Evidence of capillary action in multilayered fibrous media observed with THz spectroscopy

Paper i proceeding, 2023

Here we investigate the applicability of the stratified media model to complex, multilayered media. THz reflectivity spectra of drying cellulose-based material show pronounced, frequency dependent reflectivity reduction below dry reflectivity. Analysis suggests the remaining water is distributed at the top surface of the paper thus consistent with a capillary in opposition to gravity.