Study of hygroscopic properties of the mixture of porous and non-porous materials by using optical techniques

The hygroscopicity of urea/diatom compounds was investigated using the dynamic speckle technique, alongside the study of textural properties through nitrogen sorption. The speckle pattern data was analyzed employing second-order inertia and autocorrelation methods. The optical methods yielded valuable insights into the sample’s hygroscopic behavior, enabling differentiation between samples with varying urea content. Samples containing high levels of urea exceeded the applicable range for nitrogen sorption analysis. Consequently, the dynamic speckle technique emerged as a valuable supplement to traditional methods in such cases.