Cholic acid was coupled to an alkyl tail via three different connecting groups, amide, urea, and ester group, and the gelation capabilities of these compounds in different solvents were compared. Both amide and urea derivatives form one-component gels. They give transparent and stable gels in aromatic solvents through a hydrogen bonded network of monomolecular fibers. Structural variations give information about the molecular requirements for gelation. A new kind of two-component gel was found for the ester derivatives with two carbohydrates, isomannide and isosorbide. Formation of wormlike, inverted micelles causes gelation of apolar solvents. The optimal stoichiometry of the co-gelators lies close to 1:1.

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Side-chain liquid-crystalline copolymers from maleic anhydride and 1-alkenes carrying biphenyl mesogens have been modified by reaction of the anhydride moieties with different mesogenic alcohols to give maleic acid monoesters. FTIR and 1H NMR showed high degrees of modification. Grafting methoxybiphenyl-containing alcohols having different spacer lengths onto methoxybiphenyl-containing polymers yielded polymers exhibiting smectic A mesophases with a variable degree of interdigitation. The glass transition temperature decreased with spacer length, whereas the isotropization temperature remained almost constant. Grafting azobenzene-containing alcohols onto methoxybiphenyl-containing copolymers yielded side-chain liquid-crystalline polymers exhibiting nematic mesophases. The effect of the 4‘-azobenzene terminal group on the temperature window of the mesophase was CN > OMe > F > H. Grafting a cyanostilbene-containing alcohol onto a methoxybiphenyl-containing copolymer resulted in a polymer that exhibited a smectic E mesophase with complete interdigitation of side chains. Introducing methoxybiphenyl mesogens into cyanobiphenyl-containing copolymers or vice versa resulted in polymers with smectic A mesophases. Furthermore, an increase in isotropization temperatures was observed in comparison with polymers carrying only one type of mesogen. This indicates specific favorable interactions between unlike mesogens.

Two novel polymerizable double-chained ammonium amphiphiles carrying mesogenic cyanobiphenylyloxy units have been synthesized containing methacrylate in the headgroup or diacetylene groups in the hydrophobic tails. These compounds form bilayer vesicles upon dispersion in water. Polymerization increases the vesicle stability toward solubilization by a nonionic surfactant. The stacking of the cyanobiphenylyloxy units in the bilayer is directly monitored by the extent of the blue shift of the absorption maximum. Upon polymerization a decrease in blue shift is observed, reflecting a decrease in the ordering of the amphiphile molecules. This effect is stronger when polymerization occurs in the hydrophobic tails than in the headgroup region.

This paper describes a series of cholic acid based facial amphiphiles carrying three ionic headgroups. Their micellization behavior in water was studied as a function of spacer length and alkyl tail length: both were found to have a small influence on the critical micellization concentration (cmc). Isothermal titration calorimetry was used to gain information on the thermodynamics of micellization. These surfactants show rather normal temperature-dependent behavior: Gibbs energy of micellization is almost constant, cmc increases, and enthalpy of micellization decreases with temperature, and both entropy and enthalpy contribute to the micellization.