Applicability of FTIR and Raman spectroscopic methods to the study of paper-ink interactions in digital prints

Vibrational spectroscopic methods are widely used in analyzing materials both in xy- and z-directions. The need to gain a deeper understanding of the print durability, especially the light fastness of ink jet prints and toner adhesion mechanisms in electrophotography, calls for analytical techniques that are capable of detecting both the physical and chemical state of prints. The sample sets used to study the applicability of various FTIR and Raman techniques to analyzing paper-ink interactions included ink jet prints with the light exposure time as a variable, and electrophotographic prints fixed at different conditions. Because of their versatility and ability to detect features from inks, toners and papers, Raman and FTIR spectroscopy proved to be suitable for studying paper-ink interactions. In addition, these methods also detected changes in the spectra due to light exposure and fixing. In examining inkjet prints on coated papers, FTIR-ATR, confocal Raman and UV Resonance Raman spectroscopy (UVRRS) turned out to be the most suitable methods for studying the light fastness of the prints. In studying the adhesion of electrophotographic prints, various FTIR methods seemed to be particularly useful because of their ability to detect hydrogen bonding.