Síntese e caracterização de fluidos complexos: cristais líquidos liotrópico iônicos

Abstract

Complex fluids constitute a class of materials characterized by dynamic and structural behavior capable of significant reorganization. These reorganizations occur in response to variations in temperature, concentration, or molecular interactions. Within this group, lyotropic liquid crystals stand out for exhibiting unique optical and electrochemical properties, directly linked to the complex supramolecular structures of these systems. This work analyzed how the presence of an ionic liquid influences the structural organization and mesomorphic behavior of lyotropic systems based on potassium laurate, aiming to understand the modulatory role played by the ionic liquid in self-organized systems. For this purpose, the ionic liquid 1-dodecyl-3-methylimidazolium bromide and potassium laurate were synthesized and subsequently used for sample preparation. Characterization was carried out using polarized light optical microscopy and impedance spectroscopy, enabling the investigation of mesophase behavior and the electrochemical responses of the material. Based on the results obtained, it was possible to determine that the addition of the ionic liquid systematically modified the mesomorphic phases, expanding the stability of the calamitic nematic phase. This also promoted the emergence of new organizations, such as the biaxial nematic phase and the discotic phase at higher concentrations. Impedance spectroscopy contributed to identifying structural alterations, revealing consistent changes in the dielectric behavior and ionic dynamics of the system. These findings confirmed that the ionic liquid acts as a structural modulator of lyotropic liquid crystals, influencing micellar packing and physicochemical responses, which highlights the potential of these materials for technological applications and for the development of advanced systems.