Dynamic Speckle Laser technique as an efficient and simple method for the analysis of hygroscopic and textural properties of oxides

CARMEN I. CABELLO; RUTH DARY MOJICA SEPÚLVEDA; EDUARDO E. GRUMEL; LUIS J. MENDOZA HERRERA; MARCELO R. TRIVI; DELIA GAZZOLI

Roma

Congreso; 2nd Global Summit & Expo on Laser Optics & Photonics; 2018

Scientific Federation

The water adsorption capacity as a function of time of adsorbent materials is a relevant property that must be determined for its multiple applications. Conventional methods consist of introducing a sample in water and representing the time-dependent weight change to determine the amount of water adsorbed. Normally, the hygroscopic properties of the sample can be characterized by the well-known TG-DTA, FTIR and BET methods.Dynamic laser speckle (DLS) is an optical technique that has been used for several applications in biology, medicine and industry. It is based on a scattering phenomenon that occurs when a coherent laser light illuminates an active surface.In this paper, we propose to use DLS method to estimate the hydro-adsorption properties of oxidic surfaces of interest as catalytic supports such as: ZrO2, Al2O3, SiO2 and minerals based on aluminosilicates such as clays (kaolinite, montmorillonite, zeolites). We try to correlate the speckle measurements with the specific surface area provided by physicochemical methods, such as the well-known BET and other methods based on the adsorption of N2 solids. We show some experimental results that demonstrate the validity of the DLS technique for these applications and compare them with those obtained by conventional techniques.