Surface chemical characterization of nanoparticle coated paperboard

The chemical composition of nanoparticle coated paperboard surfaces was characterized. The deposition of SiO2 and TiO2 nanoparticles induced changes in wetting properties of the paperboard surface: a superhydrophilic surface was created by SiO2 nanoparticles and a superhydrophobic surface by TiO2 nanoparticles. Both X-ray photoelectron spectroscopy (XPS) and contact angle (CA) measurements were used to study the surface properties of the samples. The low and high resolution XPS spectra were collected to evaluate the chemical composition before and after nanoparticle deposition. The SiO2 nanocoated sample has the highest values of both O to C and C2 to C1 ratios, which indicates a high relative amount of hydroxyl groups. On the other hand, carbon C1 peak which represents the hydrocarbon type of bonds, is on higher level for TiO2 when compared to the SiO2 nanocoated sample. This may be related to the replacement of hydroxyl groups by aliphatic chains on the superhydrophobic surface of TiO2 nanoparticle coated sample.