Propriedades não lineares de materiais nanoestruturados

Abstract

This study is dedicated to investigating the thermo-optical and nonlinear response of complex fluids such as liquid crystals, carbon quantum dots, and dyes in various solvents. Using the time-resolved z-scan technique, we explore the impact of adding carbon quantum dots derived from dansyl chloride (CD-DsCl) on the nonlinear refractive coefficient in planar liquid crystal samples. In the study of CD-DsCl addition in liquid crystals, we analyze the dependence of the nonlinear optical response on temperature, especially near the smectic-A to nematic and nematic to isotropic phase transitions. We also investigate the effects of an external electric field on these samples. Our preliminary results indicate that liquid crystal samples doped with carbon quantum dots may exhibit an enhanced nonlinear optical response, depending on the intensity of the applied external field. This study contributes to the understanding of nonlinear optical phenomena in liquid crystal systems doped with carbon quantum dots. We also investigate the effect of solvents on the nonlinear optical properties of the tautomeric forms of methyl orange through experimental approaches. Our results show that in the presence of different solvents,methylorangeexhibitsanegativenonlinearopticalbehavior,andaredshiftinitslinear absorption is observed as the solvent polarity increases. This work contributes to advancing the understanding of the basic physics of organic compounds.