Thin Al2O3 barrier coatings onto temperature-sensitive packaging materials by atomic layer deposition

Thin (25 nm) and highly uniform Al2O3 coatings have been deposited at relatively low temperature of 80 and 100 °C onto various bio-based polymeric materials employing the atomic layer deposition (ALD) technique. The work demonstrates that the ALD-grown Al2O3 coating significantly enhances the oxygen and water vapor barrier performance of these materials. Promising barrier properties were revealed for polylactide-coated board, hemicellulose-coated board as well as various biopolymer (polylactide, pectin and nano-fibrillated cellulose) films.

► Al2O3 coatings (25 nm) were deposited at 80 and 100 °C. ► The atomic layer deposition (ALD) technique was used. ► The coating efficiently enhanced the barrier properties. ► Substrates were all bio-based. ► Coatings meet the requirements for food packages.