Surface hydrophobic modification of chitosan thin films by hexamethyldisilazane plasma deposition: effects on water vapour, CO₂ and O₂ permeabilities

This study evaluated the effects of the deposition of a thin hydrophobic silicon coating onto a polysaccharide film's surface. The goal was to improve the water vapour barrier of the hydrophilic film in order to increase the film's usefulness in packaging applications. A cold‐plasma technique was used to create a thin hexamethyldisilazane deposition on a chitosan film surface. The modification was investigated using Fourier transform infrared. The effect on the surface was characterized through contact angle measurements and degree of swelling. A significant reduction in hydrophilicity and water vapour permeability was observed. Gas barrier measurements indicated that there were no substantial differences in O 2 and CO 2 permeabilities under the conditions used in this investigation.