Refractive index shift from liquid to solid in the drying process

Abstract Understanding the drying kinetics of paints and coatings is crucial in various industrial applications due to their significant impact on reflective properties. This study investigates the dynamic changes in the refractive index of adhesives and varnishes during their transition from liquid to solid states upon drying, while the imaginary part of the refractive index was measured only in the fully dried samples. Our results reveal that the refractive indices of liquid varnishes and lacquers change during the drying process, increasing from 1.382 to 1.5119. Similarly, the refractive indices of adhesives change from 1.440 to 1.452 during drying. The use of refractive index data enhances the optimization of drying process and offers deep insights into the materials’ optical characteristics, crucial for understanding material behavior during drying and its influence on the end-product’s performance.