Interactions of ink colourants with chemically modified paper surfaces concerning inkjet print improvement

This study reports the modification of the paper surface by the application of different chemicals and its effect on the paper structural and surface properties and inkjet print quality parameters. 3-(N,N-dimethylmyristylammonio)propanesulphonate and hexadecyltrimethylammonium bromide, as zwitterionic and cationic surfactants, respectively, and a cationic polymer, poly(diallyldimethylammonium) chloride (PD) were used for the surface treatments. It was found that, in general, the surface treatments have a negligible effect on the paper structural properties. However, a significant effect was found on the surface energy parameters, and surface chemical composition as accessed by XPS. The modified papers and the base paper were printed on two thermal inkjet printers: Lexmark X-8350 and HP Photosmart Pro B8850. The paper modified with PD exhibited the best print quality on both printers yielding high colour properties (gamut area increase of 12% and 11%, respectively), good line and dot print quality. The print quality results were interpreted taking into account the nature (dyes or pigments) and molecular structure (determined by FTIR spectroscopy) of the inks colourants, paper surface properties, and the paper surface–ink interactions. Overall, the presence of cationic groups and a high polar component at the paper surface favour the fixation of sulphonate-containing dyes while a low paper surface energy and the evidence of aggregation/flocculating properties of the modifier (PD) helps the inks pigments immobilization.