Carbon dioxide diffusion at different relative humidity through coating of cellulose nanocrystals for food packaging applications

•CO2 permeability is affected by low moisture content in CNCs coatings.•The observed increase of PCO2 is due to solubility and to the pH of coating.•O2 permeability increases only once the coating structural coherence is lost.•PCO2/ PO2 ratio (selectivity) at RH 20% is 50 times higher than at 0%.•RH and pH values can be potentially adjusted for appropriate MAP design.