Liquid crystal codendrimers with a statistical distribution of phenolic and mesogenic groups: behavior as Langmuir and Langmuir-Blodgett films

The first series of carbosilane liquid crystal codendrimers with groups of different polarity has been synthesized. The chemical structure of the newly synthesized materials and the composition of the codendrimers were studied by NMR spectroscopy and MALDI-TOF MS. It was found that the codendrimers tend to form stable Langmuir films at the air-water surface. The influence of composition and generation number on surface pressure-surface area isotherms and film stability was studied. Brewster angle microscopy confirmed the different phase behavior for monolayers of different codendrimer composition and generation number. It was found that side groups of fifth-generation codendrimers do not segregate, unlike those of lower generations. Langmuir-Blodgett films on solid substrates were obtained by the vertical dipping method. X-ray diffraction showed that the codendrimers with 75% of hydrophobic mesogenic terminal groups formed ordered layers parallel to the substrate.