Hygroscopic properties of the mixture of porous and non- porous materials by using speckle techniques

RUTH D. MOJICA SEPÚLVEDA; LUIS J. MENDOZA HERRERA; CARMEN I. CABELLO; GUILLERMO BERTOLINI; MERCEDES MUÑOZ; EDUARDO E. GRUMEL; MYRIAM C. TEBALDI; MARCELO R. TRIVI

San José

Congreso; RIAO OPTILAS 2023; 2023

Red Iberoamericana de Óptica

Green Chemistry represents an alternative to protect the environment. Compoundswith urea are widely used in green chemistry, for fertilizers making process, biocarbon,cellulose solvent and biomass pretreatment in biorefinery processes In all industryapplication, it is essential to study the samples textural (specific surface area, porosity, etc.)and hygroscopic properties to determine the adequate composites proportions for each case.The nitrogen sorption is among the most widely used techniques to obtain the texturalproperties. However, this technique is not adequate for materials with a heterogeneous surfaceand different sorption regions. Note that it is not possible to use the nitrogen sorptiontechnique for urea. Then, the dynamic speckle represents an interesting alternative for texturalparameters determination.In our proposal, the absorption and/or adsorption of water in Urea/Diatom composites areanalysed by using the dynamic speckle technique. The second order moment of inertia as afunction of time allows us to separate the adsorption and absorption characteristic times of thecomposites. These results give information about the behaviour of each sample and the texturalproperties changes. Finally, we confirm that the information arise from optical techniques arecomplementary to those obtained by the nitrogen sorption technique.