBA took the maximum, indicating the direct correlation of the induced phase to the charge-transfer interaction. Whereas, the molecular motion monotonically slowed down with increasing EBBA, which is ascribed to the decrease of the free volume. The stability and the slow molecular reorientation may be independently controlled in the induced smectics. [ABSTRACT FROM AUTHOR]

The flow orientation effects in Langmuir-Blodgett thin films were investigated. The results showed that the final distribution function was dependent on the initial conditions of the particle as each particle recalled the flow history on the water surface. However, when the initial point was too far from the substrate, the final distribution function was determined by a dimensionless number.

The diffusion-adsorption method was used to examine the interface-adsorbed complex Langmuir-Blodgett (LB) films of arachidic acid and water-soluble, mesosubstituted cyanine dyes. The formation of either J or H aggregate was found to be dependent on the ethyl or methyl substituent group introduced and is measured by photoluminescence and microscopic spectroscopy. The molecular arrangements in the aggregates were determined based on Davydov'stheory and the extended dipole model. Schottky-type cells were used to study the dependence of photoelectric properties of the LB films on aggregate type.

Orientational correlations in Langmuir monolayers of nematic and smectic-C liquid crystal (LC) phases are investigated by molecular dynamics simulation. In both phases, the orientational correlation functions decay algebraically yet with the different exponents of 1.9 and 0.2 for the nematic and the smectic-C monolayers, respectively. The power law decay, i.e., the absence of long-range orientational order, means the both monolayers should be the ideal 2D system with a continuous symmetry, whereas the large difference in the exponents of power law gives rise to the crucial difference in their optical properties; the nematic monolayer is optically isotropic while the smectic-C monolayer exhibits an anisotropy on the length scale of visible light. Since the exponent is inversely proportional to the molecular exchange energy, the averaged molecular interaction in the nematic monolayer should be an order of magnitude smaller than that in the smectic-C monolayer, which is ascribed to the low molecular density and the weak molecular dipole due to the water molecule. The relation between the molecular interaction and the orientational correlation calculated for the 2D LC system offers much information not only about the 2D LCs but also on the bulk system. [ABSTRACT FROM AUTHOR]

Presents a study that investigated the in-plane anisotropy of the Langmuir-Biodgett films of a merocyanine-fatty acid mixed system. Theory used in the study; Details of the experiment; Results and discussion.

Focuses on a study which analyzed the effects of substituent groups for the aggregate formation in arachidic-acid-cyanine-dye complex Langmuir-Blodgett films. Configuration of dye molecules in aggregation; Absorption spectra of the subphase solutions; Information on the surface pressure-area isotherms.

Investigates the Davydov splitting in arachidic acid-cyanine dye complex Langmuir-Blodgett films. Preparation of the sample; Results of the study; Conclusion.