Barrier properties of Al2O3 and alucone coatings and nanolaminates on flexible biopolymer films

Thin atomic layer deposited (ALD) Al₂O₃ coatings are efficient barriers against gases and vapors. Al₂O₃ coatings are, however, brittle and straining them generates defects that impair barrier properties. Flexibility of ALD-grown Al₂O₃ coatings on biopolymer substrates can be improved by separating thinner Al₂O₃ layers with inorganic-organic alucone layers. The number and size of defects were smaller for these nanolaminates compared to the thick Al₂O₃ films after straining, and hence straining deteriorated the oxygen barrier properties less when applied to the laminates than when applied to the Al₂O₃ coatings.