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

Abstract Thin atomic layer deposited (ALD) Al 2 O 3 coatings are efficient barriers against gases and vapors. Al 2 O 3 coatings are, however, brittle and straining them generates defects that impair barrier properties. Flexibility of ALD-grown Al 2 O 3 coatings on biopolymer substrates can be improved by separating thinner Al 2 O 3 layers with inorganic–organic alucone layers. The number and size of defects were smaller for these nanolaminates compared to the thick Al 2 O 3 films after straining, and hence straining deteriorated the oxygen barrier properties less when applied to the laminates than when applied to the Al 2 O 3 coatings.