LASER INTERFEROMETRY FLUORESCENCE QUENCHING STUDY OF THE SOLVENT-SWOLLEN GEL LAYER OF THIN POLY(METHYL METHACRYLATE) FILMS UNDERGOING DISSOLUTION

A new method to analyze experimental results based on laser interferometry and fluorescence quenching (LIFQ) is reported. The method was applied to study the dissolution of thin poly(methyl methacrylate) (PMMA) films. Two fundamental parameters of the solvent-swollen gel layer at the solvent-polymer interface were taken into account: its thickness and its refractive index profile. Good agreement with the experimental results was obtained when using a simple linear profile. We were able to describe the evolution of the gel layer thickness as the dissolution takes place.