Expérimental et théorique
One of the methods for applying a thin layer to glass is to dry a liquid layer previously spread on the surface. During the drying process, vertical gradients in solute concentration can appear, which can lead to the formation of a skin. The presence of a skin can be detrimental to the optical quality of the products: it can alter the morphology of the film and also increase the effects of defects already present on it. However, predicting skin appearance is difficult and skin thickness can be thin, complicating its experimental detection. Our goal is to use Raman spectroscopy to demonstrate skin formation during drying of polymer solutions.