Utilização da técnica da lente térmica para o estudo das propriedades termo-ópticas de meios espalhadores de luz

Abstract

In this work, the study and the characterization of the thermal and optical properties of the absorption in solutions containing light scattering nuclei through the Thermal Lens (LT) technique were carried out. Also allied LT technique and the Lambert-Beer law (LB) to study and to distinguish the effects of absorption and scattering of light in liquid media. For this purpose, samples of colloidal solutions of silicon dioxide, SiO2, known as silica, were prepared in alcohol (ethanol). We obtain from the LT technique along with the law of LB the coefficients of absorption, scattering and extinction of the samples. Moreover, the value found for the thermal diffusivity is very close to the theoretical value. We also conclude that due to non-homogeneous samples, they have a poor optical quality, consequently they present a variation in the value of the thermal diffusivity found.